Berberine as a natural source inhibitor for mild steel in 1 M H 2SO 4

NASA Astrophysics Data System (ADS)

Li, Yan; Zhao, Peng; Liang, Qiang; Hou, Baorong

2005-12-01

Berberine was abstracted from coptis chinensis and its inhibition efficiency on corrosion of mild steel in 1 M H 2SO 4 was investigated through weight loss experiment, electrochemical techniques and scanning electronic microscope (SEM) with energy disperse spectrometer (EDS). The weight loss results showed that berberine is an excellent corrosion inhibitor for mild steel immersed in 1 M H 2SO 4. Potentiodynamic curves suggested that berberine suppressed both cathodic and anodic processes for its concentrations higher than 1.0 × 10 -4 M and mainly cathodic reaction was suppressed for lower concentrations. The Nyquist diagrams of impedance for mild steel in 1 M H 2SO 4 containing berberine with different concentrations showed one capacitive loop, and the polarization resistance increased with the inhibitor concentration rising. A good fit to Flory-Huggins isotherm was obtained between surface coverage degree and inhibitor concentration. The surface morphology and EDS analysis for mild steel specimens in sulfuric acid in the absence and presence of the inhibitor also proved the results obtained by the weight loss and electrochemical experiments. The correlation of inhibition effect and molecular structure of berberine was then discussed by quantum chemistry study.

Determination of clothing evaporative resistance on a sweating thermal manikin in an isothermal condition: heat loss method or mass loss method?

PubMed

Wang, Faming; Gao, Chuansi; Kuklane, Kalev; Holmér, Ingvar

2011-08-01

This paper addresses selection between two calculation options, i.e heat loss option and mass loss option, for thermal manikin measurements on clothing evaporative resistance conducted in an isothermal condition (T(manikin) = T(a) = T(r)). Five vocational clothing ensembles with a thermal insulation range of 1.05-2.58 clo were selected and measured on a sweating thermal manikin 'Tore'. The reasons why the isothermal heat loss method generates a higher evaporative resistance than that of the mass loss method were thoroughly investigated. In addition, an indirect approach was applied to determine the amount of evaporative heat energy taken from the environment. It was found that clothing evaporative resistance values by the heat loss option were 11.2-37.1% greater than those based on the mass loss option. The percentage of evaporative heat loss taken from the environment (H(e,env)) for all test scenarios ranged from 10.9 to 23.8%. The real evaporative cooling efficiency ranged from 0.762 to 0.891, respectively. Furthermore, it is evident that the evaporative heat loss difference introduced by those two options was equal to the heat energy taken from the environment. In order to eliminate the combined effects of dry heat transfer, condensation, and heat pipe on clothing evaporative resistance, it is suggested that manikin measurements on the determination of clothing evaporative resistance should be performed in an isothermal condition. Moreover, the mass loss method should be applied to calculate clothing evaporative resistance. The isothermal heat loss method would appear to overestimate heat stress and thus should be corrected before use.

Effects of tetraamine crosslinking agents on the thermomechanical properties of PMR polyimide composites

NASA Technical Reports Server (NTRS)

Delvigs, P.

1976-01-01

The effects were investigated of partial substitution of tetraamine crosslinking agents for diamine reactants on the thermomechanical properties of PMR polyimide resins and graphite fiber-reinforced composites. The effect of tetraamine content on isothermal weight loss, glass transition, and softening temperatures of neat resin samples is discussed. Composites were fabricated using PMR methodology. Monomeric solution of various stoichiometric ratios was used to impregnate Hercules HTS graphite fiber. The mechanical property retention characteristics of the composites at 316 C (600 F) are described.

COREST: A FORTRAN computer program to analyze paralinear oxidation behavior and its application to chromic oxide forming alloys

NASA Technical Reports Server (NTRS)

Barrett, C. E.; Presler, A. F.

1976-01-01

A FORTRAN computer program (COREST) was developed to analyze the high-temperature paralinear oxidation behavior of metals. It is based on a mass-balance approach and uses typical gravimetric input data. COREST was applied to predominantly Cr2O3-forming alloys tested isothermally for long times. These alloys behaved paralinearly above 1100 C as a result of simultaneous scale formation and scale vaporization. Output includes the pertinent formation and vaporization constants and kinetic values of interest. COREST also estimates specific sample weight and specific scale weight as a function of time. Most importantly, from a corrosion standpoint, it estimates specific metal loss.

Corrosion Behavior of Aluminum Alloys in Acidic Media

NASA Astrophysics Data System (ADS)

Ramli, Rosliza; Seoh, S. Y.; Nik, W. B. Wan; Senin, H. B.

2007-05-01

The corrosion inhibition of Al and its alloys are the subject of tremendous technological importance due to the increased industrial applications of these materials. This study will report the results of weight loss, polarization and electrochemical impedance spectroscopic (EIS) measurements on the corrosion inhibition of AA6061 and AA6063 aluminum alloys in acidic media using sodium benzoate as an inhibitor. The results showed that addition of sodium benzoate retards the rate of dissolution and hence inhibits the corrosion of the aluminum alloy in acidic media. The inhibition efficiency increases with the increase of immersion time in acetic acid however it displays a different behavior in sulfuric acid. Langmuir adsorption isotherm fits well with the experimental data. EIS studies showed that there was a significant increase in overall resistance after addition of sodium benzoate, when compared to the case without inhibitor. Langmuir adsorption isotherm fits well with the experimental data.

Phytochemical compounds and anti-corrosion activity of Veronica rosea.

PubMed

Ouache, Rachid; Harkat, Hassina; Pale, Patrick; Oulmi, Kafia

2018-05-16

The aim of this work is the phytochemical study of the butanolic extract of the aerial parts of Veronica rosea. Four compounds 1-4 have been isolated using different chromatographic methods. The structures of these compounds were determined by NMR spectral analysis and mass spectroscopy. The adsorption and anticorrosion effects of this extract were investigated towards the corrosion of copper in 1 M HNO 3 aqueous by the weight loss technique and potentiodynamic polarization. The results showed that the butanolic extract is a good inhibitor and the inhibition efficiency increases with increasing of concentration of the inhibitor. The adsorption of this extract on the copper specimen surface was spontaneous and obeyed the Langmuir's adsorption isotherm. Large value of adsorption equilibrium Constant (K ads  = 35 L g -1 ) was obtained. The polarization experiments confirmed the data obtained by gravimetric weight-loss. Tafel plot of polarization curves indicates that the extract acts as a mixed type inhibitor.

Some aromatic hydrazone derivatives as inhibitors for the corrosion of C-steel in phosphoric acid solution.

PubMed

Fouda, Abd El-Aziz S; Al-Sarawy, Ahmed A; Radwan, Mohamed S

2006-01-01

The effect of furfural benzoylhydrazone and its derivatives (I-VII) as corrosion inhibitors for C-steel in 1M phosphoric acid solution has been studied by weight-loss and galvanostatic polarization techniques. A significant decrease in the corrosion rate of C-steel was observed in the presence of the investigated inhibitors. This study revealed that, the inhibition efficiency increases with increasing the inhibitor concentration, and the addition of iodide ions enhances it to a considerable extent. The effect of temperature on the inhibition efficiency of these compounds was studied using weight-loss method. Activation energy (E(a)*) and other thermodynamic parameters for the corrosion process were calculated and discussed. The galvanostatic polarization data indicated that, the inhibitors were of mixed-type, but the cathode is more polarized than the anode. The adsorption of these compounds on C-steel surface has been found to obey Frumkin's adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

Co-pyrolysis characteristics of sawdust and coal blend in TGA and a fixed bed reactor.

PubMed

Park, Dong Kyoo; Kim, Sang Done; Lee, See Hoon; Lee, Jae Goo

2010-08-01

Co-pyrolysis characteristics of sawdust and coal blend were determined in TGA and a fixed bed reactor. The yield and conversion of co-pyrolysis of sawdust and coal blend based on volatile matters are higher than those of the sum of sawdust and coal individually. Form TGA experiments, weight loss rate of sawdust and coal blend increases above 400 degrees C and additional weight loss was observed at 700 degrees C. In a fixed bed at isothermal condition, the synergy to produce more volatiles is appeared at 500-700 degrees C, and the maximum synergy exhibits with a sawdust blending ratio of 0.6 at 600 degrees C. The gas product yields remarkably increase at lower temperature range by reducing tar yield. The CO yield increases up to 26% at 400 degrees C and CH(4) yield increases up to 62% at 600 degrees C compared with the calculated value from the additive model. (c) 2010 Elsevier Ltd. All rights reserved.

Explosive and pyrotechnic aging demonstration

NASA Technical Reports Server (NTRS)

Rouch, L. L., Jr.; Maycock, J. N.

1976-01-01

The survivability was experimentally verified of fine selected explosive and pyrotechnic propellant materials when subjected to sterilization, and prolonged exposure to space environments. This verification included thermal characterization, sterilization heat cycling, sublimation measurements, isothermal decomposition measurements, and accelerated aging at a preselected elevated temperature. Temperatures chosen for sublimation and isothermal decomposition measurements were those in which the decomposition processess occurring would be the same as those taking place in real-time aging. The elevated temperature selected (84 C) for accelerated aging was based upon the parameters calculated from the kinetic data obtained in the isothermal measurement tests and was such that one month of accelerated aging in the laboratory approximated one year of real-time aging at 66 C. Results indicate that HNS-IIA, pure PbN6, KDNBF, and Zr/KC10 are capable of withstanding sterilization. The accelerated aging tests indicated that unsterilized HNS-IIA and Zr/KC104 can withstand the 10 year, elevated temperature exposure, pure PbN6 and KDNBF exhibit small weight losses (less than 2 percent) and B/KC104 exhibits significant changes in its thermal characteristics. Accelerated aging tests after sterilization indicated that only HNS-IIA exhibited high stability.

Thermo-Oxidative Stability of Graphite/PMR-15 Composites: Effect of Fiber Surface Modification on Composite Shear Properties

NASA Technical Reports Server (NTRS)

Madhukar, Madhu S.; Bowles, Kenneth J.; Papadopolous, Demetrios S.

1994-01-01

Experiments were conducted to establish a correlation between the weight loss of a polyimide (PMR- 15) matrix and graphite fibers and the in-plane shear properties of their unidirectional composites subjected to different isothermal aging times up to 1000 hr at 316 C. The role of fiber surface treatment on the composite degradation during the thermo-oxidative aging was investigated by using A4 graphite fibers with three surface modifications: untreated (AU-4), surface treated (AS-4), and surface treated and sized with an epoxy-compatible sizing (AS-4G). The weight loss of the matrix fibers, and composites was determined during the aging. The effect of thermal aging was seen in all the fiber samples in terms of weight loss and reduction in fiber diameter. Calculated values of weight loss fluxes for different surfaces of rectangular unidirectional composite plates showed that the largest weight loss occurred at those cut surfaces where fibers were perpendicular to the surface. Consequently, the largest amount of damage was also noted on these cut surfaces. Optical observation of the neat matrix and composite plates subjected to different aging times revealed that the degradation (such as matrix microcracking and void growth) occurred in a thin surface layer near the specimen edges. The in-plane shear modulus of the composites was unaffected by the fiber surface treatment and the thermal aging. The shear strength of the composites with the untreated fibers was the lowest and it decreased with aging. A fracture surface examination of the composites with untreated fibers suggested that the weak interface allowed the oxidation reaction to proceed along the interface and thus expose the inner material to further oxidation. The results indicated that the fiber-matrix interface affected the composite degradation process during its thermal aging and that the the weak interface accelerated the composite degradation.

Long-Term Isothermal Aging Effects on Carbon Fabric-Reinforced PMR-15 Composites: Compression Strength

NASA Technical Reports Server (NTRS)

Bowles, Kenneth J.; Roberts, Gary D.; Kamvouris, John E.

1996-01-01

A study was conducted to determine the effects of long-term isothermal thermo-oxidative aging on the compressive properties of T-650-35 fabric reinforced PMR-15 composites. The temperatures that were studied were 204, 260, 288, 316, and 343 C. Specimens of different geometries were evaluated. Cut edge-to-surface ratios of 0.03 to 0.89 were fabricated and aged. Aging times extended to a period in excess of 15,000 hours for the lower temperature runs. The unaged and aged specimens were tested in compression in accordance with ASTM D-695. Both thin and thick (plasma) specimens were tested. Three specimens were tested at each time/temperature/geometry condition. The failure modes appeared to be initiated by fiber kinking with longitudinal, interlaminar splitting. In general, it appears that the thermo-oxidative degradation of the compression strength of the composite material may occur by both thermal (time-dependent) and oxidative (weight-loss) mechanisms. Both mechanisms appear to be specimen-thickness dependent.

Pyrolysis and oxy-fuel combustion characteristics and kinetics of petrochemical wastewater sludge using thermogravimetric analysis.

PubMed

Chen, Jianbiao; Mu, Lin; Cai, Jingcheng; Yao, Pikai; Song, Xigeng; Yin, Hongchao; Li, Aimin

2015-12-01

The pyrolysis and oxy-fuel combustion characteristics of petrochemical wastewater sludge (PS) were studied in air (O2/N2) and oxy-fuel (O2/CO2) atmospheres using non-isothermal thermogravimetric analysis (TGA). Pyrolysis experiments showed that the weight loss profiles were almost similar up to 1050K in both N2 and CO2 atmospheres, while further weight loss took place in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Compared with 20%O2/80%N2, the drying and devolatilization stage of PS were delayed in 20%O2/80%CO2 due to the differences in properties of the diluting gases. In oxy-fuel combustion experiments, with O2 concentration increasing, characteristic temperatures decreased, while characteristic combustion rates and combustion performance indexes increased. Kinetic analysis of PS decomposition under various atmospheres was performed using Coats-Redfern approach. The results indicated that, with O2 concentration increasing, the activation energies of Step 1 almost kept constant, while the values of subsequent three steps increased. Copyright © 2015 Elsevier Ltd. All rights reserved.

Isothermal aging effects on PMR-15 resin

NASA Technical Reports Server (NTRS)

Bowles, Kenneth J.; Jayne, Douglas; Leonhardt, Todd A.

1992-01-01

Specimens of PMR-15 polyimide neat resin were aged in air at temperatures of 288, 316, and 343 C. Weight losses and dimensional changes were monitored during the course of the exposure time. Physical changes were also observed by optical and electron microscopy. It was found that polyimide polymer degradation occurred within a thin surface layer that developed and grew during thermal aging. The cores of the polymer specimens were protected from oxidative degradation, and they were relatively unchanged by the thermal treatment. Surface cracking was observed at 343 C and was probably due to an interaction between voids and stresses that developed in the surface layer.

Protective coatings for high-temperature polymer matrix composites

NASA Technical Reports Server (NTRS)

Harding, David R.; Sutter, James K.; Papadopoulos, Demetrios S.

1993-01-01

Plasma-enhanced chemical vapor deposition was used to deposit silicon nitride on graphite-fiber-reinforced polyimide composites to protect against oxidation at elevated temperatures. The adhesion and integrity of the coating were evaluated by isothermal aging (371 C for 500 hr) and thermal cycling. The amorphous silicon nitride (a-SiN:H) coating could withstand stresses ranging from approximately 0.18 GPa (tensile) to -1.6 GPa (compressive) and provided a 30 to 80 percent reduction in oxidation-induced weight loss. The major factor influencing the effectiveness of a-SiN:H as a barrier coating against oxidation is the surface finish of the polymer composite.

Effect of geometry on thermal aging behavior of Celion/LARC-160 composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nelson, J.B.

1987-12-01

Laminates of Celion/LARC-160, fabricated in thicknesses from 4 to 16 ply and in unidirectional, x-ply and fabric ply configurations, were isothermally aged at temperatures of 204, 260 and 316 C for periods up to 15,000 hours. Weight-loss of the test panels was measured at selected intervals during aging. At the lower aging temperatures, it was observed that panel thickness and ply arrangement influenced the apparent stability: i.e., thicker panels degraded less than thin panels and unidirectional panels degraded less than x-ply or fabric reinforced panels. At higher aging temperatures, all panel configurations and thicknesses converged toward the same behavior.

Evaluating the Energy Recovery Potential of Nigerian Coals under Non-Isothermal Thermogravimetry

NASA Astrophysics Data System (ADS)

Bevan Nyakuma, Bemgba; Oladokun, Olagoke; Jauro, Aliyu; Damian Nyakuma, Denen

2017-07-01

This study investigated the fuel properties and energy recovery potential of two coal samples from Ihioma (IHM) and Ogboligbo (OGB) environs in Nigeria. The ultimate, proximate, and bomb calorimetric analyses of the coal were examined. Next, the rank classification and potential application of the coals were evaluated according to the ASTM standard D388. Lastly, thermal decomposition behaviour was examined by non-isothermal thermogravimetry (TG) under pyrolysis conditions from 30 - 900 °C. The results indicated IHM and OGB contain high proportions of combustible elements for potential thermal conversion. The higher heating value (HHV) of IHM was 20.37 MJ/kg whereas OGB was 16.33 MJ/kg. TG analysis revealed 55% weight loss for OGB and 76% for IHM. The residual mass was 23% for IHM and 44% for OGB. Based on the temperature profile characteristics (TPCs); Ton , Tmax , and Toff , IHM was more reactive than OGB due to its higher volatile matter (VM). Overall, results revealed the coals are Lignite (Brown) low-rank coals (LRCs) with potential for electric power generation.

Investigation on Adsorption and the Corrosion Inhibition Effect of Some Novel Hydrazide Derivatives for Mild Steel in HCl Solution

NASA Astrophysics Data System (ADS)

Singh, Dharmendra Kumar; Behera, Debasis; Singh, Mantu Kumar; Udayabhanu, G.; John, Rohith P.

2017-10-01

Two hydrazide derivatives, namely, N'-(thiophene-2-ylmethylene)nicotinic hydrazone (TNH) and N'-(pyrrol-2-ylmethylene)nicotinic hydrazone (PNH), have been synthesized and investigated as corrosion inhibitors for mild steel in 1 M HCl solution by electrochemical, weight loss, field emission-scanning electron microscope (FE-SEM), atomic force microscope (AFM), and quantum chemical calculation methods. The experimental results show that both the compounds are good inhibitors for mild steel in 1 M HCl. They act as mixed type inhibitors with predominating cathodic character. The adsorption of inhibitors obeys the Langmuir adsorption isotherm. Correlation between quantum chemical parameters and experimental results is discussed.

Solid-state reaction kinetics of neodymium doped magnesium hydrogen phosphate system

NASA Astrophysics Data System (ADS)

Gupta, Rashmi; Slathia, Goldy; Bamzai, K. K.

2018-05-01

Neodymium doped magnesium hydrogen phosphate (NdMHP) crystals were grown by using gel encapsulation technique. Structural characterization of the grown crystals has been carried out by single crystal X-ray diffraction (XRD) and it revealed that NdMHP crystals crystallize in orthorhombic crystal system with space group Pbca. Kinetics of the decomposition of the grown crystals has been studied by non-isothermal analysis. The estimation of decomposition temperatures and weight loss has been made from the thermogravimetric/differential thermo analytical (TG/DTA) in conjuncture with DSC studies. The various steps involved in the thermal decomposition of the material have been analysed using Horowitz-Metzger, Coats-Redfern and Piloyan-Novikova equations for evaluating various kinetic parameters.

Nonmetallic materials handbook. Volume 2: Epoxy and silicone materials

NASA Technical Reports Server (NTRS)

Podlaseck, S. E.

1982-01-01

Chemical and physical property test data obtained during qualification and receiving inspection testing of nonmetallic materials for the Viking Mars Lander program is presented. Thermochemical data showing degradation as a function of temperature from room temperature through 773 K is included. These data include activation energies for thermal degradation, rate constants, and exo- and/or endotherms. Thermal degradations carried out under vacuum include mass spectral data taken simultaneously during the decomposition. Many materials have supporting data such as condensation rates of degassed products and isothermal weight loss. Changes in mechanical, electrical, and thermal properties after exposure to 408 K in nitrogen for times ranging from 380 to 570 hours are included for many materials.

Analysis of the Barrier Properties of Polyimide-Silicate Nanocomposites

NASA Technical Reports Server (NTRS)

Campbell, Sandi; Johnston, J. Chris; Inghram, Linda; McCorkle, Linda; Silverman, Edward

2003-01-01

Montmorillonite clay was organically modified and dispersed into a thermoplastic (BPADA-BAPP) and a thermosetting (PMR-15) polyimide matrix. The barrier properties of the neat resins and the nanocomposites were evaluated. Reductions in gas permeability and water absorption were observed in thermoplastic polyimide nanocomposites. The thermosetting polyimide showed a reduction in weight loss during isothermal aging at 288 C. Carbon fabric (T650-35, 8 HS, 8 ply) composites were prepared using both the BPADE-BAPP and PMR-15 based nanocomposites. Dispersion of the layered silicate in the BPADA-BAPP matrix reduced helium permeability by up to 70 percent. The PMR-15/ silicate nanocomposite matrix had an increase in thermal oxidative stability of up to 25 percent.

The rate of chemical weathering of pyrite on the surface of Venus

NASA Technical Reports Server (NTRS)

Fegley, B., Jr.; Lodders, K.

1993-01-01

This abstract reports results of an experimental study of the chemical weathering of pyrite (FeS2) under Venus-like conditions. This work, which extends the earlier study by Fegley and Treiman, is part of a long range research program to experimentally measure the rates of thermochemical gas-solid reactions important in the atmospheric-lithospheric sulfur cycle on Venus. The objectives of this research are (1) to measure the kinetics of thermochemical gas-solid reactions responsible for both the production (e.g., anhydrite formation) and destruction (e.g., pyrrhotite oxidation) of sulfur-bearing minerals on the surface of Venus and (2) to incorporate these and other constraints into holistic models of the chemical interactions between the atmosphere and surface of Venus. Experiments were done with single crystal cubes of natural pyrite (Navajun, Logrono, Spain) that were cut and polished into slices of known weight and surface area. The slices were isothermally heated at atmospheric pressure in 99.99 percent CO2 (Coleman Instrument Grade) at either 412 C (685 K) or 465 C (738 K) for time periods up to 10 days. These two isotherms correspond to temperatures at about 6 km and 0 km altitude, respectively, on Venus. The reaction rate was determined by measuring the weight loss of the reacted slices after removal from the furnace. The reaction products were characterized by X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy on the SEM.

Development of primer sets for loop-mediated isothermal amplification that enables rapid and specific detection of Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae

USDA-ARS?s Scientific Manuscript database

Streptococcus dysgalactiae, Streptococcus uberis and Streptococcus agalactiae are the three main pathogens causing bovine mastitis, with great losses to the dairy industry. Rapid and specific loop-mediated isothermal amplification methods (LAMP) for identification and differentiation of these three ...

Oxidation of TD nickel at 1050 C and 1200 C as compared with three grades of nickel of different purity

NASA Technical Reports Server (NTRS)

Lowell, C. E.; Grisaffe, S. J.; Deadmore, D. L.

1972-01-01

The isothermal oxidation of three nickels of different purity, Ni-200, Ni-270, and JM-Ni, was compared with that of TD-Ni in air at 1050 and 1200 C. The samples were oxidized as ground, as polished, or as annealed and polished. Weight change, metal loss, scale thickness, oxide morphology, and scale texture were determined. In degree of oxidation, TD-Ni was nearly the same as the higher purity materials, Ni-270 and JM-Ni; and less pure Ni-200 oxidized more than the others. However, in microstructure and scale texture the TD-Ni more closely resembled Ni-200. Grinding only charged the texture of the oxides of Ni_200 and TD-Ni.

Radiative modelling by the zonal method and WSGG model in inhomogeneous axisymmetric cylindrical enclosure

NASA Astrophysics Data System (ADS)

Méchi, Rachid; Farhat, Habib; Said, Rachid

2016-01-01

Nongray radiation calculations are carried out for a case problem available in the literature. The problem is a non-isothermal and inhomogeneous CO2-H2O- N2 gas mixture confined within an axisymmetric cylindrical furnace. The numerical procedure is based on the zonal method associated with the weighted sum of gray gases (WSGG) model. The effect of the wall emissivity on the heat flux losses is discussed. It is shown that this property affects strongly the furnace efficiency and that the most important heat fluxes are those leaving through the circumferential boundary. The numerical procedure adopted in this work is found to be effective and may be relied on to simulate coupled turbulent combustion-radiation in fired furnaces.

Study of the effects of heat-treatment of hydroxyapatite synthesized in gelatin matrix

NASA Astrophysics Data System (ADS)

Zaits, A. V.; Golovanova, O. A.; Kuimova, M. V.

2017-01-01

In the study, the isothermal thermogravimetric analysis (TGA) of hydroxyapatite synthesized in gelatin matrix (HAG) has been performed. 3 wt.% HAG samples were synthesized from the solution simulating the human extracellular fluid (SBF). X-ray diffraction and IR spectroscopy were used to determine the composition. During the experiment, increase in the calcination temperature up to 200°C-800°C was found to cause weight loss. The study of phase composition revealed that heat treatment does not affect the phase composition of the solid phase, which is composed of hydroxylapatite (HA). The prepared HAG (3 wt.% gelatin) samples are shown to have low thermal stability; the degradation of the samples occurs at 400° C.

Study of the effects of heat-treatment of hydroxyapatite synthesized in gelatin matrix

NASA Astrophysics Data System (ADS)

Zaits, A. V.; Golovanova, O. A.; Kuimova, M. V.

2017-01-01

In the study, the isothermal thermogravimetric analysis (TGA) of hydroxyapatite synthesized in gelatin matrix (HAG) has been performed. 3 wt.% HAG samples were synthesized from the solution simulating the human extracellular fluid (SBF). X-ray diffraction and IR spectroscopy were used to determine the composition. During the experiment, increase in the calcination temperature up to 200°C-800°C was found to cause weight loss. The study of phase composition revealed that heat treatment does not affect the phase composition of the solid phase, which is composed of hydroxylapatite (HA). The prepared HAG (3 wt.% gelatin) samples are shown to have low thermal stability; the degradation of the samples occurs at 400°C.

Corrosion inhibition of aminated hydroxyl ethyl cellulose on mild steel in acidic condition.

PubMed

Sangeetha, Y; Meenakshi, S; Sairam Sundaram, C

2016-10-05

Aminated hydroxyethyl cellulose (AHEC) was synthesized, characterized using Fourier Transform Infrared spectroscopy (FTIR) and the corrosion inhibition of AHEC on mild steel in 1M HCl was studied using chemical and electrochemical studies. Results obtained in weight loss method showed that inhibition efficiency increased with increase in concentration of AHEC. The adsorption of the inhibitor on metal surface followed Frumkin isotherm. Polarization studies revealed that the AHEC inhibits through mixed mode. Thermodynamic parameters and activation energy were calculated and discussed. FTIR and X-ray diffraction studies (XRD) confirmed the adsorption of the inhibitor. The surface morphology was studied using Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM). Copyright © 2016 Elsevier Ltd. All rights reserved.

Flame retardant polyphosphazenes

NASA Technical Reports Server (NTRS)

Paciorek, K. L.; Karle, D. W.; Kratzer, R. H.

1973-01-01

Six polyphosphazene compositions were prepared by reaction of three bis-tertiary phosphines with two phenyl-s-triazine derived diazides. All six polyphosphazenes produced were completely characterized, four of them were furthermore subjected to isothermal gravimetric analysis, smoke density measurements, flammability and oxidative thermal degradation testing. The results of the characterization studies indicate that only low molecular weight oligomers, possibly of a cyclic structure, were obtained in the polymerization reactions. Despite this, however, two of the materials showed no weight loss after 96 hr at 200 C, one did not autoignite at 500 C in air, and all four self extinguished when exposed to a flame as soon as contact between flame and resin was lost. The only toxic decomposition products to be concerned about were found to be hydrogen cyanide and benzene. Under the conditions employed it was proven, however, that the quantities of toxic products are greatly reduced if no ignition takes place, e.g., if thermal decomposition proceeds at a sufficiently low rate.

Influence of chain microstructure on thermodegradative behavior of furfuryl methacrylate-N-vinylpyrrolidone random copolymers by thermogravimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peniche, C.; Zaldivar, D.; Bulay, A.

1993-12-20

The thermal behavior of random copolymers of furfuryl methacrylate (F) and N-vinyl-pyrrolidone (P) was studied by means of dynamic thermogravimetric analysis (TGA) in the range 100--600 C. The dynamic experiments show that these copolymers exhibit two degradation steps in the intervals 260--320 C and 350--520 C, respectively. The normalized weight loss in the low temperature interval increases as the mole fraction of F in the copolymer m[sub F] increases, whereas an inverted trend in the high temperature interval is observed. The apparent activation energy E[sub a] of the first degradation step for copolymers prepared with different composition, was obtained accordingmore » to the treatment suggested by Broido. A plot of the values of E[sub a] versus the F dead molar fraction in the copolymer chains m[sub FF] gave a straight line that indicates that there is a direct relationship between the thermogravimetric behavior of these systems and their corresponding microstructure, that is, the distribution of comonomeric units along the copolymers chains. The first decomposition step was also studied by isothermal TGA and a good linearity for the variation of the weight loss percentage [Delta]W versus m[sub F] at least during the first 30 min of treatment was obtained.« less

Production of Nanocrystalline Ni-20Cr Coatings for High-Temperature Applications

NASA Astrophysics Data System (ADS)

Kumar, Manoj; Singh, Harpreet; Singh, Narinder

2014-04-01

Presynthesized nanocrystalline Ni-20Cr powder was deposited on SA 516 and T91 boiler steels by a high-velocity oxy-fuel spraying process. Ni-20Cr powder was synthesized by the ball milling approach. The high-temperature oxidation behavior of bare and coated samples was then studied under cyclic isothermal conditions at 900 °C for 50 cycles. The kinetics of oxidation was established using weight change measurements for the bare and coated boiler steels. Uncoated and coated samples of T91 steel were exposed to the superheated zone of a power plant boiler at 750 °C under cyclic conditions for 15 cycles. Each cycle consisted of 100 h of heating followed by 1 h of cooling. Attempts were made to study the kinetics of erosion-corrosion using weight change and thickness loss data for the samples. Different characterization techniques were used to study the oxidized and eroded-corroded samples, including x-ray diffraction, scanning electron microscopy/energy-dispersive spectroscopy, and x-ray mapping analyses. The Ni-20Cr alloy powder coating was found to offer excellent oxidation resistance to the base steels and was successful in reducing the weight gain of SA 516 steel by 98.5 % and that of T91 steel by 65 %. The coating was observed to reduce the erosion-corrosion rate of T91 steel by 86 % in terms of thickness loss. This indicates that the investigated nanostructured coating can be a better choice over conventional coating for erosion-corrosion control of boiler tubes.

Thermal barrier coating life and isothermal oxidation of low-pressure plasma-sprayed bond coat alloys

NASA Technical Reports Server (NTRS)

Brindley, W. J.; Miller, R. A.

1990-01-01

The paper investigates the isothermal oxidation kinetics of Ni-35Cr-6Al-0.95Y, Ni-18Cr-12Al-0.3Y, and Ni-16Cr-6Al-0.3Y low-pressure plasma-sprayed bond coat alloys and examines the effect of these alloys on the thermal barrier coating (TBC) cyclic life. TBC life was examined by cycling substrates coated with the different bond coats and a ZrO2-7 wt pct Y2O3 TBC in an air-rich burner rig flame between 1150 C and room temperature. The oxidation kinetics of the three bond coat alloys was examined by isothermal oxidation of monolithic NJiCrAlY coupons at 1083 C. The Ni-35Cr-6Al-0.95Y alloy exhibits comparatively high isothermal oxidation weight gains and provides the longest TBC life, whereas the Ni-16Cr-6Al-0.3Y alloy had the lowest weight gains and provided the shortest TBC life. The results show that, although bond coat oxidation is known to have a strong detrimental effect on TBC life, it is not the only bond coat factor that determines TBC life.

Rheological study of the effect of polyethylene oxide (PEO) homopolymer on the gelation of PEO-PPO-PEO triblock copolymer in aqueous solution

NASA Astrophysics Data System (ADS)

Li, Xiaolei; Hyun, Kyu

2018-05-01

The effects of polyethylene oxide (PEO) homopolymer on the gelation behavior of a PEO100-PPO65-PEO100 triblock copolymer (Pluronic F127) were explored in aqueous solution under non-isothermal and isothermal conditions. Under non-isothermal conditions (temperature sweep test), two transition points were observed on increasing temperature, that is, at lower and upper gelation temperatures (LTgel and UTgel, respectively). Between LTgel and UTgel, F127 aqueous solutions maintained a hard gel state. Both molecular weight (MW) and PEO concentration affected these two gelation temperatures. In particular, relative molecular weight (MWrel ≡ molecular weight of PEO homopolymer/PEO segment of F127) affected LTgel. LTgel decreased on increasing PEO concentration at MWrel values of <1, but increased on increasing PEO concentration at MWrel values of >1. On the other hand, UTgel decreased with increasing PEO concentration regardless of MWrel. Under isothermal conditions (fixed temperature between LTgel and UTgel), the effects of PEO homopolymer on the mechanical properties of F127 hard gel were systemically investigated using small and large amplitude oscillatory shear tests. In the linear viscoelastic regime, total intra-cycle stress and elastic intra-cycle stress were similar, and viscous response increased on increasing PEO concentration. However, at large strain amplitudes, hard gels showed intra-cycle stiffening but inter-cycle softening behavior. In addition, on increasing PEO concentrations, viscous nonlinearities underwent strain-rate thickening followed by strain-rate thinning.

Studies on the Inhibition of Mild Steel Corrosion by Rauvolfia serpentina in Acid Media

NASA Astrophysics Data System (ADS)

Bothi Raja, P.; Sethuraman, M. G.

2010-07-01

Alkaloid extract of Rauvolfia serpentina was tested as corrosion inhibitor for mild steel in 1 M HCl and H2SO4 using weight loss method at three different temperatures, viz., 303, 313, and 323 K, potentiodynamic polarization, electrochemical impedance spectroscopy and scanning electron microscope (SEM) studies. It is evident from the results of this study that R. serpentina effectively inhibits the corrosion in both the acids through adsorption process following Tempkin adsorption isotherm. The protection efficiency increased with increase in inhibitor concentration and temperature. Free energy of adsorption calculated from the temperature studies also revealed the chemisorption. The mixed mode of action exhibited by the inhibitor was confirmed by the polarization studies while SEM analysis substantiated the formation of protective layer over the mild steel surface.

Kinetics of Corrosion Inhibition of Aluminum in Acidic Media by Water-Soluble Natural Polymeric Pectates as Anionic Polyelectrolyte Inhibitors.

PubMed

Hassan, Refat M; Zaafarany, Ishaq A

2013-06-17

Corrosion inhibition of aluminum (Al) in hydrochloric acid by anionic polyeletrolyte pectates (PEC) as a water-soluble natural polymer polysaccharide has been studied using both gasometric and weight loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing inhibitor concentration and decrease with increasing temperature. The inhibition action of PEC on Al metal surface was found to obey the Freundlich isotherm. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the kinetic results is discussed in the paper.

Kinetics of Corrosion Inhibition of Aluminum in Acidic Media by Water-Soluble Natural Polymeric Pectates as Anionic Polyelectrolyte Inhibitors

PubMed Central

Hassan, Refat M.; Zaafarany, Ishaq A.

2013-01-01

Corrosion inhibition of aluminum (Al) in hydrochloric acid by anionic polyeletrolyte pectates (PEC) as a water-soluble natural polymer polysaccharide has been studied using both gasometric and weight loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing inhibitor concentration and decrease with increasing temperature. The inhibition action of PEC on Al metal surface was found to obey the Freundlich isotherm. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the kinetic results is discussed in the paper. PMID:28809282

Analysis of the variation of the 0°C isothermal altitude during rainfall events

NASA Astrophysics Data System (ADS)

Zeimetz, Fränz; Garcìa, Javier; Schaefli, Bettina; Schleiss, Anton J.

2016-04-01

In numerous countries of the world (USA, Canada, Sweden, Switzerland,…), the dam safety verifications for extreme floods are realized by referring to the so called Probable Maximum Flood (PMF). According to the World Meteorological Organization (WMO), this PMF is determined based on the PMP (Probable Maximum Precipitation). The PMF estimation is performed with a hydrological simulation model by routing the PMP. The PMP-PMF simulation is normally event based; therefore, if no further information is known, the simulation needs assumptions concerning the initial soil conditions such as saturation or snow cover. In addition, temperature series are also of interest for the PMP-PMF simulations. Temperature values can not only be deduced from temperature measurement but also using the temperature gradient method, the 0°C isothermal altitude can lead to temperature estimations on the ground. For practitioners, the usage of the isothermal altitude for referring to temperature is convenient and simpler because one value can give information over a large region under the assumption of a certain temperature gradient. The analysis of the evolution of the 0°C isothermal altitude during rainfall events is aimed here and based on meteorological soundings from the two sounding stations Payerne (CH) and Milan (I). Furthermore, hourly rainfall and temperature data are available from 110 pluviometers spread over the Swiss territory. The analysis of the evolution of the 0°C isothermal altitude is undertaken for different precipitation durations based on the meteorological measurements mentioned above. The results show that on average, the isothermal altitude tends to decrease during the rainfall events and that a correlation between the duration of the altitude loss and the duration of the rainfall exists. A significant difference in altitude loss is appearing when the soundings from Payerne and Milan are compared.

Corrosion inhibition of Q235 steel in 1 M HCl using quaternized tetraaniline as a corrosion inhibitor

NASA Astrophysics Data System (ADS)

Li, Xiangyu; Ye, Yuwei; Liu, Tong; Zheng, Wenru; Yang, Feng; Zhao, Haichao; Wang, Liping

2017-12-01

Novel quaternary ammonium cation containing tetraaniline (QATA) was successfully synthesized by condensation of amine-capped tetraaniline with 6-bromohexanoic acid, followed by quaternarization with triethylamine. The corrosion inhibition performance of QATA with their adsorption mechanisms for Q235 steel was studied in 1 M HCl solution by a series of methods such as weight loss measurements, potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and atomic force microscopy (AFM). The inhibition efficiency (IE%) increased with increasing concentrations of QATA, reaching a value up to 97.47% at a concentration of 150 mg l-1. Potentiodynamic polarization curves showed that the QATA affected both cathodic and anodic protection and was a mixed type inhibitor in 1 M HCl corrosive medium. Adsorption isotherm studies confirmed that the absorption of QATA on the Q235 steel surface in 1 M HCl solution obeyed Langmuir adsorption isotherm, and the adsorption process of corrosion inhibition on Q235 steel surface involved both the physical and chemical adsorption. The EDS analysis determined the adsorption of QATA molecules on the steel surface, the surface morphologies before and after immersion in 1 M HCl medium were also investigated by SEM and AFM.

Effect of degree of deacetylation of chitosan on adsorption capacity and reusability of chitosan/polyvinyl alcohol/TiO2 nano composite.

PubMed

Habiba, Umma; Joo, Tan Chin; Siddique, Tawsif A; Salleh, Areisman; Ang, Bee Chin; Afifi, Amalina M

2017-11-01

The chitosan/polyvinyl alcohol/TiO 2 composite was synthesized. Two different degrees of deacetylation of chitosan were prepared by hydrolysis to compare the effectiveness of them. The composite was analyzed via field emission scanning electron microscopy, Fourier transform infrared, X-ray diffraction, thermal gravimetric analysis, weight loss test and adsorption study. The FTIR and XRD results proved the interaction among chitosan, PVA and TiO 2 without any chemical reaction. It was found that, chitosan with higher degree of deacetylation has better stability. Furthermore, it also showed that higher DD of chitosan required less time to reach equilibrium for methyl orange. The adsorption followed the pseudo-second-order kinetic model. The Langmuir and Freundlich isotherm models were fitted well for isotherm study. Adsorption capacity was higher for the composite containing chitosan with higher DD. The dye removal rate was independent of the dye's initial concentration. The adsorption capacity was increased with temperature and it was found from reusability test that the composite containing chitosan with higher DD is more reusable. It was notable that adsorption capacity was even after 15 runs. Therefore, chitosan/PVA/TiO 2 composite can be a very useful material for dye removal. Copyright © 2017 Elsevier B.V. All rights reserved.

Theoretical study of the accuracy of the elution by characteristic points method for bi-langmuir isotherms.

PubMed

Ravald, L; Fornstedt, T

2001-01-26

The bi-Langmuir equation has recently been proven essential to describe chiral chromatographic surfaces and we therefore investigated the accuracy of the elution by characteristic points method (ECP) for estimation of bi-Langmuir isotherm parameters. The ECP calculations was done on elution profiles generated by the equilibrium-dispersive model of chromatography for five different sets of bi-Langmuir parameters. The ECP method generates two different errors; (i) the error of the ECP calculated isotherm and (ii) the model error of the fitting to the ECP isotherm. Both errors decreased with increasing column efficiency. Moreover, the model error was strongly affected by the weight of the bi-Langmuir function fitted. For some bi-Langmuir compositions the error of the ECP calculated isotherm is too large even at high column efficiencies. Guidelines will be given on surface types to be avoided and on column efficiencies and loading factors required for adequate parameter estimations with ECP.

Sorption equilibrium of mercury onto ground-up tree fern.

PubMed

Ho, Yuh-Shan; Wang, Chung-Chi

2008-08-15

The sorption behavior of mercury at different temperatures onto ground-up tree fern was investigated. The experimental results were fitted to two two-parameter isotherms, the Freundlich and Langmuir isotherms, as well as to two three-parameter isotherms, the Redlich-Peterson and Sips isotherms to obtain the characteristic parameters of each model. A comparison of best-fitting was performed using the coefficient of determination and Chi-square test. Both the Langmuir and Redlich-Peterson isotherms were found to well represent the measured sorption data. According to the evaluation using the Langmuir equation, the saturated monolayer sorption capacity of mercury ions onto ground-up tree fern was 26.5 mg/g at 298 K. It was noted that an increase in temperature resulted in a higher mercury ion loading per unit weight of the tree fern. In addition, various thermodynamic parameters, such as DeltaG degrees, DeltaH degrees, and DeltaS degrees, were calculated and compared with the sorption of mercury by other sorbents.

Efficiency for unretained solutes in packed column supercritical fluid chromatography. I. Theory for isothermal conditions and correction factors for carbon dioxide.

PubMed

Poe, Donald P

2005-06-17

A general theory for efficiency of nonuniform columns with compressible mobile phase fluids is applied to the elution of an unretained solute in packed-column supercritical fluid chromatography (pSFC). The theoretical apparent plate height under isothermal conditions is given by the Knox equation multiplied by a compressibility correction factor f1, which is equal to the ratio of the temporal-to-spatial average densities of the mobile phase. If isothermal conditions are maintained, large pressure drops in pSFC should not result in excessive efficiency losses for elution of unretained solutes.

Comparison Between Dielectric Barrier Discharge Plasma and Ozone Regenerations of Activated Carbon Exhausted with Pentachlorophenol

NASA Astrophysics Data System (ADS)

Qu, Guangzhou; Liang, Dongli; Qu, Dong; Huang, Yimei; Li, Jie

2014-06-01

In this study, two regeneration methods (dielectric barrier discharge (DBD) plasma and ozone (O3) regeneration) of saturated granular activated carbon (GAC) with pentachlorophenol (PCP) were compared. The results show that the two regeneration methods can eliminate contaminants from GAC and recover its adsorption properties to some extent. Comparing the DBD plasma with O3 regeneration, the adsorption rate and the capacity of the GAC samples after DBD plasma regeneration are greater than those after O3 regeneration. O3 regeneration decreases the specific surface area of GAC and increases the acidic surface oxygen groups on the surface of GAC, which causes a decrease in PCP on GAC uptake. With increasing regeneration cycles, the regeneration efficiencies of the two methods decrease, but the decrease in the regeneration efficiencies of GAC after O3 regeneration is very obvious compared with that after DBD plasma regeneration. Furthermore, the equilibrium data were fitted by the Freundlich and Langmuir models using the non-linear regression technique, and all the adsorption equilibrium isotherms fit the Langmuir model fairly well, which demonstrates that the DBD plasma and ozone regeneration processes do not appear to modify the adsorption process, but to shift the equilibrium towards lower adsorption concentrations. Analyses of the weight loss of GAC show that O3 regeneration has a lower weight loss than DBD plasma regeneration.

Comparison of isothermal and cyclic oxidation behavior of twenty-five commercial sheet alloys at 1150 C

NASA Technical Reports Server (NTRS)

Barrett, C. A.; Lowell, C. E.

1975-01-01

Twenty-five commercial nickel-, iron-, and cobalt-base sheet alloys incorporating chromium or chromium and aluminum additions for oxidation resistance were tested at 1150 C in air for 100 hr in both isothermal and 1-hr cyclic furnace exposures. The alloys were evaluated by sample specific weight change, by type of scale formed, by amount and type of spall, and by sample thickness change and microstructure.-

Thermal degradation of the tensile properties of undirectionally reinforced FP-AI203/EZ 33 magnesium composites

NASA Technical Reports Server (NTRS)

Bhatt, R. T.; Grimes, H. H.

1982-01-01

The effects of isothermal and cyclic exposure on the room temperature axial and transverse tensile strength and dynamic flexural modulus of 35 volume percent and 55 volume percent FP-Al2O3/EZ 33 magnesium composites were studied. The composite specimens were continuously heated in a sand bath maintained at 350 C for up to 150 hours or thermally cycled between 50 and 250 C or 50 and 350 C for up to 3000 cycles. Each thermal cycle lasted for a total of six minutes with a hold time of two minutes at the maximum temperature. Results indicate to significant loss in the room temperature axial tensile strength and dynamic flexural modulus of composites thermally cycled between 50 and 250 C or of composites isothermally heated at 350 C for up to 150 hours from the strength and modulus data for the untreated, as fabricated composites. In contrast, thermal cycling between 50 and 350 C caused considerable loss in both room temperature strength and modulus. Fractographic analysis and measurement of composite transverse strength and matrix hardness of thermally cycled and isothermally heated composites indicated matrix softening and fiber/matrix debonding due to void growth at the interface and matrix cracking as the likely causes of the strength and modulus loss behavior.

Oxidation Kinetics of Cast TiAl3

NASA Technical Reports Server (NTRS)

Smialek, J. L.; Humphrey, D. L.

1992-01-01

The isothermal oxidation kinetics of the TiAl3 compound over a wide temperature range is documented, and these rates are related to exclusive alpha-Al2O3 scale growth. The specific weight change vs time curves are shown. Two abnormalities are immediately apparent. One is that a rapid initial uptake of oxygen occurs at times less than 5 h, followed by a lower oxidation rate at longer times, for tests at 900 C and below. The other is that the final weight changes for the 700, 800, and 900 C tests are not in the sequence expected with respect to temperature. Isothermal oxidation of drop cast TiAl above 1000 C was found to exhibit parabolic oxidation controlled by protective alpha-Al2O3 scale formation. TiAl is the only phase in the binary Ti-Al system that forms exclusive scales of alpha-Al2O3 in isothermal oxidation. High anomalous rates at short times and at temperatures below 1000 C resulted from the internal oxidation of a second phase of aluminum.

Effects of thermal and environmental exposure on the mechanical properties of graphite/polyimide composites

NASA Technical Reports Server (NTRS)

Hanson, M. P.; Serafini, T. T.

1971-01-01

Composites were exposed in circulating and static air environments up to 589 K for a maximum of 1000 hours. Composites of HT-S, HM-S, Thornel 50S, and Fortafil 5-Y fiber and a new addition type polyimide resin were laminated in a matched-die mold. Flexural strengths, flexural modulus, and interlaminar shear strengths were determined at 297, 533, and 598 K after various durations of exposure. Composite and fiber weight loss characteristics were determined by isothermal gravimetric analysis in air. Properties of composites exposed and tested at the environment temperatures were compared with those determined under short-term exposure. A new short beam interlaminar shear fixture is described. Environmental effects of long-term ambient temperature exposure on the elevated temperature mechanical properties of graphite/polyimide composites are presented.

Inhibiting effects of some oxadiazole derivatives on the corrosion of mild steel in perchloric acid solution

NASA Astrophysics Data System (ADS)

Lebrini, Mounim; Bentiss, Fouad; Vezin, Hervé; Lagrenée, Michel

2005-11-01

The efficiency of 3,5-bis( n-pyridyl)-1,3,4-oxadiazole ( n-POX, n = 1, 2, 3), as corrosion inhibitors for mild steel in 1 M perchloric acid (HClO 4) have been determined by weight loss measurements and electrochemical studies. The results show that these inhibitors revealed a good corrosion inhibition even at very low concentrations. Comparison of results among those obtained by the studied oxadiazoles shows that 3-POX was the best inhibitor. Polarisation curves indicate that n-pyridyl substituted-1,3,4-oxadiazoles are mixed type inhibitors in 1 M HClO 4. The adsorption of these inhibitors follows a Langmuir isotherm model. The electronic properties of n-POX, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR).

Kinetics of corrosion inhibition of aluminum in acidic media by water-soluble natural polymeric chondroitin-4-sulfate as anionic polyelectrolyte inhibitor.

PubMed

Hassan, Refat M; Ibrahim, Samia M; Takagi, Hideo D; Sayed, Suzan A

2018-07-15

Corrosion inhibition of aluminum (Al) in hydrochloric acid by anionic polyelectrolyte chondroitin-4-sulfate (CS) polysaccharide has been studied using both gasometrical and weight-loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing the inhibitor concentration and decreased with increasing temperature. The inhibition action of CS on Al metal surface was found to obey both of Langmuir and Freundlich isotherms. The factors affecting the corrosion rates such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and the temperature were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the results obtained is discussed. Copyright © 2018. Published by Elsevier Ltd.

Simultaneous removal of potent cyanotoxins from water using magnetophoretic nanoparticle of polypyrrole: adsorption kinetic and isotherm study.

PubMed

Hena, S; Rozi, R; Tabassum, S; Huda, A

2016-08-01

Cyanotoxins, microcystins and cylindrospermopsin, are potent toxins produced by cyanobacteria in potable water supplies. This study investigated the removal of cyanotoxins from aqueous media by magnetophoretic nanoparticle of polypyrrole adsorbent. The adsorption process was pH dependent with maximum adsorption occurring at pH 7 for microcystin-LA, LR, and YR and at pH 9 for microcystin-RR and cylindrospermopsin (CYN). Kinetic studies and adsorption isotherms reflected better fit for pseudo-second-order rate and Langmuir isotherm model, respectively. Thermodynamic calculations showed that the cyanotoxin adsorption process is endothermic and spontaneous in nature. The regenerated adsorbent can be successfully reused without appreciable loss of its original capacity.

Effect of polypyrrole embedment on non-isothermal crystallization kinetics of poly (vinylidene fluoride-co-hexafluoropropylene)

NASA Astrophysics Data System (ADS)

Biswas, Swarup; Bhattacharya, S.

2017-05-01

Polypyrrole (PPy)/Poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) blend is synthesized by in situ polymerization of pyrrole. FTIR confirms the formation of Polypyrrole (PPy) within PVDF-HFP matrices. Weight percentages of different components within composites are estimated by TGA. Detailed study of nucleation and kinetics at its melt condition under non-isothermal environment is done by the DSC measurement. The presence of PPy within the PVDF-HFP matrices accelerated the nucleation rate of the polymer.

Effect of modified atmosphere packaging and temperature abuse on flavor related volatile compounds of rocket leaves (Diplotaxis tenuifolia L.).

PubMed

Mastrandrea, Leonarda; Amodio, Maria Luisa; Pati, Sandra; Colelli, Giancarlo

2017-07-01

The effect of storage conditions on flavor-related volatile composition of wild rocket ( Diplotaxis tenuifolia ) was investigated on Modified Atmosphere packed (MAP) leaves stored under isothermal and non-isothermal conditions. In a first experiment the effect of MAP was compared to the storage in air at 5 °C; a second experiment aimed to study the effect of non isothermal conditions, with two temperature abuses (at 13 °C for 24 h) during a 5 °C. Twenty-four volatiles were detected, including C6, C5, isothiocyanate, lipid-derived and sulfur compounds. In the first experiment, MAP-stored rocket showed a slower loss of typical flavour volatiles (thiocyanates and isothiocyanates) and a slower production of off-flavors until 6 days of storage, compared to leaves stored in air. After this time, dimethyl sulfide and acetaldehyde dramatically increased in MAP-stored rocket samples. In the second experiment, samples stored under non-isothermal conditions showed lower O 2 and higher CO 2 concentrations than samples stored under isothermal conditions. Rocket leaves stored under non-isothermal conditions showed an increased production of volatiles responsible of off-flavors (acetaldehyde and dimethyl sulfide) following temperature abuse comparing to storage in isothermal condition. Thus, dimethyl sulfide and acetaldehyde could be effective markers for tracking the effect of temperature fluctuations on rocket during storage.

Teammates and social influence affect weight loss outcomes in a team-based weight loss competition

PubMed Central

Leahey, Tricia M.; Kumar, Rajiv; Weinberg, Brad M.; Wing, Rena R.

2013-01-01

Team-based Internet interventions are increasing in popularity as a way of promoting weight loss in large numbers of individuals. Given that social networks influence health behavior change, this study investigated the effects of teammates and social influence on individual weight loss during a team-based weight loss competition. Shape Up Rhode Island 2009 was a 12-week online program open to adult residents of Rhode Island. Participants joined with a team and competed with other teams on weight loss and/or physical activity. OW/OB individuals (N=3,330; 76%female; age=46.1±10.8; BMI=31.2±5.3kg/m2), representing 987 teams, completed the weight loss program. Multilevel modeling was used to examine whether weight loss clustered among teammates and whether percentage of teammates in the weight loss division and reported teammate influence on weight loss were associated with individual weight outcomes. OW/OB completers reported losing 4.2±3.4% of initial body weight. Weight loss was similar among teammates (ICC=.10, p<.001). Moreover, having a greater percentage of teammates in the weight loss division and reporting higher social influence for weight loss were associated with greater percent weight loss (p’s≤.002). Similarly, achieving a clinically significant (5%) weight loss tended to cluster within teams (ICC=0.09;p<.001) and having more teammates in the weight loss division and higher social influence for weight loss were associated with increased likelihood of achieving a 5% weight loss (OR=1.06; OR=1.20, respectively). These results suggest that teammates affect weight loss outcomes during a team-based intervention. Harnessing and maximizing teammate influence for weight loss may enhance weight losses in large-scale team-based weight loss programs. PMID:22310234

High Temperature Thermosetting Polyimide Nanocomposites Prepared with Reduced Charge Organoclay

NASA Technical Reports Server (NTRS)

Campbell, Sandi; Liang, Margaret I.

2005-01-01

The naturally occurring sodium and calcium cations found in bentonite clay galleries were exchanged with lithium cations. Following the cation exchange, a series of reduced charge clays were prepared by heat treatment of the lithium bentonite at 130 C, 150 C, or 170 C. Inductively coupled plasma (ICP) analysis showed that heating the lithium clay at elevated temperatures reduced its cation exchange capacity. Ion exchange of heat-treated clays with either a protonated alkyl amine or a protonated aromatic diamine resulted in decreasing amounts of the organic modifier incorporated into the lithium clay. The level of silicate dispersion in a thermosetting polyimide matrix was dependent upon the temperature of Li-clay heat treatment as well as the organic modification. In general, clays treated at 150 C or 170 C, and exchanged with protonated octadcylamine or protonated 2,2'-dimethlybenzidine (DMBZ) showed a higher degree of dispersion than clays treated at 130 C, or exchanged with protonated dodecylamine. Dynamic mechanical analysis showed little change in the storage modulus or T(sub g) of the nanocomposites compared to the base resin. However, long term isothermal aging of the samples showed a significant decrease in the resin oxidative weight loss. Nanocomposite samples aged in air for 1000 hours at 288 C showed of to a decrease in weight loss compared to that of the base resin. This again was dependent on the temperature at which the Li-clay was heated and the choice of organic modification.

Corrosion of Nickel-Based Alloys in Ultra-High Temperature Heat Transfer Fluid

NASA Astrophysics Data System (ADS)

Wang, Tao; Reddy, Ramana G.

2017-03-01

MgCl2-KCl binary system has been proposed to be used as high temperature reactor coolant. Due to its relatively low melting point, good heat capacity and excellent thermal stability, this system can also be used in high operation temperature concentrating solar power generation system as heat transfer fluid (HTF). The corrosion behaviors of nickel based alloys in MgCl2-KCl molten salt system at 1,000 °C were determined based on long-term isothermal dipping test. After 500 h exposure tests under strictly maintained high purity argon gas atmosphere, the weight loss and corrosion rate analysis were conducted. Among all the tested samples, Ni-201 demonstrated the lowest corrosion rate due to the excellent resistance of Ni to high temperature element dissolution. Detailed surface topography and corrosion mechanisms were also determined by using scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS).

Synthesis, spectroscopic characterization and a comparative study of the corrosion inhibitive efficiency of an α-aminophosphonate and Schiff base derivatives: Experimental and theoretical investigations

NASA Astrophysics Data System (ADS)

Benbouguerra, Khalissa; Chafaa, Salah; Chafai, Nadjib; Mehri, Mouna; Moumeni, Ouahiba; Hellal, Abdelkader

2018-04-01

New α-aminophosphonate (α-APD) and Schiff base (E-NDPIMA) derivatives have been prepared and their structures ware proved by IR, UV-Vis, 1H, 13C and 31P NMR spectroscopy. Their inhibitive capacities on the XC48 carbon steel corrosion in 0.5 mol L-1 H2SO4 solution were explored by weight loss, Tafel polarization, electrochemical impedance spectroscopy (EIS) and atomic force microscope (AFM). Experimental results illustrate that the synthesized compounds are an effectives inhibitors and the adsorption of inhibitors molecules on the carbon steel surface obeys Langmuir adsorption isotherm. In addition, quantum chemical calculations performed with density function theory (DFT) method have been used to correlate the inhibition efficiency established experimentally. Also, the molecular dynamics simulations have been utilized to simulate the interactions between the inhibitors molecules and Fe (100) surface in aqueous solution.

Silicone modified resins for graphite fiber laminates

NASA Technical Reports Server (NTRS)

Frost, L. W.; Bower, G. M.

1979-01-01

The development of silicon modified resins for graphite fiber laminates which will prevent the dispersal of graphite fibers when the composites are burned is discussed. Eighty-five silicone modified resins were synthesized and evaluated including unsaturated polyesters, thermosetting methacrylates, epoxies, polyimides, and phenolics. Neat resins were judged in terms of Si content, homogeneity, hardness, Char formation, and thermal stability. Char formation was estimated by thermogravimetry to 1,000 C in air and in N2. Thermal stability was evaluated by isothermal weight loss measurements for 200 hrs in air at three temperatures. Four silicone modified epoxies were selected for evaluation in unidirectional filament wound graphite laminates. Neat samples of these resins had 1,000 C char residues of 25 to 50%. The highest flexural values measured for the laminates were a strength of 140 kpsi and a modulus of 10 Mpsi. The highest interlaminar shear strength was 5.3 kpsi.

Theoretical, thermodynamic and electrochemical analysis of biotin drug as an impending corrosion inhibitor for mild steel in 15% hydrochloric acid

PubMed Central

Xu, Xihua; Sun, Zhipeng; Ansari, K. R.; Lin, Yuanhua

2017-01-01

The corrosion mitigation efficiency of biotin drug for mild steel in 15% hydrochloric acid was thoroughly investigated by weight loss and electrochemical methods. The surface morphology was studied by the contact angle, scanning electrochemical microscopy, atomic force microscopy and scanning electron microscopy methods. Quantum chemical calculation and Fukui analysis were done to correlate the experimental and theoretical data. The influence of the concentration of inhibitor, immersion time, temperature, activation energy, enthalpy and entropy has been reported. The mitigation efficiency of biotin obtained by all methods was in good correlation with each other. Polarization studies revealed that biotin acted as a mixed inhibitor. The adsorption of biotin was found to obey the Langmuir adsorption isotherm. Surface studies showed the hydrophobic nature of the steel with inhibitor and vindicated the formation of a film on the metal surface that reduced the corrosion rate. PMID:29308235

Alginate biopolymer as green corrosion inhibitor for copper in 1 M hydrochloric acid: Experimental and theoretical approaches

NASA Astrophysics Data System (ADS)

Jmiai, A.; El Ibrahimi, B.; Tara, A.; El Issami, S.; Jbara, O.; Bazzi, L.

2018-04-01

The anti-corrosion behavior of sodium alginate (SA) on copper in the 1 M hydrochloric medium was carried out using weight loss and electrochemical measurements. The obtained results show that the inhibition increases with SA concentration and then reaches a maximum of 83% at a concentration of 0.1 mg L-1. The effect of temperature on the reactions of copper corrosion inhibition and analyzing the thermodynamic parameters revealed that the mode of adsorption has a physical nature and obeys the Langmuir isotherm. The surface morphology was performed by scanning electron microscopy coupled with energy dispersive X-ray spectrometry and atomic force microscopy. To better understand the adsorption mechanism, describing the relationship between inhibitory ability and the molecular structure of SA, quantum calculations using density functional theory were performed. Monte Carlo simulation approache was performed to know well of the relationship between the inhibition ability and molecular structure of alginate.

Interactions at the mild steel acid solution interface in the presence of O-fumaryl-chitosan: Electrochemical and surface studies.

PubMed

Sangeetha, Y; Meenakshi, S; Sundaram, C Sairam

2016-01-20

The performance of synthesised O-fumaryl-chitosan (OFC) as corrosion inhibitor for mild steel in 1M HCl has been evaluated through various studies. The initial screening by weight loss method revealed the good inhibition efficiency by the inhibitor. Thermodynamic and kinetic parameters have been calculated and discussed. The mode of adsorption is physical in nature and it follows Langmuir adsorption isotherm. Electrochemical measurements supported the inhibition of mild steel by the fumaryl derivative of chitosan. Polarisation studies provided the information that the inhibition is of mixed type. The formation of inhibitor film is assured by surface morphological studies with Scanning electron microscopy (SEM) and Atomic force microscopy (AFM). The mechanism of inhibition is derived from the Fourier-transform infrared (FTIR) spectroscopy and zero charge potential measurement. The adsorbed film is characterised using FTIR and X-ray diffraction studies (XRD). Copyright © 2015 Elsevier Ltd. All rights reserved.

Anti-Corrosion Performance of 1,3-BENZOTHIAZOLE on 410 Martensitic Stainless Steel in H2SO4

NASA Astrophysics Data System (ADS)

Loto, Roland Tolulope

The corrosion inhibition effect of synthesized 1,3-benzothiazole at very low concentrations on 410 martensitic stainless steel in 3MH2SO4 solution was studied through potentiodynamic polarization and weight loss measurements. The observation showed that the organic compound performed effectively with average inhibition efficiencies of 94% and 98% at the concentrations studied from both electrochemical methods due to the inhibition action of protonated inhibitor molecules in the acid solution. The amine and aromatics functional groups of the molecules active in the corrosion inhibition reaction were exposed from Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) spectroscopic analysis. Thermodynamic calculations showed cationic adsorption to be chemisorption adsorption, obeying the Langmuir adsorption isotherm. Images from optical microscopy showed an improved morphology in comparison to images from corroded stainless steel. Severe surface deterioration and macro-pits were observed in the uninhibited samples.

Modeling of adsorption isotherms of phenol and chlorophenols onto granular activated carbon. Part I. Two-parameter models and equations allowing determination of thermodynamic parameters.

PubMed

Hamdaoui, Oualid; Naffrechoux, Emmanuel

2007-08-17

The adsorption equilibrium isotherms of five phenolic compounds from aqueous solutions onto granular activated carbon (GAC) were studied and modeled. Phenol (Ph), 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (DCP), and 2,4,6-trichlorophenol (TCP) were chosen for the adsorption tests. To predict the adsorption isotherms and to determine the characteristic parameters for process design, seven isotherm models: Langmuir (five linear forms), Freundlich, Elovich, Temkin, Fowler-Guggenheim, Kiselev, and Hill-de Boer models were applied to experimental data. The results reveal that the adsorption isotherm models fitted the data in the order: Fowler-Guggenheim>Hill-de Boer>Temkin>Freundlich>Kiselev>Langmuir isotherms. Adsorption isotherms modeling shows that the interaction of phenolic compounds with activated carbon surface is localized monolayer adsorption, that is adsorbed molecules are adsorbed at definite, localized sites. Each site can accommodate only one molecule. The interaction among adsorbed molecules is repulsive and there is no association between them, adsorption is carried out on energetically different sites and is an exothermic process. Uptake of phenols increases in the order Ph<2-CP<4-CP

High-frequency intrinsic dynamics of the electrocaloric effect from direct atomistic simulations

NASA Astrophysics Data System (ADS)

Lisenkov, S.; Ponomareva, I.

2018-05-01

We propose a computational methodology capable of harvesting isothermal heat and entropy change in molecular dynamics simulations. The methodology is applied to study high-frequency dynamics of the electrocaloric effect (ECE) in ferroelectric PbTiO3. ECE is associated with a reversible change in temperature under adiabatic application of electric field or with a reversible change in entropy under isothermal application of the electric field. Accurate assessment of electrocaloric performance requires the knowledge of three quantities: isothermal heat, isothermal entropy change, and adiabatic temperature change. Our methodology allows computations of all these quantities directly, that is, without restoring to the reversible thermodynamical models. Consequently, it captures both reversible and irreversible effects, which is critical for ECE simulations. The approach is well suited to address the dynamics of the ECE, which so far remains underexplored. We report the following basic features of the intrinsic dynamics of ECE: (i) the ECE is independent of the electric field frequency, rate of application, or field profile; (ii) the effect persists up to the frequencies associated with the onset of dielectric losses and deteriorates from there due to the creation of irreversible entropy; and (iii) in the vicinity of the phase transition and in the paraelectric phase the onset of irreversible dynamics occurs at lower frequency as compared to the ferroelectric phase. The latter is attributed to lower intrinsic soft-mode frequencies and and larger losses in the paraelectric phase.

An assessment of some non-gray global radiation models in enclosures

NASA Astrophysics Data System (ADS)

Meulemans, J.

2016-01-01

The accuracy of several non-gray global gas/soot radiation models, namely the Wide-Band Correlated-K (WBCK) model, the Spectral Line Weighted-sum-of-gray-gases model with one optimized gray gas (SLW-1), the (non-gray) Weighted-Sum-of-Gray-Gases (WSGG) model with different sets of coefficients (Smith et al., Soufiani and Djavdan, Taylor and Foster) was assessed on several test cases from the literature. Non-isothermal (or isothermal) participating media containing non-homogeneous (or homogeneous) mixtures of water vapor, carbon dioxide and soot in one-dimensional planar enclosures and multi-dimensional rectangular enclosures were investigated. For all the considered test cases, a benchmark solution (LBL or SNB) was used in order to compute the relative error of each model on the predicted radiative source term and the wall net radiative heat flux.

Diet for rapid weight loss

MedlinePlus

... loss - rapid weight loss; Overweight - rapid weight loss; Obesity - rapid weight loss; Diet - rapid weight loss ... for people who have health problems because of obesity. For these people, losing a lot of weight ...

Investigation of the Hydraulic Characteristics of Capillary Elements of the Injector Head of Jet Engines under Conditions of Isothermal Flow of A Liquid

NASA Astrophysics Data System (ADS)

Nigodjuk, V. E.; Sulinov, A. V.

2018-01-01

The article presents the results of an experimental study of the hydraulic characteristics of capillary elements of the injector head of jet engines in isothermal fluid flow and the proposed method of their calculation. The main geometric dimensions of the capillaries in the experiment were changed in the following range: Inner diameter from 0.16 to 0.36 mm, length from 4.3 to 158 mm and relative length from 25 to 614 and the inlet edge of the capillaries: sharp or smooth the leading edge. As the working fluid during the tests were distilled water, acetone and ethyl alcohol. Based on the results of a study of the dependences for calculation of ultimate losses in laminar and turbulent flow regimes in capillary tubes with smooth and sharp edges input. The influence of surface tension forces on loss of input on a sharp cutting edge. Experimentally confirmed the possibility of calculating the linear coefficient of hydraulic resistance of capillary tubes with a diameter of 0.16-0.36 mm in isothermal stable during the known dependencies that are valid for hydrodynamically smooth round tube.

Gas adsorption on commercial magnesium stearate: Effects of degassing conditions on nitrogen BET surface area and isotherm characteristics.

PubMed

Lapham, Darren P; Lapham, Julie L

2017-09-15

Commercial grades of magnesium stearate have been analysed by nitrogen adsorption having been pre-treated at temperatures between 30°C and 110°C and in the as-received state. Characteristics of nitrogen adsorption/desorption isotherms are assessed through the linearity of low relative pressure isotherm data and the BET transform plot together with the extent of isotherm hysteresis. Comparison is made between thermal gravimetric analysis and mass loss on drying. Features of gas adsorption isotherms considered atypical are identified and possible causes presented. It is shown that atypical isotherm features and issues of applying BET theory to the calculation of S BET are linked to the presence of hydrated water and that these depend on the hydration state: being more pronounced for the di-hydrate than the mono-hydrate. Dehydration reduces the extent of atypical features. S BET of a mono-hydrate sample is 5.6m 2 g -1 and 3.2m 2 g -1 at 40°C and 100°C degassing respectively but 23.9m 2 g 1 and 5.9m 2 g -1 for di-hydrate containing samples under comparable degassing. Di-hydrated samples also show S BET >15m 2 g 1 , BET C-values <7 and BET correlation coefficients <0.98 before dehydration. Possible mechanisms for atypical isotherms are critically discussed together with the suitability of applying BET theory to nitrogen adsorption data. Copyright © 2017 Elsevier B.V. All rights reserved.

Teammates and social influence affect weight loss outcomes in a team-based weight loss competition.

PubMed

Leahey, Tricia M; Kumar, Rajiv; Weinberg, Brad M; Wing, Rena R

2012-07-01

Team-based internet interventions are increasing in popularity as a way of promoting weight loss in large numbers of individuals. Given that social networks influence health behavior change, this study investigated the effects of teammates and social influence on individual weight loss during a team-based weight loss competition. Shape Up Rhode Island (SURI) 2009 was a 12-week online program open to adult residents of Rhode Island. Participants joined with a team and competed with other teams on weight loss and/or physical activity. Overweight/obese (OW/OB) individuals (N = 3,330; 76% female; age = 46.1 ± 10.8; BMI = 31.2 ± 5.3 kg/m(2)), representing 987 teams, completed the weight loss program. Multilevel modeling was used to examine whether weight loss clustered among teammates and whether percentage of teammates in the weight loss division and reported teammate influence on weight loss were associated with individual weight outcomes. OW/OB completers reported losing 4.2 ± 3.4% of initial body weight. Weight loss was similar among teammates (intraclass correlation coefficient (ICC) = 0.10, P < 0.001). Moreover, having a greater percentage of teammates in the weight loss division and reporting higher social influence for weight loss were associated with greater percent weight loss (P's ≤ 0.002). Similarly, achieving a clinically significant (5%) weight loss tended to cluster within teams (ICC = 0.09; P < 0.001) and having more teammates in the weight loss division and higher social influence for weight loss were associated with increased likelihood of achieving a 5% weight loss (odds ratio (OR) = 1.06; OR = 1.20, respectively). These results suggest that teammates affect weight loss outcomes during a team-based intervention. Harnessing and maximizing teammate influence for weight loss may enhance weight outcomes in large-scale team-based programs.

Isothermal and cyclic oxidation at 1000 and 1100 deg C of four nickel-base alloys: NASA-TRW VIA, B-1900, 713C, and 738X

NASA Technical Reports Server (NTRS)

Barrett, C. A.; Santoro, G. J.; Lowell, C. E.

1973-01-01

The isothermal and cyclic oxidation resistance of four cast Ni-base gamma + gamma prime alloys, NASA-TRW Via, B-1900, 713C, and 738X, was determined in still air at 1000 and 1100 C. The oxidation process was evaluated by specific sample weight change with time, sample thickness change, X-ray diffraction of the scales, and sample metallography. The behavior is discussed in terms of the Cr, Al, and refractory metal contents of the alloys.

The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate).

PubMed

Arellanes-Lozada, Paulina; Olivares-Xometl, Octavio; Guzmán-Lucero, Diego; Likhanova, Natalya V; Domínguez-Aguilar, Marco A; Lijanova, Irina V; Arce-Estrada, Elsa

2014-08-07

Compounds of poly(ionic liquid)s (PILs), derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium) (PImC 12 ), poly(1-vinyl-3-octylimidazolium) (PImC₈) and poly(1-vinyl-3-butylimidazolium) (PImC₄) hexafluorophosphate) were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1-1 M H₂SO₄) by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir's isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC 12 > PImC₈ > PImC₄) to reach 61% for PImC 12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs' partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions.

Loop mediated isothermal amplification: An innovative gene amplification technique for animal diseases.

PubMed

Sahoo, Pravas Ranjan; Sethy, Kamadev; Mohapatra, Swagat; Panda, Debasis

2016-05-01

India being a developing country mainly depends on livestock sector for its economy. However, nowadays, there is emergence and reemergence of more transboundary animal diseases. The existing diagnostic techniques are not so quick and with less specificity. To reduce the economy loss, there should be a development of rapid, reliable, robust diagnostic technique, which can work with high degree of sensitivity and specificity. Loop mediated isothermal amplification assay is a rapid gene amplification technique that amplifies nucleic acid under an isothermal condition with a set of designed primers spanning eight distinct sequences of the target. This assay can be used as an emerging powerful, innovative gene amplification diagnostic tool against various pathogens of livestock diseases. This review is to highlight the basic concept and methodology of this assay in livestock disease.

Low-maintenance energy requirements of obese dogs after weight loss.

PubMed

German, Alexander J; Holden, Shelley L; Mather, Nicola J; Morris, Penelope J; Biourge, Vincent

2011-10-01

Weight rebound after successful weight loss is a well-known phenomenon in humans and dogs, possibly due to the fact that energy restriction improves metabolic efficiency, reducing post-weight-loss maintenance energy requirements (MER). The aim of the present study was to estimate post-weight-loss MER in obese pet dogs that had successfully lost weight and did not subsequently rebound. A total of twenty-four obese dogs, successfully completing a weight management programme at the Royal Canin Weight Management Clinic, University of Liverpool (Wirral, UK), were included. In all dogs, a period of >14 d of stable weight ( < 1 % change) was identified post-weight loss, when food intake was constant and activity levels were stable (assessed via owners' diary records). Post-weight-loss MER was indirectly estimated by determining dietary energy consumption during this stable weight period. Multivariable linear regression was used to identify factors that were associated with post-weight-loss MER. The mean length of stable weight after weight loss was 54 (SD 34.1) d. During this time, MER was 285 (SD 54.8) kJ/kg(0.75) per d. The rate of prior weight loss and food intake during the weight-loss phase was positively associated with post-weight-loss MER, while the amount of lean tissue lost was negatively associated with post-weight-loss MER. MER are low after weight loss in obese pet dogs (typically only 10 % more than required during weight-loss MER), which has implications for what should constitute the optimal diet during this period. Preserving lean tissue during weight loss may maximise post-weight-loss MER and help prevent rebound.

Delay discounting and utility for money or weight loss.

PubMed

Sze, Y Y; Slaven, E M; Bickel, W K; Epstein, L H

2017-03-01

Obesity is related to a bias towards smaller immediate over larger delayed rewards. This bias is typically examined by studying single commodity discounting. However, weight loss often involves choices among multiple commodities. To our knowledge, no research has examined delay discounting of delayed weight loss compared with other commodities. We examined single commodity discounting of money and cross commodity discounting of money and weight loss in a sample of 84 adults with obesity or overweight statuses interested in weight loss. The exchange rate between money and weight loss was calculated, and participants completed two delay discounting tasks: money now versus money later and money now versus weight loss later. Participants discounted weight loss more than money ( p  < 0.001). When participants were divided into those who preferred weight loss ( n  = 61) versus money ( n  = 23), those who preferred money over weight loss discounted weight loss even more than individuals that preferred weight loss ( p  = 0.003). Greater discounting of weight loss for those who preferred money suggest that idiosyncratic preferences are related to multiple commodity discounting, and greater discounting of weight loss across all participants provide insight on important challenges for weight control.

Weight Loss Strategies Utilized in a Men's Weight Loss Intervention

ERIC Educational Resources Information Center

Crane, Melissa M.; Lutes, Lesley D.; Sherwood, Nancy E.; Ward, Dianne S.; Tate, Deborah F.

2018-01-01

Men are underrepresented in weight loss programs and little is currently known about the weight loss strategies men prefer. This study describes the weight loss strategies used by men during a men-only weight loss program. At baseline, 3 months, and 6 months, participants reported how frequently they used 45 weight loss strategies including…

Comparing Weight Loss-Maintenance Outcomes of a Worksite-Based Lifestyle Program Delivered via DVD and Face-to-Face: A Randomized Trial.

PubMed

Ing, Claire Townsend; Miyamoto, Robin E S; Fang, Rui; Antonio, Mapuana; Paloma, Diane; Braun, Kathryn L; Kaholokula, Joseph Keawe'aimoku

2018-03-01

Native Hawaiians and other Pacific Islanders have high rates of overweight and obesity compared with other ethnic groups in Hawai'i. Effective weight loss and weight loss-maintenance programs are needed to address obesity and obesity-related health inequities for this group. Compare the effectiveness of a 9-month, worksite-based, weight loss-maintenance intervention delivered via DVD versus face-to-face in continued weight reduction and weight loss maintenance beyond the initial weight loss phase. We tested DVD versus face-to-face delivery of the PILI@Work Program's 9-month, weight loss-maintenance phase in Native Hawaiian-serving organizations. After completing the 3-month weight loss phase, participants ( n = 217) were randomized to receive the weight loss-maintenance phase delivered via trained peer facilitators or DVDs. Participant assessments at randomization and postintervention included weight, height, blood pressure, physical functioning, exercise frequency, and fat intake. Eighty-three face-to-face participants were retained at 12 months (74.1%) compared with 73 DVD participants (69.5%). There was no significant difference between groups in weight loss or weight loss maintenance. The number of lessons attended in Phase 1 of the intervention (β = 0.358, p = .022) and baseline systolic blood pressure (β = -0.038, p = .048) predicted percent weight loss at 12 months. Weight loss maintenance was similar across groups. This suggests that low-cost delivery methods for worksite-based interventions targeting at-risk populations can help address obesity and obesity-related disparities. Additionally, attendance during the weight loss phase and lower baseline systolic blood pressure predicted greater percent weight loss during the weight loss-maintenance phase, suggesting that early engagement and initial physical functioning improve long-term weight loss outcomes.

The Role of Stigma in Weight Loss Maintenance Among U.S. Adults.

PubMed

Puhl, Rebecca M; Quinn, Diane M; Weisz, Bradley M; Suh, Young J

2017-10-01

Challenges of maintaining long-term weight loss are well-established and present significant obstacles in obesity prevention and treatment. A neglected but potentially important barrier to weight-loss maintenance is weight stigmatization. We examined the role of weight stigma-experienced and internalized-as a contributor to weight-loss maintenance and weight regain in adults. A diverse, national sample of 2702 American adults completed an online battery of questionnaires assessing demographics, weight-loss history, subjective weight category, experienced and internalized weight stigma, weight-monitoring behaviors, physical activity, perceived stress, and physical health. Analyses focused exclusively on participants who indicated that their body weight a year ago was at least 10% less than their highest weight ever (excluding pregnancy), the weight loss was intentional, and that attempts to lose or maintain weight occurred during the past year (n = 549). Participants were further classified as weight regainers (n = 235) or weight-loss maintainers (n = 314) based on subsequent weight loss/gain. Data were collected in 2015 and analyzed in 2016. Hierarchical logistic regression models showed that internalized weight stigma and subjective weight category made significant individual contributions to prediction of weight-loss maintenance, even after accounting for demographics, perceived stress, experienced stigma, physical health, and weight-loss behaviors. For every one-unit increase in internalized weight stigma, the odds of maintaining weight loss decreased by 28% (95% CI: 14-40%, p < .001). Findings provide initial evidence that overlooked psychosocial factors, like weight stigma, may hinder weight-loss maintenance. Implications for addressing stigma in obesity-focused clinical interventions are highlighted.

Exploring the problem of mold growth and the efficacy of various mold inhibitor methods during moisture sorption isotherm measurements.

PubMed

Yu, X; Martin, S E; Schmidt, S J

2008-03-01

Mold growth is a common problem during the equilibration of food materials at high relative humidity values using the standard saturated salt slurry method. Exposing samples to toluene vapor and mixing samples with mold inhibitor chemicals are suggested methods for preventing mold growth while obtaining isotherms. However, no published research was found that examined the effect of mold growth on isotherm performance or the efficacy of various mold inhibitor methods, including their possible effect on the physicochemical properties of food materials. Therefore, the objectives of this study were to (1) explore the effect of mold growth on isotherm performance in a range of food materials, (2) investigate the effectiveness of 4 mold inhibitor methods, irradiation, 2 chemical inhibitors (potassium sorbate and sodium acetate), and toluene vapor, on mold growth on dent corn starch inoculated with A. niger, and (3) examine the effect of mold inhibitor methods on the physicochemical properties of dent corn starch, including isotherm performance, pasting properties, gelatinization temperature, and enthalpy. Mold growth was found to affect starch isotherm performance by contributing to weight changes during sample equilibration. Among the 4 mold inhibitor methods tested, irradiation and toluene vapor were found to be the most effective for inhibiting growth of A. niger on dent cornstarch. However, both methods exhibited a significant impact on the starches' physiochemical properties, suggesting the need to probe the efficacy of other mold inhibitor methods and explore the use of new rapid isotherm instruments, which hamper mold growth by significantly decreasing measurement time.

Weight-loss medicines

MedlinePlus

Prescription weight loss drugs; Diabetes - weight loss drugs; Obesity - weight loss drugs; Overweight - weight loss drugs ... DH, et al.; Endocrine Society. Pharmacological management of obesity: an endocrine Society clinical practice guideline. J Clin ...

Parameterizing sorption isotherms using a hybrid global-local fitting procedure.

PubMed

Matott, L Shawn; Singh, Anshuman; Rabideau, Alan J

2017-05-01

Predictive modeling of the transport and remediation of groundwater contaminants requires an accurate description of the sorption process, which is usually provided by fitting an isotherm model to site-specific laboratory data. Commonly used calibration procedures, listed in order of increasing sophistication, include: trial-and-error, linearization, non-linear regression, global search, and hybrid global-local search. Given the considerable variability in fitting procedures applied in published isotherm studies, we investigated the importance of algorithm selection through a series of numerical experiments involving 13 previously published sorption datasets. These datasets, considered representative of state-of-the-art for isotherm experiments, had been previously analyzed using trial-and-error, linearization, or non-linear regression methods. The isotherm expressions were re-fit using a 3-stage hybrid global-local search procedure (i.e. global search using particle swarm optimization followed by Powell's derivative free local search method and Gauss-Marquardt-Levenberg non-linear regression). The re-fitted expressions were then compared to previously published fits in terms of the optimized weighted sum of squared residuals (WSSR) fitness function, the final estimated parameters, and the influence on contaminant transport predictions - where easily computed concentration-dependent contaminant retardation factors served as a surrogate measure of likely transport behavior. Results suggest that many of the previously published calibrated isotherm parameter sets were local minima. In some cases, the updated hybrid global-local search yielded order-of-magnitude reductions in the fitness function. In particular, of the candidate isotherms, the Polanyi-type models were most likely to benefit from the use of the hybrid fitting procedure. In some cases, improvements in fitness function were associated with slight (<10%) changes in parameter values, but in other cases significant (>50%) changes in parameter values were noted. Despite these differences, the influence of isotherm misspecification on contaminant transport predictions was quite variable and difficult to predict from inspection of the isotherms. Copyright © 2017 Elsevier B.V. All rights reserved.

First-day newborn weight loss predicts in-hospital weight nadir for breastfeeding infants.

PubMed

Flaherman, Valerie J; Bokser, Seth; Newman, Thomas B

2010-08-01

Exclusive breastfeeding reduces infant infectious disease. Losing > or =10% birth weight may lead to formula use. The predictive value of first-day weight loss for subsequent weight loss has not been studied. The objective of the present study was to evaluate the relationship between weight loss at <24 hours and subsequent in-hospital weight loss > or =10%. For 1,049 infants, we extracted gestational age, gender, delivery method, feeding type, and weights from medical records. Weight nadir was defined as the lowest weight recorded during birth hospitalization. We used multivariate logistic regression to assess the effect of first-day weight loss on subsequent in-hospital weight loss. Mean in-hospital weight nadir was 6.0 +/- 2.6%, and mean age at in-hospital weight nadir was 38.7 +/- 18.5 hours. While in the hospital 6.4% of infants lost > or =10% of birth weight. Infants losing > or =4.5% birth weight at <24 hours had greater risk of eventual in-hospital weight loss > or =10% (adjusted odds ratio 3.57 [1.75, 7.28]). In this cohort, 798 (76.1%) infants did not have documented weight gain while in the hospital. Early weight loss predicts higher risk of > or =10% in-hospital weight loss. Infants with high first-day weight loss could be targeted for further research into improved interventions to promote breastfeeding.

Greater weight loss among men participating in a commercial weight loss program: a pooled analysis of 2 randomized controlled trials.

PubMed

Barraj, Leila M; Murphy, Mary M; Heshka, Stanley; Katz, David L

2014-02-01

Being overweight and obese are significant health concerns for men and women, yet despite comparable needs for effective weight loss and maintenance strategies, little is known about the success of commercial weight loss programs in men. This study tests the hypothesis that men participating in a commercial weight loss program (Weight Watchers) had significantly greater weight loss than men receiving limited support from health professionals for weight loss (controls). A pooled analysis of weight loss and related physiologic parameter data from 2 randomized clinical trials was conducted. After 12 months, analysis of covariance tests showed that men in the commercial program group (n = 85) lost significantly more weight (P < .01) than men in the control group (n = 84); similar significant differences were observed for body mass index and waist circumference. These results suggest that participation in a commercial weight loss program may be a more effective means to lose weight and maintain weight loss. Published by Elsevier Inc.

Effect of sodium carbonate catalyst weight on production of bio-oil via thermochemical liquefaction of corncobs in ethanol-water solution

NASA Astrophysics Data System (ADS)

Sembodo, Bregas Siswahjono Tatag; Sulistyo, Hary; Sediawan, Wahyudi Budi; Fahrurrozi, Mohammad

2018-02-01

Lignocellulosic biomass has recently received serious attention as an energy source that can replace fossil fuels. Corncob is one of lignocellulosic biomass wastes, which can be further processed into bio-oil through thermochemical liquefaction process. Bio-oil is expected to be further processed into fuel oil. In this research the effect of Na2CO3 catalyst weight on the yield of bio-oil was investigated. The composition of bio-oil produced in this process was analyzed by GC-MS. Bio-oil formation rate were analyzed through mathematical model development. First model aasumed as an isothermal process, while second model was not. It is found that both models were able to provide a good approach to experimental data. The average reaction rate constants was obtained from isothermal model, while the activation energy level and collision factors were obtained from non-isothermal model. The reaction rate will increase by addition of Na2CO3 (0 - 0.5 g) as catalyst to 250 mL system solution, then the activation energy will decrease from 1964.265 joules/mole to 1029.994 joules/mole. The GC-MS analysis results showed that the bio-oil were contained of ester compounds, phenolic compounds, cyclic compunds, heterocyclic compounds, and poly-alcohols compounds.

Competitive adsorption of phenolic compounds from aqueous solution using sludge-based activated carbon.

PubMed

Mohamed, E F; Andriantsiferana, C; Wilhelm, A M; Delmas, H

2011-01-01

Preparation of activated carbon from sewage sludge is a promising approach to produce cheap and efficient adsorbent for pollutants removal as well as to dispose of sewage sludge. The first objective of this study was to investigate the physical and chemical properties (BET surface area, ash and elemental content, surface functional groups by Boehm titration and weight loss by thermogravimetric analysis) of the sludge-based activated carbon (SBAC) so as to give a basic understanding of its structure and to compare to those of two commercial activated carbons, PICA S23 and F22. The second and main objective was to evaluate the performance of SBAC for single and competitive adsorption of four substituted phenols (p-nitrophenol, p-chlorophenol, p-hydroxy benzoic acid and phenol) from their aqueous solutions. The results indicated that, despite moderate micropore and mesopore surface areas, SBAC had remarkable adsorption capacity for phenols, though less than PICA carbons. Uptake of the phenolic compound was found to be dependent on both the porosity and surface chemistry of the carbons. Furthermore, the electronegativity and the hydrophobicity of the adsorbate have significant influence on the adsorption capacity. The Langmuir and Freundlich models were used for the mathematical description of the adsorption equilibrium for single-solute isotherms. Moreover, the Langmuir-Freundlich model gave satisfactory results for describing multicomponent system isotherms. The capacity of the studied activated carbons to adsorb phenols from a multi-solute system was in the following order: p-nitrophenol > p-chlorophenol > PHBA > phenol.

Mercerized mesoporous date pit activated carbon—A novel adsorbent to sequester potentially toxic divalent heavy metals from water

PubMed Central

Aldawsari, Abdullah; Hameed, B. H.; Alqadami, Ayoub Abdullah; Siddiqui, Masoom Raza; Alothman, Zeid Abdullah; Ahmed, A. Yacine Badjah Hadj

2017-01-01

A substantive approach converting waste date pits to mercerized mesoporous date pit activated carbon (DPAC) and utilizing it in the removal of Cd(II), Cu(II), Pb(II), and Zn(II) was reported. In general, rapid heavy metals adsorption kinetics for Co range: 25–100 mg/L was observed, accomplishing 77–97% adsorption within 15 min, finally, attaining equilibrium in 360 min. Linear and non-linear isotherm studies revealed Langmuir model applicability for Cd(II) and Pb(II) adsorption, while Freundlich model was fitted to Zn(II) and Cu(II) adsorption. Maximum monolayer adsorption capacities (qm) for Cd(II), Pb(II), Cu(II), and Zn(II) obtained by non-linear isotherm model at 298 K were 212.1, 133.5, 194.4, and 111 mg/g, respectively. Kinetics modeling parameters showed the applicability of pseudo-second-order model. The activation energy (Ea) magnitude revealed physical nature of adsorption. Maximum elution of Cu(II) (81.6%), Zn(II) (70.1%), Pb(II) (96%), and Cd(II) (78.2%) were observed with 0.1 M HCl. Thermogravimetric analysis of DPAC showed a total weight loss (in two-stages) of 28.3%. Infra-red spectral analysis showed the presence of carboxyl and hydroxyl groups over DPAC surface. The peaks at 820, 825, 845 and 885 cm-1 attributed to Zn–O, Pb–O, Cd–O, and Cu–O appeared on heavy metals saturated DPAC, confirmed their binding on DPAC during the adsorption. PMID:28910368

Mercerized mesoporous date pit activated carbon-A novel adsorbent to sequester potentially toxic divalent heavy metals from water.

PubMed

Aldawsari, Abdullah; Khan, Moonis Ali; Hameed, B H; Alqadami, Ayoub Abdullah; Siddiqui, Masoom Raza; Alothman, Zeid Abdullah; Ahmed, A Yacine Badjah Hadj

2017-01-01

A substantive approach converting waste date pits to mercerized mesoporous date pit activated carbon (DPAC) and utilizing it in the removal of Cd(II), Cu(II), Pb(II), and Zn(II) was reported. In general, rapid heavy metals adsorption kinetics for Co range: 25-100 mg/L was observed, accomplishing 77-97% adsorption within 15 min, finally, attaining equilibrium in 360 min. Linear and non-linear isotherm studies revealed Langmuir model applicability for Cd(II) and Pb(II) adsorption, while Freundlich model was fitted to Zn(II) and Cu(II) adsorption. Maximum monolayer adsorption capacities (qm) for Cd(II), Pb(II), Cu(II), and Zn(II) obtained by non-linear isotherm model at 298 K were 212.1, 133.5, 194.4, and 111 mg/g, respectively. Kinetics modeling parameters showed the applicability of pseudo-second-order model. The activation energy (Ea) magnitude revealed physical nature of adsorption. Maximum elution of Cu(II) (81.6%), Zn(II) (70.1%), Pb(II) (96%), and Cd(II) (78.2%) were observed with 0.1 M HCl. Thermogravimetric analysis of DPAC showed a total weight loss (in two-stages) of 28.3%. Infra-red spectral analysis showed the presence of carboxyl and hydroxyl groups over DPAC surface. The peaks at 820, 825, 845 and 885 cm-1 attributed to Zn-O, Pb-O, Cd-O, and Cu-O appeared on heavy metals saturated DPAC, confirmed their binding on DPAC during the adsorption.

ASTM E 1559 method for measuring material outgassing/deposition kinetics has applications to aerospace, electronics, and semiconductor industries

NASA Technical Reports Server (NTRS)

Garrett, J. W.; Glassford, A. P. M.; Steakley, J. M.

1994-01-01

The American Society for Testing and Materials has published a new standard test method for characterizing time and temperature-dependence of material outgassing kinetics and the deposition kinetics of outgassed species on surfaces at various temperatures. This new ASTM standard, E 1559(1), uses the quartz crystal microbalance (QCM) collection measurement approach. The test method was originally developed under a program sponsored by the United States Air Force Materials Laboratory (AFML) to create a standard test method for obtaining outgassing and deposition kinetics data for spacecraft materials. Standardization by ASTM recognizes that the method has applications beyond aerospace. In particular, the method will provide data of use to the electronics, semiconductor, and high vacuum industries. In ASTM E 1559 the material sample is held in vacuum in a temperature-controlled effusion cell, while its outgassing flux impinges on several QCM's which view the orifice of the effusion cell. Sample isothermal total mass loss (TML) is measured as a function of time from the mass collected on one of the QCM's which is cooled by liquid nitrogen, and the view factor from this QCM to the cell. The amount of outgassed volatile condensable material (VCM) on surfaces at higher temperatures is measured as a function of time during the isothermal outgassing test by controlling the temperatures of the remaining QCM's to selected values. The VCM on surfaces at temperatures in between those of the collector QCM's is determined at the end of the isothermal test by heating the QCM's at a controlled rate and measuring the mass loss from the end of the QCM's as a function of time and temperature. This reevaporation of the deposit collected on the QCM's is referred to as QCM thermogravimetric analysis. Isothermal outgassing and deposition rates can be determined by differentiating the isothermal TML and VCM data, respectively, while the evaporation rates of the species can be obtained as a function of temperature by differentiating the QCM thermogravimetric analysis data.

Changes in weight control behaviors and hedonic hunger during a 12-week commercial weight loss program.

PubMed

O'Neil, Patrick M; Theim, Kelly R; Boeka, Abbe; Johnson, Gail; Miller-Kovach, Karen

2012-12-01

Greater use of key self-regulatory behaviors (e.g., self-monitoring of food intake and weight) is associated with greater weight loss within behavioral weight loss treatments, although this association is less established within widely-available commercial weight loss programs. Further, high hedonic hunger (i.e., susceptibility to environmental food cues) may present a barrier to successful behavior change and weight loss, although this has not yet been examined. Adult men and women (N=111, body mass index M±SD=31.5±2.7kg/m(2)) were assessed before and after participating in a 12-week commercial weight loss program. From pre- to post-treatment, reported usage of weight control behaviors improved and hedonic hunger decreased, and these changes were inversely associated. A decrease in hedonic hunger was associated with better weight loss. An improvement in reported weight control behaviors (e.g., self-regulatory behaviors) was associated with better weight loss, and this association was even stronger among individuals with high baseline hedonic hunger. Findings highlight the importance of specific self-regulatory behaviors within weight loss treatment, including a commercial weight loss program developed for widespread community implementation. Assessment of weight control behavioral skills usage and hedonic hunger may be useful to further identify mediators of weight loss within commercial weight loss programs. Future interventions might specifically target high hedonic hunger and prospectively examine changes in hedonic hunger during other types of weight loss treatment to inform its potential impact on sustained behavior change and weight control. Copyright © 2012 Elsevier Ltd. All rights reserved.

Enhanced corrosion resistance of stainless steel type 316 in sulphuric acid solution using eco-friendly waste product

NASA Astrophysics Data System (ADS)

Sanni, O.; Popoola, A. P. I.; Fayomi, O. S. I.

2018-06-01

Literature has shown that different organic compounds are effective corrosion inhibitors for metal in acidic environments. Such compounds usually contain oxygen, nitrogen or sulphur and function through adsorption on the metal surface, thereby creating a barrier for corrosion attack. Unfortunately, these organic compounds are toxic, scarce and expensive. Therefore, plants, natural product and natural oils have been posed as cheap, environmentally acceptable, abundant, readily available and effective molecules having low environmental impact. The corrosion resistance of austenitic stainless steel Type 316 in the presence of eco-friendly waste product was studied using weight loss and potentiodynamic polarization techniques in 0.5 M H2SO4. The corrosion rate and corrosion potential of the steel was significantly altered by the studied inhibitor. Results show that increase in concentration of the inhibitor hinders the formation of the passive film. Experimental observation shows that its pitting potential depends on the concentration of the inhibitor in the acid solution due to adsorption of anions at the metal film interface. The presence of egg shell powder had a strong influence on the corrosion resistance of stainless steel Type 316 with highest inhibition efficiency of 94.74% from weight loss analysis, this is as a result of electrochemical action and inhibition of the steel by the ionized molecules of the inhibiting compound which influenced the mechanism of the redox reactions responsible for corrosion and surface deterioration. Inhibitor adsorption fits the Langmuir isotherm model. The two methods employed for the corrosion assessment were in good agreement.

The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pasasa, Norman Vincent A., E-mail: npasasa@gmail.com; Bundjali, Bunbun; Wahyuningrum, Deana

Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,{sup 1}H-NMR andmore » {sup 13}C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir’s adsorption isotherm.« less

First-Day Newborn Weight Loss Predicts In-Hospital Weight Nadir for Breastfeeding Infants

PubMed Central

Bokser, Seth; Newman, Thomas B.

2010-01-01

Abstract Background Exclusive breastfeeding reduces infant infectious disease. Losing ≥10% birth weight may lead to formula use. The predictive value of first-day weight loss for subsequent weight loss has not been studied. The objective of the present study was to evaluate the relationship between weight loss at <24 hours and subsequent in-hospital weight loss ≥10%. Methods For 1,049 infants, we extracted gestational age, gender, delivery method, feeding type, and weights from medical records. Weight nadir was defined as the lowest weight recorded during birth hospitalization. We used multivariate logistic regression to assess the effect of first-day weight loss on subsequent in-hospital weight loss. Results Mean in-hospital weight nadir was 6.0 ± 2.6%, and mean age at in-hospital weight nadir was 38.7 ± 18.5 hours. While in the hospital 6.4% of infants lost ≥10% of birth weight. Infants losing ≥4.5% birth weight at <24 hours had greater risk of eventual in-hospital weight loss ≥10% (adjusted odds ratio 3.57 [1.75, 7.28]). In this cohort, 798 (76.1%) infants did not have documented weight gain while in the hospital. Conclusions Early weight loss predicts higher risk of ≥10% in-hospital weight loss. Infants with high first-day weight loss could be targeted for further research into improved interventions to promote breastfeeding. PMID:20113202

Overweight, Obesity, and Weight Loss

MedlinePlus

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Relations of hedonic hunger and behavioral change to weight loss among adults in a behavioral weight loss program utilizing meal-replacement products.

PubMed

Theim, Kelly R; Brown, Joshua D; Juarascio, Adrienne S; Malcolm, Robert R; O'Neil, Patrick M

2013-11-01

Greater self-regulatory behavior usage is associated with greater weight loss within behavioral weight loss treatments. Hedonic hunger (i.e., susceptibility to environmental food cues) may impede successful behavior change and weight loss. Adult men and women (N = 111, body mass index M ± SD = 35.89 ± 6.97 kg/m(2)) were assessed before and after a 15-week lifestyle change weight loss program with a partial meal-replacement diet. From pre- to post-treatment, reported weight control behavior usage improved and hedonic hunger decreased, and these changes were inversely related. Individuals with higher hedonic hunger scores at baseline showed the greatest weight loss. Similarly, participants with lower baseline use of weight control behaviors lost more weight, and increased weight control behavior usage was associated with greater weight loss-particularly among individuals with low baseline hedonic hunger. Further study is warranted regarding the significance of hedonic hunger in weight loss treatments.

Prevalence and cost of HIV-associated weight loss in a managed care population.

PubMed

Siddiqui, Javeed; Phillips, Amy L; Freedland, Eric S; Sklar, Ami R; Darkow, Theodore; Harley, Carolyn R

2009-05-01

To estimate the prevalence of HIV-associated weight loss among HIV patients in a US managed care population, and compare demographic and clinical characteristics of HIV patients with and without evidence of HIV-associated weight loss. A retrospective observational study was conducted using a large, geographically diverse US managed care population to identify commercial enrollees with HIV/AIDS from 1/1/2005-7/31/2007, based on a combination of HIV/AIDS diagnosis codes or antiretroviral treatment. HIV-associated weight loss status was defined according to an algorithm combining evidence for weight loss-associated conditions, anorexia symptoms, and various treatments for weight loss or wasting. Among HIV patients continuously enrolled in the health plan for one year, patient demographics, treatments, and comorbidities were compared between patients with and without evidence for weight loss. A total of 22,535 patients with HIV/AIDS were identified, including 2098 who met the criteria for weight loss (estimated prevalence 9.3%; 95% CI: 8.9% - 9.7%). Among 12,187 continuously enrolled patients with HIV, 1006 (8.3%) had evidence of HIV-associated weight loss. Patients with HIV-associated weight loss were older (44.1 vs. 42.6 years), and more men had HIV-associated weight loss than women (8.8% vs. 5.3%). A number of comorbidities were more common among patients with HIV-associated weight loss. On average, these patients also had more ambulatory (24.0 vs. 13.4), ER (1.4 vs. 0.8), and inpatient visits (0.5 vs. 0.1). Total annual health care costs for patients with HIV-associated weight loss were more than double (mean $45,686 vs. $19,960) the costs for HIV patients without weight loss. Despite the availability of effective antiretroviral therapy, weight loss remains a problem among patients with HIV. Based on this analysis, almost 1 in 10 managed care patients with HIV have evidence of HIV-associated weight loss. These patients tend to have more comorbidities, use more health care resources, and incur greater costs compared to patients without HIV-associated weight loss. Patients with HIV-associated weight loss were generally sicker than the non-weight loss cohort; thus, the increased costs observed in this population may not be directly or wholly attributable to HIV-associated weight loss. In addition, limitations common to analyses of administrative claims data should be considered when interpreting these results.

Determinants of Weight Loss prior to Diagnosis in Inflammatory Bowel Disease: A Retrospective Observational Study.

PubMed

Elsherif, Yasser; Alexakis, Christopher; Mendall, Michael

2014-01-01

Aims. To identify prevalence, severity, and environmental determinants of weight loss in inflammatory bowel disease (IBD) patients just prior to time of formal diagnosis. Methodology. IBD patients attending outpatient clinic were questioned about weight loss prior to diagnosis and other environmental and demographic variables. The percentage BMI loss was calculated for each subject and factors associated with weight loss were determined. Results. Four hundred and ninety-four subjects were recruited (237 cases of Crohn's disease (CD) and 257 cases of ulcerative colitis (UC)). Overall, 57% of subjects with CD and 51% of subjects with UC experienced significant weight loss prior to diagnosis (>5% BMI loss). Younger age at diagnosis and history of previous IBD surgery were significantly associated with both lower BMI at diagnosis and increased weight loss prior to diagnosis. In CD patients, increasing age at diagnosis was inversely associated with weight loss prior to diagnosis. Ileal disease was a risk factor of weight loss, whereas prior appendectomy was associated with reduced risk of weight loss. Conclusions. Weight loss is a significant problem for many IBD patients at presentation, especially in younger age and CD with ileal involvement. Appendectomy is associated with diminished weight loss.

Self-Monitoring and Eating-Related Behaviors Associated with 12-Month Weight Loss in Postmenopausal Overweight-to-Obese Women

PubMed Central

Kong, Angela; Beresford, Shirley A.A.; Alfano, Catherine M.; Foster-Schubert, Karen E.; Neuhouser, Marian L.; Johnson, Donna B.; Duggan, Catherine; Wang, Ching-Yun; Xiao, Liren; Jeffery, Robert W.; Bain, Carolyn E.; McTiernan, Anne

2012-01-01

Lifestyle-based interventions, which typically promote various behavioral modification strategies, can serve as a setting for evaluating specific behaviors and strategies thought to promote or hinder weight loss. The aim of this study was to test the associations of self-monitoring (self-weighing, food journal completion) and eating-related (dietary intake, diet-related weight-control strategies, and meal patterns) behaviors with weight loss in a sample of postmenopausal overweight-to-obese women enrolled in a 12-month dietary weight loss intervention. Changes in body weight and adoption of self-monitoring and eating-related behaviors were assessed in 123 participants. Generalized linear models tested associations of these behaviors with 12-month weight change after adjusting for potential confounders. Mean percent weight loss was 10.7%. In the final model, completing more food journals was associated with a greater % weight loss (interquartile range, 3.7% greater weight loss; p<0.0001) while skipping meals (4.3% lower weight loss; p<0.05) and eating out for lunch (at least once a week, 2.5% lower weight loss; p<0.01) were associated with a lower amount of weight loss. These findings suggest that a greater focus on dietary self-monitoring, home-prepared meals, and consuming meals at regular intervals may improve 12-month weight loss among postmenopausal women enrolled in a dietary weight loss intervention. PMID:22795495

A patient-centered electronic tool for weight loss outcomes after Roux-en-Y gastric bypass.

PubMed

Wood, G Craig; Benotti, Peter; Gerhard, Glenn S; Miller, Elaina K; Zhang, Yushan; Zaccone, Richard J; Argyropoulos, George A; Petrick, Anthony T; Still, Christopher D

2014-01-01

BACKGROUND. Current patient education and informed consent regarding weight loss expectations for bariatric surgery candidates are largely based on averages from large patient cohorts. The variation in weight loss outcomes illustrates the need for establishing more realistic weight loss goals for individual patients. This study was designed to develop a simple web-based tool which provides patient-specific weight loss expectations. METHODS. Postoperative weight measurements after Roux-en-Y gastric bypass (RYGB) were collected and analyzed with patient characteristics known to influence weight loss outcomes. Quantile regression was used to create expected weight loss curves (25th, 50th, and 75th %tile) for the 24 months after RYGB. The resulting equations were validated and used to develop web-based tool for predicting weight loss outcomes. RESULTS. Weight loss data from 2986 patients (2608 in the primary cohort and 378 in the validation cohort) were included. Preoperative body mass index (BMI) and age were found to have a high correlation with weight loss accomplishment (P < 0.0001 for each). An electronic tool was created that provides easy access to patient-specific, 24-month weight loss trajectories based on initial BMI and age. CONCLUSIONS. This validated, patient-centered electronic tool will assist patients and providers in patient teaching, informed consent, and postoperative weight loss management.

[Motivation for weight loss among weight loss treatment participants].

PubMed

Czeglédi, Edit

2017-12-01

Unrealistic expectations about weight goal and about weight loss-related benefits can hinder the effort for a successful long-term weight control. To explore weight loss-related goals and their background among overweight/obese patients. Study sample consisted of patients who participated in the inpatient weight loss treatment in the Lipidological Department of Szent Imre Hospital (n = 339, 19% men). Mean age: 50.2 years (SD = 13.47 years), mean BMI: 38.6 (SD = 7.58). self-reported anthropometric data, type and number of treated illnesses, Goals and Relative Weights Questionnaire, Motivations for Weight Loss Scale, Body Shape Questionnaire. Participants would feel disappointed with a possible 10% weight loss in a half-year time span. The acceptable weight loss percentage was higher among women, younger participants and among those who had more excess weight. Motivation regarding the increase in social desirability by weight loss is in association with body dissatisfaction, health related motivation is in association with the number of treated illnesses. Our results are contributing to the understanding of motivational factors behind weight reduction efforts, considering these can improve treatment success rates. Orv Hetil. 2017; 158(49): 1960-1967.

Blogging for weight loss: personal accountability, writing selves, and the weight-loss blogosphere.

PubMed

Leggatt-Cook, Chez; Chamberlain, Kerry

2012-09-01

Body weight is a key concern in contemporary society, with large proportions of the population attempting to control their weight. However, losing weight and maintaining weight loss is notoriously difficult, and new strategies for weight loss attract significant interest. Writing about experiences of weight loss in online journals, or blogging, has recently expanded rapidly. Weight-loss bloggers typically write about daily successes and failures, report calorie consumption and exercise output, and post photographs of their changing bodies. Many bloggers openly court the surveillance of blog readers as a motivation for accountability to their weight-loss goals. Drawing from a sample of weight-loss blogs authored by women, we explore three issues arising from this practice of disclosing a conventionally private activity within an online public domain. First, we examine motivations for blogging, focusing on accountability. Secondly, we consider the online construction of self, exploring how weight-loss bloggers negotiate discourses around fatness, and rework selves as their bodies transform. Finally, we consider the communities of interest that form around weight-loss blogs. This 'blogosphere' provides mutual support for weight loss. However, participating in online social spaces is complicated and bloggers must carefully manage issues of privacy and disclosure. © 2011 The Authors. Sociology of Health & Illness © 2011 Foundation for the Sociology of Health & Illness/Blackwell Publishing Ltd.

The liberating effect of weight loss supplements on dietary control: a field experiment.

PubMed

Chang, Yevvon Y; Chiou, Wen-Bin

2014-09-01

Taking weight-loss supplements may create illusion of protection against weight gain and thereby loosen subsequent dietary self-control. The current study examined whether taking weight-loss supplement would increase food intake and further tested whether positive attitudes toward supplements would increase susceptibility to overeating. Participants were randomly assigned to take either a known placebo or a purported weight loss supplement (actually, the same placebo). After supplement provision, participants' actual food consumption at a reward buffet lunch was recorded. Compared with controls, participants receiving a purported weight loss supplement ate more food at the reward buffet. Perceived progress toward the goal of weight reduction mediated the connection between use of weight loss supplements and subsequent food consumption. Participants with more positive attitudes toward weight loss supplements were more susceptible to the liberating effect of taking weight loss supplements on food intake. Using weight loss supplements may produce unintended consequences on dietary self-regulation. The public should pay more attention to the notion of psychological liberation when using weight loss supplements. Copyright © 2014 Elsevier Inc. All rights reserved.

Recruitment and Retention for a Weight Loss Maintenance Trial Involving Weight Loss Prior to Randomization

PubMed Central

Grubber, J. M.; McVay, M. A.; Olsen, M. K.; Bolton, J.; Gierisch, J. M.; Taylor, S. S.; Maciejewski, M. L.; Yancy, W. S.

2016-01-01

Abstract Objective A weight loss maintenance trial involving weight loss prior to randomization is challenging to implement due to the potential for dropout and insufficient weight loss. We examined rates and correlates of non‐initiation, dropout, and insufficient weight loss during a weight loss maintenance trial. Methods The MAINTAIN trial involved a 16‐week weight loss program followed by randomization among participants losing at least 4 kg. Psychosocial measures were administered during a screening visit. Weight was obtained at the first group session and 16 weeks later to determine eligibility for randomization. Results Of 573 patients who screened as eligible, 69 failed to initiate the weight loss program. In adjusted analyses, failure to initiate was associated with lower age, lack of a support person, and less encouragement for making dietary changes. Among participants who initiated, 200 dropped out, 82 lost insufficient weight, and 222 lost sufficient weight for randomization. Compared to losing sufficient weight, dropping out was associated with younger age and tobacco use, whereas losing insufficient weight was associated with non‐White race and controlled motivation for physical activity. Conclusions Studies should be conducted to evaluate strategies to maximize recruitment and retention of subgroups that are less likely to initiate and be retained in weight loss maintenance trials. PMID:28090340

Self-monitoring and eating-related behaviors are associated with 12-month weight loss in postmenopausal overweight-to-obese women.

PubMed

Kong, Angela; Beresford, Shirley A A; Alfano, Catherine M; Foster-Schubert, Karen E; Neuhouser, Marian L; Johnson, Donna B; Duggan, Catherine; Wang, Ching-Yun; Xiao, Liren; Jeffery, Robert W; Bain, Carolyn E; McTiernan, Anne

2012-09-01

Lifestyle-based interventions, which typically promote various behavior modification strategies, can serve as a setting for evaluating specific behaviors and strategies thought to promote or hinder weight loss. The aim of our study was to test the associations of self-monitoring (ie, self-weighing and food journal completion) and eating-related (ie, dietary intake, diet-related weight-control strategies, and meal patterns) behaviors with weight loss in a sample of postmenopausal overweight-to-obese women enrolled in a 12-month dietary weight loss intervention. Changes in body weight and adoption of self-monitoring and eating-related behaviors were assessed in 123 participants. Generalized linear models tested associations of these behaviors with 12-month weight change after adjusting for potential confounders. Mean percent weight loss was 10.7%. In the final model, completing more food journals was associated with a greater percent weight loss (interquartile range 3.7% greater weight loss; P<0.0001), whereas skipping meals (4.3% lower weight loss; P<0.05) and eating out for lunch (at least once a week, 2.5% lower weight loss; P<0.01) were associated with a lower amount of weight loss. These findings suggest that a greater focus on dietary self-monitoring, home-prepared meals, and consuming meals at regular intervals may improve 12-month weight loss among postmenopausal women enrolled in a dietary weight loss intervention. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Preferences and motivation for weight loss among knee replacement patients: implications for a patient-centered weight loss intervention.

PubMed

Pellegrini, Christine A; Ledford, Gwendolyn; Hoffman, Sara A; Chang, Rowland W; Cameron, Kenzie A

2017-08-01

Most knee replacement patients are overweight/obese, yet are commonly excluded from evidence-based weight loss programs due to mobility limitations and barriers faced around the time of surgery. The purpose of this study was to identify knee replacement patient preferences for weight loss programs and qualitatively understand previous motives for weight loss attempts as well as strategies used to facilitate behavior changes. Patients who were either scheduled to have knee replacement or had one recently completed within the last 3 months were recruited to participate. Patients completed a brief weight loss program preference questionnaire assessing preferred components of a weight loss program (i.e. self-monitoring, educational topics, program duration). Qualitative interviews were completed to identify motives for and strategies used during past weight loss attempts. All interviews were transcribed, de-identified, and analyzed using constant comparative analysis. Twenty patients (11 pre-operative and 9 post-operative) between 47 and 79 years completed the study (55% male, 90% White, and 85% with a BMI ≥25 kg/m 2 ). Patients reported a preference for a weight loss program that starts before surgery, is at least 6 months in duration, and focuses both on diet and exercise. The majority of patients preferred to have a telephone-based program and wanted to track diet and physical activity on a smartphone application. The most common motive for weight loss mentioned by patients related to physical appearance (including how clothing fit), followed by wanting to lose weight to improve knee symptoms or to prevent or delay knee replacement. Strategies that patients identified as helpful during weight loss attempts included joining a formal weight loss program, watching portion sizes, and self-monitoring their dietary intake, physical activity, or weight. This study provides a preliminary examination into the motives for weight loss, strategies utilized during past weight loss attempts, and preferences for future weight loss programs as described by knee replacement patients. These results will help guide the development and adaptation of future patient-centered weight loss programs as well as help clinicians recommend targeted weight programs based on the specific preferences of the knee replacement population.

Does bone loss begin after weight loss ends? Results 2 years after weight loss or regain in postmenopausal women.

PubMed

Von Thun, Nancy L; Sukumar, Deeptha; Heymsfield, Steven B; Shapses, Sue A

2014-05-01

Short-term weight loss is accompanied by bone loss in postmenopausal women. The longer-term impact of weight loss on bone in reduced overweight/obese women compared with women who regained their weight was examined in this study using a case-control design. Postmenopausal women (N = 42; mean [SD] body mass index, 28.3 [2.8] kg/m; mean [SD] age, 60.7 [5.5] y) were recruited 2 years after the start of a 6-month weight loss trial; those who maintained their weight (weight loss maintainer [WL-M] group) were matched to a cohort of women who regained their weight (weight loss regainer [WL-R] group). Serum hormones and bone markers were measured in a subset. Bone mineral density (BMD) at the femoral neck, trochanter, spine, radius, and total body, and soft-tissue composition were taken at baseline, 0.5 years, and 2 years. During weight loss, both groups lost 9.3% (3.4%) of body weight, with no significant difference between the groups. After weight loss, weight change was -0.1% (2.7%) and 6.0% (3.3%) in the WL-M (n = 22) and WL-R (n = 20) groups, respectively. After 2 years, both groups lost BMD at the femoral neck and trochanter (P ≤ 0.01), whereas only the WL-M group reduced BMD at the 1/3 radius (P < 0.001). There was greater BMD loss at the trochanter (-6.8% [5.7%]) and 1/3 radius (-4.5% [3.3%]) in the WL-M group compared with the WL-R group after 2 years. Multiple linear regression showed that change in leg fat mass (but not trunk fat) contributed to trochanter BMD loss (P < 0.05). After 2 years, there is no BMD recovery of weight reduction-induced bone loss, irrespective of weight regain. These data suggest that the period after weight loss may be an important point in time to prevent bone loss for those who maintain weight and those who regain weight.

Serum markers of bone turnover are increased by modest weight loss with or without weight-bearing exercise in overweight premenopausal women.

PubMed

Rector, R Scott; Loethen, Joanne; Ruebel, Meghan; Thomas, Tom R; Hinton, Pamela S

2009-10-01

Weight loss improves metabolic fitness and reduces morbidity and mortality; however, weight reduction also reduces bone mineral density (BMD) and increases bone turnover. Weight-bearing aerobic exercise may preserve bone mass and maintain normal bone turnover during weight reduction. We investigated the impact of weight-bearing and nonweight-bearing exercise on serum markers of bone formation and breakdown during short-term, modest weight loss in overweight premenopausal women. Subjects (n = 36) were assigned to 1 of 3 weight-loss interventions designed to produce a 5% reduction in body weight over 6 weeks: (i) energy restriction only (n = 11; DIET); (ii) energy restriction plus nonweight-bearing exercise (n = 12, CYCLE); or (iii) energy restriction plus weight-bearing exercise (n = 13, RUN). Bone turnover markers were measured in serum collected at baseline and after weight loss. All groups achieved a ~5% reduction in body weight (DIET = 5.2%; CYCLE = 5.0%; RUN = 4.7%). Osteocalcin (OC) and C-terminal telopeptide of type I collagen (CTX) increased with weight loss in all 3 groups (p < 0.05), whereas bone alkaline phosphatase was unaltered by the weight-loss interventions. At baseline, OC and CTX were positively correlated (r = 0.36, p = 0.03), but the strength of this association was diminished (r = 0.30, p = 0.06) after weight loss. Modest weight loss, regardless of method, resulted in a significant increase in both OC and CTX. Low-impact, weight-bearing exercise had no effect on serum markers of bone formation or resorption in premenopausal women during weight loss. Future studies that examine the effects of high-impact, weight-bearing activity on bone turnover and BMD during weight loss are warranted.

Emotional eating is associated with weight loss success among adults enrolled in a weight loss program.

PubMed

Braden, Abby; Flatt, Shirley W; Boutelle, Kerri N; Strong, David; Sherwood, Nancy E; Rock, Cheryl L

2016-08-01

To examine associations between decreased emotional eating and weight loss success; and whether participation in a behavioral weight loss intervention was associated with a greater reduction in emotional eating over time compared to usual care. Secondary data analysis of a randomized controlled trial conducted at two university medical centers with 227 overweight adults with diabetes. Logistic and standard regression analyses examined associations between emotional eating change and weight loss success (i.e., weight loss of ≥7 % of body weight and decrease in BMI). After 6 months of intervention, decreased emotional eating was associated with greater odds of weight loss success (p = .05). The odds of weight loss success for subjects with decreased emotional eating at 12 months were 1.70 times higher than for subjects with increased emotional eating. No differences in change in emotional eating were found between subjects in the behavioral weight loss intervention and usual care. Strategies to reduce emotional eating may be useful to promote greater weight loss among overweight adults with diabetes.

Solution of weakly compressible isothermal flow in landfill gas collection networks

NASA Astrophysics Data System (ADS)

Nec, Y.; Huculak, G.

2017-12-01

Pipe networks collecting gas in sanitary landfills operate under the regime of a weakly compressible isothermal flow of ideal gas. The effect of compressibility has been traditionally neglected in this application in favour of simplicity, thereby creating a conceptual incongruity between the flow equations and thermodynamic equation of state. Here the flow is solved by generalisation of the classic Darcy-Weisbach equation for an incompressible steady flow in a pipe to an ordinary differential equation, permitting continuous variation of density, viscosity and related fluid parameters, as well as head loss or gain due to gravity, in isothermal flow. The differential equation is solved analytically in the case of ideal gas for a single edge in the network. Thereafter the solution is used in an algorithm developed to construct the flow equations automatically for a network characterised by an incidence matrix, and determine pressure distribution, flow rates and all associated parameters therein.

Web-Based Interventions for Weight Loss or Weight Loss Maintenance in Overweight and Obese People: A Systematic Review of Systematic Reviews

PubMed Central

Sorgente, Angela; Manzoni, Gian Mauro; Re, Federica; Simpson, Susan; Perona, Sara; Rossi, Alessandro; Cattivelli, Roberto; Innamorati, Marco; Jackson, Jeffrey B; Castelnuovo, Gianluca

2017-01-01

Background Weight loss is challenging and maintenance of weight loss is problematic. Web-based programs offer good potential for delivery of interventions for weight loss or weight loss maintenance. However, the precise impact of Web-based weight management programs is still unclear. Objective The purpose of this meta-systematic review was to provide a comprehensive summary of the efficacy of Web-based interventions for weight loss and weight loss maintenance. Methods Electronic databases were searched for systematic reviews and meta-analyses that included at least one study investigating the effect of a Web-based intervention on weight loss and/or weight loss maintenance among samples of overweight and/or obese individuals. Twenty identified reviews met the inclusion criteria. The Revised Assessment of Multiple SysTemAtic Reviews (R-AMSTAR) was used to assess methodological quality of reviews. All included reviews were of sufficient methodological quality (R-AMSTAR score ≥22). Key methodological and outcome data were extracted from each review. Results Web-based interventions for both weight loss and weight loss maintenance were more effective than minimal or control conditions. However, when contrasted with comparable non-Web-based interventions, results were less consistent across reviews. Conclusions Overall, the efficacy of weight loss maintenance interventions was stronger than the efficacy of weight loss interventions, but further evidence is needed to more clearly understand the efficacy of both types of Web-based interventions. Trial Registration PROSPERO 2015: CRD42015029377; http://www.crd.york.ac.uk/PROSPERO/display_record.asp? ID=CRD42015029377 (Archived by WebCite at http://www.webcitation.org/6qkSafdCZ) PMID:28652225

Promoting weight loss methods in parenting magazines: Implications for women.

PubMed

Basch, Corey H; Roberts, Katherine J; Samayoa-Kozlowsky, Sandra; Glaser, Debra B

2016-01-01

Weight gain before and after pregnancy is important for women's health. The purpose of this study was to assess articles and advertisements related to weight loss in three widely read parenting magazines, "Parenting School Years," "Parenting Early Years," and "Parenting," which have an estimated combined readership of approximately 24 million (mainly women readers). Almost a quarter (23.7%, n = 32) of the 135 magazine issues over a four year period included at least one feature article on weight loss. A variety of topics were covered in the featured articles, with the most frequent topics being on losing weight to please yourself (25.2%), healthy ways to lose weight (21.1%), and how to keep the weight off (14.7%). Less than half (45.9%) of the articles displayed author credentials, such as their degree, qualifications, or expertise. A fifth (20.0%, n = 27) of the magazines included at least one prominent advertisement for weight loss products. Almost half (46.9%) of the weight loss advertisements were for weight loss programs followed by weight loss food products (25.0%), weight loss aids (21.9%), and only 6.2% of the advertisements for weight loss were on fitness. Parenting magazines should advocate for healthy weight loss, including lifestyle changes for sustained health.

Association Between Monetary Deposits and Weight Loss in Online Commitment Contracts

PubMed Central

Lesser, Lenard I.; Thompson, Caroline A.; Luft, Harold S.

2017-01-01

Purpose To examine the characteristics of voluntary online commitment contracts that may be associated with greater weight loss. Design Retrospective analysis of weight loss commitment contracts derived from a company that provides web-based support for personal commitment contracts. Using regression, we analyzed whether percentage weight loss differed between participants who incentivized their contract using monetary deposits and those who did not. Setting Online. Participants Users (N = 3857) who voluntarily signed up online in 2013 for a weight loss contract. Intervention Participants specified their own weight loss goal, time period, and self-reported weekly weight. Deposits were available in the following 3 categories: charity, anticharity (a nonprofit one does not like), or donations made to a friend. Measures Percentage weight loss per week. Analysis Multivariable linear regressions. Results Controlling for several participant and contract characteristics, contracts with anticharity, charity, and friend deposits had greater reported weight loss than nonincentivized contracts. Weight change per week relative to those without deposits was −0.33%, −0.28%, and −0.25% for anti-charity, charity, and friend, respectively (P < 0.001). Contracts without a weight verification method claimed more weight loss than those with verification. Conclusion Voluntary use of commitment contracts may be an effective tool to assist weight loss. Those who choose to use monetary incentives report more weight loss. It is not clear whether this is due to the incentives or higher motivation. PMID:27502832

Weight loss and bone mineral density.

PubMed

Hunter, Gary R; Plaisance, Eric P; Fisher, Gordon

2014-10-01

Despite evidence that energy deficit produces multiple physiological and metabolic benefits, clinicians are often reluctant to prescribe weight loss in older individuals or those with low bone mineral density (BMD), fearing BMD will be decreased. Confusion exists concerning the effects that weight loss has on bone health. Bone density is more closely associated with lean mass than total body mass and fat mass. Although rapid or large weight loss is often associated with loss of bone density, slower or smaller weight loss is much less apt to adversely affect BMD, especially when it is accompanied with high intensity resistance and/or impact loading training. Maintenance of calcium and vitamin D intake seems to positively affect BMD during weight loss. Although dual energy X-ray absorptiometry is normally used to evaluate bone density, it may overestimate BMD loss following massive weight loss. Volumetric quantitative computed tomography may be more accurate for tracking bone density changes following large weight loss. Moderate weight loss does not necessarily compromise bone health, especially when exercise training is involved. Training strategies that include heavy resistance training and high impact loading that occur with jump training may be especially productive in maintaining, or even increasing bone density with weight loss.

Proven Weight Loss Methods

MedlinePlus

Fact Sheet Proven Weight Loss Methods What can weight loss do for you? Losing weight can improve your health in a number of ways. It can lower ... at www.hormone.org/Spanish . Proven Weight Loss Methods Fact Sheet www.hormone.org

Ain't no mountain high enough? Setting high weight loss goals predict effort and short-term weight loss.

PubMed

De Vet, Emely; Nelissen, Rob M A; Zeelenberg, Marcel; De Ridder, Denise T D

2013-05-01

Although psychological theories outline that it might be beneficial to set more challenging goals, people attempting to lose weight are generally recommended to set modest weight loss goals. The present study explores whether the amount of weight loss individuals strive for is associated with more positive psychological and behavioral outcomes. Hereto, 447 overweight and obese participants trying to lose weight completed two questionnaires with a 2-month interval. Many participants set goals that could be considered unrealistically high. However, higher weight loss goals did not predict dissatisfaction but predicted more effort in the weight loss attempt, as well as more self-reported short-term weight loss when baseline commitment and motivation were controlled for.

Weight Loss and Coronary Heart Disease: Sensitivity Analysis for Unmeasured Confounding by Undiagnosed Disease.

PubMed

Danaei, Goodarz; Robins, James M; Young, Jessica G; Hu, Frank B; Manson, JoAnn E; Hernán, Miguel A

2016-03-01

Evidence for the effect of weight loss on coronary heart disease (CHD) or mortality has been mixed. The effect estimates can be confounded due to undiagnosed diseases that may affect weight loss. We used data from the Nurses' Health Study to estimate the 26-year risk of CHD under several hypothetical weight loss strategies. We applied the parametric g-formula and implemented a novel sensitivity analysis for unmeasured confounding due to undiagnosed disease by imposing a lag time for the effect of weight loss on chronic disease. Several sensitivity analyses were conducted. The estimated 26-year risk of CHD did not change under weight loss strategies using lag times from 0 to 18 years. For a 6-year lag time, the risk ratios of CHD for weight loss compared with no weight loss ranged from 1.00 (0.99, 1.02) to 1.02 (0.99, 1.05) for different degrees of weight loss with and without restricting the weight loss strategy to participants with no major chronic disease. Similarly, no protective effect of weight loss was estimated for mortality risk. In contrast, we estimated a protective effect of weight loss on risk of type 2 diabetes. We estimated that maintaining or losing weight after becoming overweight or obese does not reduce the risk of CHD or death in this cohort of middle-age US women. Unmeasured confounding, measurement error, and model misspecification are possible explanations but these did not prevent us from estimating a beneficial effect of weight loss on diabetes.

Thermogravimetric investigation of the co-combustion between the pyrolysis oil distillation residue and lignite.

PubMed

Li, Hao; Xia, Shuqian; Ma, Peisheng

2016-10-01

Co-combustion of lignite with distillation residue derived from rice straw pyrolysis oil was investigated by non-isothermal thermogravimetric analysis (TGA). The addition of distillation residue improved the reactivity and combustion efficiency of lignite, such as increasing the weight loss rate at peak temperature and decreasing the burnout temperature and the total burnout. With increasing distillation residue content in the blended fuels, the synergistic interactions between distillation residue and lignite firstly increased and then decreased during co-combustion stage. Results of XRF, FTIR, (13)C NMR and SEM analysis indicated that chemical structure, mineral components and morphology of samples have great influence on the synergistic interactions. The combustion mechanisms and kinetic parameters were calculated by the Coats Redfern model, suggesting that the lowest apparent activation energy (120.19kJ/mol) for the blended fuels was obtained by blending 60wt.% distillation residue during main co-combustion stage. Copyright © 2016 Elsevier Ltd. All rights reserved.

Task-specific ionic liquid as a new green inhibitor of mild steel corrosion

NASA Astrophysics Data System (ADS)

Kowsari, E.; Payami, M.; Amini, R.; Ramezanzadeh, B.; Javanbakht, M.

2014-01-01

The corrosion inhibition effects of an imidazolium-based task specific ionic liquid (TSIL) were investigated on a low carbon steel in 1 M HCl solution. Samples were exposed to 1 M HCl solution without and with different concentrations of TSIL. Weight loss measurements, potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), atomic force microscope (AFM) and contact angle measurements were utilized to investigate the inhibition effects of TSIL. The results obtained from the polarization studies revealed that both the anodic and cathodic branches slopes affected in the presence of TSIL. It was shown that TSIL behaved as a mixed type inhibitor with a dominant effect on the anodic reaction rate depression. It was shown that the increase in polarization resistance and the decrease in corrosion current density were more pronounced using 100 mg/L of TSIL after 2 h immersion time. It was also shown that the adsorption of TSIL followed a Langmuir adsorption isotherm.

Durability and synergistic effects of KI on the acid corrosion inhibition of mild steel by hydroxypropyl methylcellulose.

PubMed

Arukalam, I O

2014-11-04

The performance of hydroxypropyl methylcellulose (HPMC) as safe corrosion inhibitor for mild steel in aerated 0.5M H2SO4 solution was appraised by weight loss, impedance and polarization measurements. Results indicate that HPMC functions as a good inhibitor in the studied environment and inhibition efficiency increased with increasing concentration of inhibitor and temperature. Time-dependent effect of the inhibition efficiency reveals that inhibition efficiency increased with time up to the fourth day after which it waned, but improved on addition of KI. The synergism parameter evaluated confirmed the synergistic effect of KI and HPMC. Impedance results clearly show that HPMC inhibited the corrosion reaction via adsorption onto the metal/solution interface following Freundlich adsorption isotherm. Polarization results indicate that HPMC acts as a mixed-type inhibitor with predominant cathodic effect. Theoretical study using density functional theory was employed to establish the correlation between the structure (molecular and electronic) and the inhibition efficiency. Copyright © 2014. Published by Elsevier Ltd.

Performance evaluation of pectin as ecofriendly corrosion inhibitor for X60 pipeline steel in acid medium: experimental and theoretical approaches.

PubMed

Umoren, Saviour A; Obot, Ime B; Madhankumar, A; Gasem, Zuhair M

2015-06-25

The corrosion inhibition effect of pectin (a biopolymer) for X60 pipeline steel in HCl medium was investigated using weight loss, electrochemical, water contact angle measurements, and scanning electron microscopy techniques. The results obtained show that pectin acts as a good corrosion inhibitor for X60 steel. Inhibition efficiency increased with increase in pectin concentration and temperature. Potentiodynamic polarization results reveal that pectin could be classified as a mixed-type corrosion inhibitor with predominant control of the cathodic reaction. The effective corrosion inhibition potential of pectin could be related to the adsorption of pectin molecules at the metal/solution interface which is found to accord with the Langmuir adsorption isotherm model and a protective film formation. Quantum chemical calculations provided insights into the active sites and reactivity parameters governing pectin activity as a good corrosion inhibitor for X60 steel. Copyright © 2015 Elsevier Ltd. All rights reserved.

Weight-loss maintenance for 10 years in the National Weight Control Registry.

PubMed

Thomas, J Graham; Bond, Dale S; Phelan, Suzanne; Hill, James O; Wing, Rena R

2014-01-01

The challenge of weight-loss maintenance is well known, but few studies have followed successful weight losers over an extended period or evaluated the effect of behavior change on weight trajectories. To study the weight-loss trajectories of successful weight losers in the National Weight Control Registry (NWCR) over a 10-year period, and to evaluate the effect of behavior change on weight-loss trajectories. A 10-year observational study of self-reported weight loss and behavior change in 2886 participants (78% female; mean age 48 years) in the NWCR who at entry had lost at least 30 lbs (13.6 kg) and kept it off for at least one year. Data were collected in 1993-2010; analysis was conducted in 2012. Weight loss (kilograms; percent weight loss from maximum weight). Mean weight loss was 31.3 kg (95% CI=30.8, 31.9) at baseline, 23.8 kg (95% CI=23.2, 24.4) at 5 years and 23.1±0.4 kg (95% CI=22.3, 23.9) at 10 years. More than 87% of participants were estimated to be still maintaining at least a 10% weight loss at Years 5 and 10. Larger initial weight losses and longer duration of maintenance were associated with better long-term outcomes. Decreases in leisure-time physical activity, dietary restraint, and frequency of self-weighing and increases in percentage of energy intake from fat and disinhibition were associated with greater weight regain. The majority of weight lost by NWCR members is maintained over 10 years. Long-term weight-loss maintenance is possible and requires sustained behavior change. © 2013 American Journal of Preventive Medicine Published by American Journal of Preventive Medicine All rights reserved.

Effect of weight loss and ketosis on postprandial cholecystokinin and free fatty acid concentrations.

PubMed

Chearskul, Supornpim; Delbridge, Elizabeth; Shulkes, Arthur; Proietto, Joseph; Kriketos, Adamandia

2008-05-01

Weight regain after weight loss may not be due primarily to voluntary return to social habits but may be explained by changes in peripheral hormonal signals activating hunger and encouraging feeding behavior. The objective of this study was to investigate physiologic adaptations to weight loss that may encourage weight regain. The study had a within-subject repeated-measure design [12 healthy, obese men, 33-64 y, body mass index (in kg/m(2)) 30-46] and was a clinical intervention investigation of circulating metabolites and hunger-satiety responses before and after weight loss. Measures included anthropometry (bioelectrical impedance, body weight, and waist circumference), concentrations of circulating hormones and metabolites [ketone bodies, free fatty acids (FFAs), insulin, leptin, glucose, and cholecystokinin (CCK)], and measures of hunger and satiety at baseline, 8 wk after weight loss with a very-low-energy diet, and 1 wk after weight maintenance. Weight loss led to a reduction in postprandial CCK secretion (P = 0.016). However, when subjects were ketotic (elevated circulating beta-hydroxybutyrate concentrations), CCK secretion was sustained at concentrations before weight loss. After weight loss, there were reduced postprandial FFA concentrations (P = 0.0005). The presence of ketosis sustained FFA to concentrations before weight loss (P = 0.60). Rapid weight loss of approximately 10% of initial body weight results in a reduction in postprandial CCK and FFA concentrations.

The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate)

PubMed Central

Arellanes-Lozada, Paulina; Olivares-Xometl, Octavio; Guzmán-Lucero, Diego; Likhanova, Natalya V.; Domínguez-Aguilar, Marco A.; Lijanova, Irina V.; Arce-Estrada, Elsa

2014-01-01

Compounds of poly(ionic liquid)s (PILs), derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium) (PImC12), poly(1-vinyl-3-octylimidazolium) (PImC8) and poly(1-vinyl-3-butylimidazolium) (PImC4) hexafluorophosphate) were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1–1 M H2SO4) by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir’s isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC12 > PImC8 > PImC4) to reach 61% for PImC12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs’ partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions. PMID:28788156

The Tracking Study: Description of a randomized controlled trial of variations on weight tracking frequency in a behavioral weight loss program

PubMed Central

Linde, Jennifer A.; Jeffery, Robert W.; Crow, Scott J.; Brelje, Kerrin L.; Pacanowski, Carly R.; Gavin, Kara L.; Smolenski, Derek J.

2014-01-01

Observational evidence from behavioral weight control trials and community studies suggests that greater frequency of weighing oneself, or tracking weight, is associated with better weight outcomes. Conversely, it has also been suggested that frequent weight tracking may have a negative impact on mental health and outcomes during weight loss, but there are minimal experimental data that address this concern in the context of an active weight loss program. To achieve the long-term goal of strengthening behavioral weight loss programs, the purpose of this randomized controlled trial (the Tracking Study) is to test variations on frequency of self-weighing during a behavioral weight loss program, and to examine psychosocial and mental health correlates of weight tracking and weight loss outcomes. Three hundred thirty-nine overweight and obese adults were recruited and randomized to one of three variations on weight tracking frequency during a 12-month weight loss program with a 12-month follow-up: daily weight tracking, weekly weight tracking, or no weight tracking. The primary outcome is weight in kilograms at 24 months. The weight loss program integrates each weight tracking instruction with standard behavioral weight loss techniques (goal setting, self-monitoring, stimulus control, dietary and physical activity enhancements, lifestyle modifications); participants in weight tracking conditions were provided with wireless Internet technology (Wi-Fi-enabled digital scales and touchscreen personal devices) to facilitate weight tracking during the study. This paper describes the study design, intervention features, recruitment, and baseline characteristics of participants enrolled in the Tracking Study. PMID:25533727

Who succeeds in maintaining weight loss? A conceptual review of factors associated with weight loss maintenance and weight regain.

PubMed

Elfhag, K; Rössner, S

2005-02-01

Weight loss is difficult to achieve and maintaining the weight loss is an even greater challenge. The identification of factors associated with weight loss maintenance can enhance our understanding for the behaviours and prerequisites that are crucial in sustaining a lowered body weight. In this paper we have reviewed the literature on factors associated with weight loss maintenance and weight regain. We have used a definition of weight maintenance implying intentional weight loss that has subsequently been maintained for at least 6 months. According to our review, successful weight maintenance is associated with more initial weight loss, reaching a self-determined goal weight, having a physically active lifestyle, a regular meal rhythm including breakfast and healthier eating, control of over-eating and self-monitoring of behaviours. Weight maintenance is further associated with an internal motivation to lose weight, social support, better coping strategies and ability to handle life stress, self-efficacy, autonomy, assuming responsibility in life, and overall more psychological strength and stability. Factors that may pose a risk for weight regain include a history of weight cycling, disinhibited eating, binge eating, more hunger, eating in response to negative emotions and stress, and more passive reactions to problems.

The relationship between pretreatment dietary composition and weight loss during a randomised trial of different diet approaches.

PubMed

McVay, M A; Jeffreys, A S; King, H A; Olsen, M K; Voils, C I; Yancy, W S

2015-02-01

Identifying pretreatment dietary habits that are associated with weight-loss intervention outcomes could help guide individuals' selection of weight-loss approach among competing options. A pretreatment factor that may influence weight-loss outcomes is macronutrient intake. Overweight and obese Durham Veterans Affairs outpatients were randomised to a weight-loss intervention with a low-carbohydrate diet (n = 71) or orlistat medication therapy plus a low-fat diet (n = 73). Percentage fat, carbohydrate and protein intake prior to treatment were measured using 4-day food records. Linear mixed-effects models were used to determine whether pretreatment percentage macronutrient intake influenced weight trajectories and weight loss in each weight-loss condition. Participant's mean age was 53 years, baseline body mass index was 39.3 kg m(-2) and 72% were male. A higher pretreatment percentage carbohydrate intake was associated with less rapid initial weight loss (P = 0.02) and less rapid weight regain (P = 0.03) in the low-carbohydrate diet condition but was not associated with weight trajectories in the orlistat plus low-fat diet condition. In both conditions, a higher pretreatment percentage fat intake was associated with more rapid weight regain (P < 0.01). Pretreatment percentage protein intake was not associated with weight trajectories. None of the pretreatment macronutrients were associated with weight loss on study completion in either condition. Selection of a weight-loss approach on the basis of pretreatment macronutrient intake is unlikely to improve weight outcomes at the end of a 1-year treatment. However, pretreatment macronutrient intake may have implications for tailoring of interventions to slow weight regain after weight loss. © 2013 The British Dietetic Association Ltd.

Can you trust the parametric standard errors in nonlinear least squares? Yes, with provisos.

PubMed

Tellinghuisen, Joel

2018-04-01

Questions about the reliability of parametric standard errors (SEs) from nonlinear least squares (LS) algorithms have led to a general mistrust of these precision estimators that is often unwarranted. The importance of non-Gaussian parameter distributions is illustrated by converting linear models to nonlinear by substituting e A , ln A, and 1/A for a linear parameter a. Monte Carlo (MC) simulations characterize parameter distributions in more complex cases, including when data have varying uncertainty and should be weighted, but weights are neglected. This situation leads to loss of precision and erroneous parametric SEs, as is illustrated for the Lineweaver-Burk analysis of enzyme kinetics data and the analysis of isothermal titration calorimetry data. Non-Gaussian parameter distributions are generally asymmetric and biased. However, when the parametric SE is <10% of the magnitude of the parameter, both the bias and the asymmetry can usually be ignored. Sometimes nonlinear estimators can be redefined to give more normal distributions and better convergence properties. Variable data uncertainty, or heteroscedasticity, can sometimes be handled by data transforms but more generally requires weighted LS, which in turn require knowledge of the data variance. Parametric SEs are rigorously correct in linear LS under the usual assumptions, and are a trustworthy approximation in nonlinear LS provided they are sufficiently small - a condition favored by the abundant, precise data routinely collected in many modern instrumental methods. Copyright © 2018 Elsevier B.V. All rights reserved.

Do more specific plans help you lose weight? Examining the relationship between plan specificity, weight loss goals, and plan content in the context of a weight management programme.

PubMed

Dombrowski, Stephan U; Endevelt, Ronit; Steinberg, David M; Benyamini, Yael

2016-11-01

The conditions under which planning for behaviour change is most effective are not fully understood. In the context of a weight management programme, we examined the interrelationship between plan specificity, type of behaviour planned (diet vs. exercise), and weight loss goals. Prospective design and content analysis of plans formed by participants of a 10-week weight management programme. Participants (n = 239) formulated two plans, for dietary and exercise behaviours, respectively. Plans were rated for specificity by examining the number of plan components. Weight loss goals were assessed by asking how much weight participants intend to lose. Weight was measured objectively each of the 10 weeks. Changes in body mass index (BMI) over time and the interactions between plan specificity and weight loss goals, for all plans and separately for diet and exercise, were estimated using linear mixed models. Plan specificity was unrelated to weight loss, but interacted with weight loss goals in predicting linear change in BMI (t = -2.48): More specific plans were associated with higher decreases in weight in participants with high weight loss goals. Separate interaction tests for plans formulated for diet and exercise change showed that more specific dietary plans, but not exercise plans, were associated with higher decreases in weight in participants with high weight loss goals (t = -2.21). Within a population that is highly motivated to lose weight, the combination of high weight loss goals and formulating detailed plans for changing dietary behaviours may be most effective in supporting weight loss. Statement of contribution What is already known on this subject? More specific plans are associated with increased performance of health-related behaviours. More motivated individuals form more specific plans. The interrelationship between plan specificity, plan content and behaviour-related goals in relation intervention effectiveness has not been explored to date. What does this study add? The effectiveness of forming specific plans may depend on the strength of behaviour-related goals as well as the behaviour selected for change. More detailed plans, in particular dietary plans, were related to greater weight loss, but only for participants with higher initial weight loss goals. Detailed exercise plans were not associated with weight loss, regardless of initial weight loss goals. © 2016 The British Psychological Society.

Preoperative weight loss with glucagon-like peptide-1 receptor agonist treatment predicts greater weight loss achieved by the combination of medical weight management and bariatric surgery in patients with type 2 diabetes: A longitudinal analysis.

PubMed

Tang, Tien; Abbott, Sally; le Roux, Carel W; Wilson, Violet; Singhal, Rishi; Bellary, Srikanth; Tahrani, Abd A

2018-03-01

We examined the relationship between weight changes after preoperative glucagon-like peptide-1 receptor agonist (GLP-1RA) treatment and weight changes from the start of medical weight management (MWM) until 12 months after bariatric surgery in patients with type 2 diabetes in a retrospective cohort study. A total of 45 patients (64.4% women, median [interquartile range] age 49 [45-60] years) were included. The median (interquartile range) weight loss from start of MWM until 12 months post-surgery was 17.9% (13.0%-29.3%). GLP-1RA treatment during MWM resulted in 5.0% (1.9%-7.7%) weight loss. Weight loss during GLP-1RA treatment predicted weight loss from the start of MWM until 12 months post-surgery, but not postoperative weight loss after adjustment. The proportion of weight loss from start of MWM to 12 months post-surgery attributed to GLP-1RA treatment was negatively associated with that attributed to surgery, after adjustment. In conclusion, weight change after GLP-1RA treatment predicted the weight loss achieved by a combination of MWM and bariatric surgery, but not weight loss induced by surgery only. Failure to lose weight after GLP-1RA treatment should not be considered a barrier to undergoing bariatric surgery. © 2017 John Wiley & Sons Ltd.

Preoperative fat-free mass: a predictive factor of weight loss after gastric bypass.

PubMed

Robert, Maud; Pelascini, Elise; Disse, Emmanuel; Espalieu, Philippe; Poncet, Gilles; Laville, Martine; Gouillat, Christian

2013-04-01

Weight loss failure occurs in 8% to 40% of patients after gastric bypass (GBP). The aim of our study was to analyse the predictive factors of weight loss at 1 year so as to select the best candidates for this surgery and reduce the failures. We included 73 patients treated by laparoscopic GBP. We retrospectively analysed the predictive factors of weight loss in kilograms as well as excess weight loss in percentage (EWL%) at 1 year. The population was divided into tertiles so as to compare the sub-group with the highest weight loss with the sub-group with the least satisfactory results. The significantly predictive factors of a better weight loss in kilograms were male, higher initial weight (144 versus 118 kg, p = 0.002), a significant early weight loss and a higher preoperative percentage of fat-free mass (FFM%; p = 0.03). A higher FFM% was also associated with a better EWL% (p = 0.004). The preoperative FFM (in kilograms) was the principal factor accounting for the weight loss at 1 year regardless of age, gender, height and initial body mass index (BMI; p < 0.0001). There was a better correlation between FFM and weight loss (Spearman test, p = 0.0001) than between initial BMI and weight loss (p = 0.016). We estimated weight loss at 1 year according to initial FFM using the formula: 0.5 kg of lost weight per kilogram of initial FFM. The initial FFM appears to be a decisive factor in the success of GBP. Thus, the sarcopoenic patients would appear to be less suitable candidates for this surgery.

Models of energy homeostasis in response to maintenance of reduced body weight

PubMed Central

Rosenbaum, Michael; Leibel, Rudolph L.

2016-01-01

Objective To test 3 proposed models for adaptive thermogenesis in compartments of energy expenditure following different degrees of weight loss. Specifically, 1.) There is no adaptive thermogenesis (constant relationship of energy expenditure (EE) to metabolic mass). 2.) There is a fixed degree of adaptive thermogenesis once fat stores are below a “threshold”. 3.) The degree of adaptive thermogenesis is proportional to weight loss. Methods The relationship between weight loss and EE was examined in seventeen weight stable in-patient subjects with obesity studied at usual weight and again following a 10% and a 20% weight loss. Results Following initial weight loss (10%), resting (REE) and non-resting (NREE) EE were significantly below those predicted on the basis of the amount and composition of weight lost. Further reductions below predicted values of NREE but not REE occurred following an additional 10% weight loss. Changes in body weight, composition, and/or energy stores were significantly correlated with changes in EE. Conclusion All models are applicable to the decline in EE following weight loss. The disproportionate decline in REE is consistent with a threshold model (no change with further weight loss) while the disproportionate decline in NREE is largely reflective of the degree of weight loss. PMID:27460711

Short-term weight loss attenuates local tissue inflammation and improves insulin sensitivity without affecting adipose inflammation in obese mice.

PubMed

Jung, Dae Young; Ko, Hwi Jin; Lichtman, Eben I; Lee, Eunjung; Lawton, Elizabeth; Ong, Helena; Yu, Kristine; Azuma, Yoshihiro; Friedline, Randall H; Lee, Ki Won; Kim, Jason K

2013-05-01

Obesity is a major cause of insulin resistance, and weight loss is shown to improve glucose homeostasis. But the underlying mechanism and the role of inflammation remain unclear. Male C57BL/6 mice were fed a high-fat diet (HFD) for 12 wk. After HFD, weight loss was induced by changing to a low-fat diet (LFD) or exercise with continuous HFD. The weight loss effects on energy balance and insulin sensitivity were determined using metabolic cages and hyperinsulinemic euglycemic clamps in awake mice. Diet and exercise intervention for 3 wk caused a modest weight loss and improved glucose homeostasis. Weight loss dramatically reduced local inflammation in skeletal muscle, liver, and heart but not in adipose tissue. Exercise-mediated weight loss increased muscle glucose metabolism without affecting Akt phosphorylation or lipid levels. LFD-mediated weight loss reduced lipid levels and improved insulin sensitivity selectively in liver. Both weight loss interventions improved cardiac glucose metabolism. These results demonstrate that a short-term weight loss with exercise or diet intervention attenuates obesity-induced local inflammation and selectively improves insulin sensitivity in skeletal muscle and liver. Our findings suggest that local factors, not adipose tissue inflammation, are involved in the beneficial effects of weight loss on glucose homeostasis.

Sex differences in the relation of weight loss self-efficacy, binge eating, and depressive symptoms to weight loss success in a residential obesity treatment program.

PubMed

Presnell, Katherine; Pells, Jennifer; Stout, Anna; Musante, Gerard

2008-04-01

The aim of the current study was to examine whether weight loss self-efficacy, binge eating, and depressive symptoms predicted weight loss during treatment, and whether gender moderates these associations with prospective data from 297 participants (223 women and 74 men) enrolled in a residential obesity treatment program. Men reported higher initial levels of self-efficacy than women, whereas women reported greater pre-treatment levels of binge eating and depressive symptoms. Higher pre-treatment levels of weight control self-efficacy, binge eating, and depressive symptoms predicted greater weight loss in men, but not in women. Results suggest that certain psychological and behavioral factors should be considered when implementing weight loss interventions, and indicate a need to consider gender differences in predictors of weight loss treatment. Future research should seek to identify predictors of weight loss among women.

Outcomes and Utilization of a Low Intensity Workplace Weight Loss Program

PubMed Central

Carpenter, Kelly M.; Lovejoy, Jennifer C.; Lange, Jane M.; Hapgood, Jenny E.; Zbikowski, Susan M.

2014-01-01

Obesity is related to high health care costs and lost productivity in the workplace. Employers are increasingly sponsoring weight loss and wellness programs to ameliorate these costs. We evaluated weight loss outcomes, treatment utilization, and health behavior change in a low intensity phone- and web-based, employer-sponsored weight loss program. The intervention included three proactive counseling phone calls with a registered dietician and a behavioral health coach as well as a comprehensive website. At six months, one third of those who responded to the follow-up survey had lost a clinically significant amount of weight (≥5% of body weight). Clinically significant weight loss was predicted by the use of both the counseling calls and the website. When examining specific features of the web site, the weight tracking tool was the most predictive of weight loss. Health behavior changes such as eating more fruits and vegetables, increasing physical activity, and reducing stress were all predictive of clinically significant weight loss. Although limited by the low follow-up rate, this evaluation suggests that even low intensity weight loss programs can lead to clinical weight loss for a significant number of participants. PMID:24688791

Predictors of long-term weight loss in adults with modest initial weight loss, by sex and race.

PubMed

Svetkey, Laura P; Ard, Jamy D; Stevens, Victor J; Loria, Catherine M; Young, Deb Y; Hollis, Jack F; Appel, Lawrence J; Brantley, Phillip J; Kennedy, Betty M; Kumanyika, Shiriki K; Batch, Bryan C; Corsino, Leonor; Lien, Lillian F; Vollmer, William M

2012-09-01

Effective weight management interventions could reduce race-sex disparities in cardiovascular disease (CVD), yet little is known about factors associated with successful weight loss maintenance in race-sex subgroups. In the Weight Loss Maintenance trial (WLM), overweight/obese (BMI 25-45 kg/m(2)) adults who lost ≥4 kg in a 6-month behavioral weight loss intervention (phase I) were randomized into one of three 30-month maintenance interventions (phase II). To investigate predictors in subgroups, randomized groups were combined for this analysis. Of 1,685 phase I participants, 1,032 (61%) entered phase II, including 12% black men (BM), 26% black women (BW), 25% white men (WM), and 37% white women (WW). Weight change over the 36-month study ranged from -2.3% (95% confidence interval = -3.1 to -1.5%) in BW to -4.5% (95% confidence interval = -5.7 to -4.0%) in WM, the result of differential weight loss during phase I. Within race, men lost significantly more weight than women, but within sex group, weight loss did not differ significantly between races. Although participants regained weight during phase II, regain did not differ by race-sex group, and mean weight at the end of the study was significantly lower than phase I entry weight for each subgroup. In regression models, phase I weight loss predicted overall 36-month weight loss in all race-sex groups. Healthy dietary pattern at entry, improvement in dietary pattern, or both were predictive in three of four race-sex groups. Few other variables other than initial weight loss and dietary pattern were predictive. Future research should identify additional modifiable influences on long-term maintenance after a modest weight loss.

Clozapine-associated weight loss.

PubMed

Hanwella, R; de Silva, V; Wijeratne, C; Ketharanathan, T; de Silva, J

2010-07-01

Clozapine is associated with weight gain. We report three patients with substantial weight loss following treatment with clozapine. The weight loss observed in the three patients was 33, 18 and 14.4 kg with percentage loss of body weight of 49, 18 and 21 respectively. Two patients had diabetes mellitus. History, physical examination and extensive investigations in the three patients did not reveal any cause that could account for the weight loss.

Energy homeostasis and appetite regulating hormones as predictors of weight loss in men and women.

PubMed

Williams, Rebecca L; Wood, Lisa G; Collins, Clare E; Morgan, Philip J; Callister, Robin

2016-06-01

Sex differences in weight loss are often seen despite using the same weight loss program. There has been relatively little investigation of physiological influences on weight loss success in males and females, such as energy homeostasis and appetite regulating hormones. The aims were to 1) characterise baseline plasma leptin, ghrelin and adiponectin concentrations in overweight and obese males and females, and 2) determine whether baseline concentrations of these hormones predict weight loss in males and females. Subjects were overweight or obese (BMI 25-40 kg/m(2)) adults aged 18-60 years. Weight was measured at baseline, and after three and six months participation in a weight loss program. Baseline concentrations of leptin, adiponectin and ghrelin were determined by enzyme-linked immunosorbent assay (ELISA). An independent t-test or non-parametric equivalent was used to determine any differences between sex. Linear regression determined whether baseline hormone concentrations were predictors of six-month weight change. Females had significantly higher baseline concentrations of leptin, adiponectin and unacylated ghrelin as well as ratios of leptin:adiponectin and leptin:ghrelin. The ratio of acylated:unacylated ghrelin was significantly higher in males. In males and females, a higher baseline concentration of unacylated ghrelin predicted greater weight loss at six months. Additionally in females, higher baseline total ghrelin predicted greater weight loss and a higher ratio of leptin:ghrelin predicted weight gain at six months. A higher pre-weight-loss plasma concentration of unacylated ghrelin is a modest predictor of weight loss success in males and females, while a higher leptin:ghrelin ratio is a predictor of weight loss failure in females. Further investigation is required into what combinations and concentrations of these hormones are optimal for weight loss success. Copyright © 2016 Elsevier Ltd. All rights reserved.

Postnatal weight loss in substitute methadone-exposed infants: implications for the management of breast feeding.

PubMed

Dryden, Carol; Young, David; Campbell, Nicole; Mactier, Helen

2012-05-01

It is widely accepted that maternal drug-exposed infants demonstrate excessive early weight loss, but this has not previously been quantified. Among 354 term, substitute methadone-exposed infants, median maximal weight losses were 10.2% and 8.5% for breast- and formula-fed infants, respectively (p=0.003). Weight loss was less in small for gestational age compared to appropriately grown infants (p<0.001). There was no association between maximal weight loss and plasma sodium concentration (p=0.807). Relative to non-drug exposed infants, weight loss was more marked in formula-fed infants, 48% of whom demonstrated weight loss in excess of the 95th centile (compared to 23% of exclusively breastfed infants; p<0.001). Median weight loss nadir was on day 5, excepting those infants exclusively breastfed (day 4). These data suggest that excessive neonatal weight loss among breastfed infants of drug-misusing mothers does not necessarily reflect poorly established lactation and may help to guide management of breast feeding in this population.

Plasma myostatin is only a weak predictor for weight maintenance in obese adults.

PubMed

Tsioga, M N; Oikonomou, D; Vittas, S; Kalscheuer, H; Roeder, E; Wintgens, K F; Nawroth, P P; Wolfrum, C; Rudofsky, G

2015-09-01

Predicting an individual's success in a non-surgical weight loss approach is a demanding need since obesity is becoming an epidemic burden. A possible predictive marker is myostatin, a member of the transforming growth factor b superfamily, which has been shown to be an important regulator of muscle homeostasis. In the present study, we analyzed myostatin as a marker to predict weight loss of patients that participated in a 2 phased weight reduction program, comprising a weight loss period of 12 weeks and a weight stabilization period of 40 weeks. Therefore, 62 obese individuals with a mean BMI of 40.6 kg/m(2) were included. Plasma myostatin was measured with ELISA at the beginning (T0), after weight loss (T1) and at the end of the program (T2). Although significant weight loss of -23.9±14.9 kg was achieved, myostatin did not change significantly during the program (T0>T1: p=0.46; T1>T2: p=0.70; T0>T2: p=0.57). Myostatin at baseline did neither negatively correlate with the achieved weight loss in the weight reduction phase (T0>T1: r=0.27, p=0.16) nor with weight loss during the whole program (T0>T2: r=0.20, p=0.29). Only a minor correlation with myostatin levels after weight loss with weight regain during maintenance period was detected. (T1>T2: r=-0.37, p=0.05). Plasma myostatin might be suitable in predicting weight regain after marked weight loss, but no association with weight loss was observed in patients undergoing a non-surgical weight loss program. Therefore, myostatin does not seem to be a predictor for success in non-surgical weight loss approaches. © Georg Thieme Verlag KG Stuttgart · New York.

Rebound weight gain as associated with high plasma norepinephrine levels that are mediated through polymorphisms in the beta2-adrenoceptor.

PubMed

Masuo, Kazuko; Katsuya, Tomohiro; Kawaguchi, Hideki; Fu, Yuxiao; Rakugi, Hiromi; Ogihara, Toshio; Tuck, Michael L

2005-11-01

A successful weight loss program is essential treatment for obesity-related diseases, but it is well known that the majority of individuals do not succeed in weight loss maintenance. The present study evaluates hormonal mechanisms and the relationship of beta2-adrenoceptor polymorphisms involved in individuals who regain weight after initially successful weight loss. Overweight Japanese men (n = 154) were enrolled in a 24-month weight loss program. Body mass index (BMI), total body fat mass, plasma norepinephrine (NE) and leptin levels, and beta2-adrenoceptor polymorphisms (Arg16Gly, Gln27Glu) were measured every 6 months for the 24-month period. Maintenance of weight loss was defined as significant weight loss (>or=10% reduction) from entry weight at 6 months and maintenance of the weight loss for an additional 18 months. Rebound weight gain was defined as significant weight loss at 6 months but subsequent regain of body weight during the next 18 months. The results showed that 37 subjects maintained weight loss during 24 months, whereas 36 subjects had rebound weight gain. The BMI at entry and calorie intake and physical activity at each period were similar between the two groups. Subjects who maintained weight loss had at entry a significantly lower fat mass and plasma NE levels compared to those with rebound weight gain. Body fat mass, NE, and leptin levels at entry predicted the degree of change in body weight during the 24-month study period. Subjects with rebound weight gain had a significantly higher frequency of the Gly16 allele for the beta2-adrenoceptor polymorphism compared to subjects who had a 24-month maintenance of weight loss. Subjects carrying the Gly16 allele also had significantly higher plasma NE, leptin, and body fat mass levels and a greater waist-to-hip ratio both at entry and throughout the study. A high initial degree of body fat mass and high plasma NE levels as determined by the Gly16 allele for the beta2-adrenoceptor polymorphisms predict those individuals who will have rebound weight gain after their initial successful weight loss.

Diet quality of breast cancer survivors after a six-month weight management intervention: Improvements and association with weight loss

PubMed Central

Christifano, Danielle N.; Fazzino, Tera L.; Sullivan, Debra A.; Befort, Christie A.

2016-01-01

Purpose Obesity and diet quality are two distinct lifestyle factors associated with morbidity and mortality among breast cancer survivors. The purpose of this study was to examine diet quality changes during a weight loss intervention among breast cancer survivors, and whether diet quality change was an important factor related to weight loss. Methods Participants were overweight/obese breast cancer survivors (n=180) participating in a weight loss intervention. Diet quality scores were calculated using the Healthy Eating Index-2010. Paired sample t-tests were run to examine change in diet quality, and a latent difference model was constructed to examine whether change in diet quality was associated with weight change. Results Participants significantly improved diet quality (p=.001) and lost 13.2%± 5.8% (mean± SD) of their weight (p=.001). Six month HEI score was significantly associated with weight loss, controlling for baseline BMI (p=.003). Improvement in diet quality was also significantly associated with weight loss (p=.01). Conclusion Our findings indicate that a weight loss intervention can result in both clinically significant weight loss and improvement in diet quality, and that improved diet quality is predictive of weight loss. Both weight loss and diet quality are implicated in longevity and quality of life for breast cancer survivors. PMID:27635676

Magnetic vs. non-magnetic colloids - A comparative adsorption study to quantify the effect of dye-induced aggregation on the binding affinity of an organic dye.

PubMed

Williams, Tyler A; Lee, Jenny; Diemler, Cory A; Subir, Mahamud

2016-11-01

Due to attractive magnetic forces, magnetic particles (MPs) can exhibit colloidal instability upon molecular adsorption. Thus, by comparing the dye adsorption isotherms of MPs and non-magnetic particles of the same size, shape and functional group it should be possible to characterize the influence of magnetic attraction on MP aggregation. For a range of particle densities, a comparative adsorption study of malachite green (MG(+)) onto magnetic and non-magnetic colloids was carried out using a combination of a separation technique coupled with UV-vis spectroscopy, optical microscopy, and polarization dependent second harmonic generation (SHG) spectroscopy. Significant MP aggregation occurs in aqueous solution due to MG(+) adsorption. This alters the adsorption isotherm and challenges the determination of the adsorption equilibrium constant, Kads. The dye-induced aggregation is directly related to the MG(+) concentration, [MG(+)]. A modified Langmuir equation, which incorporates loss of surface sites due to this aggregation, accurately describes the resulting adsorption isotherms. The Kads of 1.1 (±0.3)×10(7) and a loss of maximum MP surface capacity of 2.8 (±0.7)×10(3)M(-1) per [MG(+)] has been obtained. Additionally, SHG has been established as an effective tool to detect aggregation in nanoparticles. Copyright © 2016 Elsevier Inc. All rights reserved.

Timing of food intake is associated with weight loss evolution in severe obese patients after bariatric surgery.

PubMed

Ruiz-Lozano, T; Vidal, J; de Hollanda, A; Scheer, F A J L; Garaulet, M; Izquierdo-Pulido, M

2016-12-01

Recent research has demonstrated a relationship between the timing of food intake and weight loss in humans. However, whether the meal timing can be associated with weight loss in patients treated with bariatric surgery is unknown. To evaluate the role of food-timing in the evolution of weight loss in a sample of 270 patients that underwent bariatric surgery with a follow-up of 6 years. Participants (79% women; age [mean ± SD]: 52 ± 11 years; BMI: 46.5 ± 6.0 kg/m 2 ) were classified according their weight loss response patterns after bariatric surgery: good weight-loss-responders (67.8%), primarily poor weight-loss-responders (10.8%) or secondarily poor weight-loss-responders (21.4%). Then, they were grouped in early-eaters and late-eaters, according to the timing of the main meal (before or after 15:00 h). Obesity and biochemical parameters, energy and macronutrients intake, energy expenditure, sleep duration, and chronotype were studied. The percentage of late eaters (after 15:00 h) was significantly higher in the primarily poor weight-loss-responders (∼70%) than in both secondarily poor weight-loss-responders (∼42%) and good weight-loss-responders (∼37%) (p = 0.011). Consistently, primarily poor weight-loss-responders had lunch later as compared to good and secondarily poor weight-loss-responders (p = 0.034). Age, gender and type of surgery were not determining. Surprisingly, obesity-related variables, biochemical parameters, pre-surgical total energy expenditure, sleep duration, chronotype, calorie intake and macronutrients distribution, were similar among groups. Weight loss effectiveness after bariatric surgery is related to the timing of the main meal. Our preliminary results suggest that the timing of food intake is important for weight regulation and that eating at the right time may be a relevant factor to consider in weight loss therapy even after bariatric surgery. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Weight Advice Associated With Male Firefighter Weight Perception and Behavior

PubMed Central

Brown, Austin L.; Poston, Walker S.C.; Jahnke, Sara A.; Haddock, C. Keith; Luo, Sheng; Delclos, George L.; Day, R. Sue

2016-01-01

Introduction The high prevalence of overweight and obesity threatens the health and safety of the fire service. Healthcare professionals may play an important role in helping firefighters achieve a healthy weight by providing weight loss counseling to at-risk firefighters. This study characterizes the impact of healthcare professional weight loss advice on firefighter weight perceptions and weight loss behaviors among overweight and obese male firefighters. Methods A national sample of 763 overweight and obese male firefighters who recalled visiting a healthcare provider in the past 12 months reported information regarding healthcare visits, weight perceptions, current weight loss behaviors, and other covariates in 2011–2012. Analyzed in 2013, four unique multilevel logistic regression models estimated the association between healthcare professional weight loss advice and the outcomes of firefighter-reported weight perceptions, intentions to lose weight, reduced caloric intake, and increased physical activity. Results Healthcare professional weight loss advice was significantly associated with self-perception as overweight (OR=4.78, 95% CI=2.16, 10.57) and attempted weight loss (OR=2.06, 95% CI=1.25, 3.38), but not significantly associated with reduced caloric intake (OR=1.26, 95% CI=0.82, 1.95) and increased physical activity (OR=1.51, 95% CI=0.89, 2.61), after adjusting for confounders. Conclusions Healthcare professional weight loss advice appears to increase the accuracy of firefighter weight perceptions, promote weight loss attempts, and may encourage dieting and physical activity behaviors among overweight firefighters. Healthcare providers should acknowledge their ability to influence the health behaviors of overweight and obese patients and make efforts to increase the quality and frequency of weight loss recommendations for all firefighters. PMID:26141913

Weight Advice Associated With Male Firefighter Weight Perception and Behavior.

PubMed

Brown, Austin L; Poston, Walker S C; Jahnke, Sara A; Haddock, C Keith; Luo, Sheng; Delclos, George L; Day, R Sue

2015-10-01

The high prevalence of overweight and obesity threatens the health and safety of the fire service. Healthcare professionals may play an important role in helping firefighters achieve a healthy weight by providing weight loss counseling to at-risk firefighters. This study characterizes the impact of healthcare professional weight loss advice on firefighter weight perceptions and weight loss behaviors among overweight and obese male firefighters. A national sample of 763 overweight and obese male firefighters who recalled visiting a healthcare provider in the past 12 months reported information regarding healthcare visits, weight perceptions, current weight loss behaviors, and other covariates in 2011-2012. Analyzed in 2013, four unique multilevel logistic regression models estimated the association between healthcare professional weight loss advice and the outcomes of firefighter-reported weight perceptions, intentions to lose weight, reduced caloric intake, and increased physical activity. Healthcare professional weight loss advice was significantly associated with self-perception as overweight (OR=4.78, 95% CI=2.16, 10.57) and attempted weight loss (OR=2.06, 95% CI=1.25, 3.38), but not significantly associated with reduced caloric intake (OR=1.26, 95% CI=0.82, 1.95) and increased physical activity (OR=1.51, 95% CI=0.89, 2.61), after adjusting for confounders. Healthcare professional weight loss advice appears to increase the accuracy of firefighter weight perceptions, promote weight loss attempts, and may encourage dieting and physical activity behaviors among overweight firefighters. Healthcare providers should acknowledge their ability to influence the health behaviors of overweight and obese patients and make efforts to increase the quality and frequency of weight loss recommendations for all firefighters. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Does the Method of Weight Loss Effect Long-Term Changes in Weight, Body Composition or Chronic Disease Risk Factors in Overweight or Obese Adults? A Systematic Review

PubMed Central

Washburn, Richard A.; Szabo, Amanda N.; Lambourne, Kate; Willis, Erik A.; Ptomey, Lauren T.; Honas, Jeffery J.; Herrmann, Stephen D.; Donnelly, Joseph E.

2014-01-01

Background Differences in biological changes from weight loss by energy restriction and/or exercise may be associated with differences in long-term weight loss/regain. Objective To assess the effect of weight loss method on long-term changes in weight, body composition and chronic disease risk factors. Data Sources PubMed and Embase were searched (January 1990-October 2013) for studies with data on the effect of energy restriction, exercise (aerobic and resistance) on long-term weight loss. Twenty articles were included in this review. Study Eligibility Criteria Primary source, peer reviewed randomized trials published in English with an active weight loss period of >6 months, or active weight loss with a follow-up period of any duration, conducted in overweight or obese adults were included. Study Appraisal and Synthesis Methods Considerable heterogeneity across trials existed for important study parameters, therefore a meta-analysis was considered inappropriate. Results were synthesized and grouped by comparisons (e.g. diet vs. aerobic exercise, diet vs. diet + aerobic exercise etc.) and study design (long-term or weight loss/follow-up). Results Forty percent of trials reported significantly greater long-term weight loss with diet compared with aerobic exercise, while results for differences in weight regain were inconclusive. Diet+aerobic exercise resulted in significantly greater weight loss than diet alone in 50% of trials. However, weight regain (∼55% of loss) was similar in diet and diet+aerobic exercise groups. Fat-free mass tended to be preserved when interventions included exercise. PMID:25333384

The effects of water and non-nutritive sweetened beverages on weight loss and weight maintenance: A randomized clinical trial.

PubMed

Peters, John C; Beck, Jimikaye; Cardel, Michelle; Wyatt, Holly R; Foster, Gary D; Pan, Zhaoxing; Wojtanowski, Alexis C; Vander Veur, Stephanie S; Herring, Sharon J; Brill, Carrie; Hill, James O

2016-02-01

To evaluate the effects of water versus beverages sweetened with non-nutritive sweeteners (NNS) on body weight in subjects enrolled in a year-long behavioral weight loss treatment program. The study used a randomized equivalence design with NNS or water beverages as the main factor in a trial among 303 weight-stable people with overweight and obesity. All participants participated in a weight loss program plus assignment to consume 24 ounces (710 ml) of water or NNS beverages daily for 1 year. NNS and water treatments were non-equivalent, with NNS treatment showing greater weight loss at the end of 1 year. At 1 year subjects receiving water had maintained a 2.45 ± 5.59 kg weight loss while those receiving NNS beverages maintained a loss of 6.21 ± 7.65 kg (P < 0.001 for difference). Water and NNS beverages were not equivalent for weight loss and maintenance during a 1-year behavioral treatment program. NNS beverages were superior for weight loss and weight maintenance in a population consisting of regular users of NNS beverages who either maintained or discontinued consumption of these beverages and consumed water during a structured weight loss program. These results suggest that NNS beverages can be an effective tool for weight loss and maintenance within the context of a weight management program. © 2015 The Authors, Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS).

Bone, body weight, and weight reduction: what are the concerns?

PubMed

Shapses, Sue A; Riedt, Claudia S

2006-06-01

Of the U.S. population, 65% is either overweight or obese, and weight loss is recommended to reduce co-morbid conditions. However, bone mobilization and loss may also occur with weight loss. The risk for bone loss depends on initial body weight, age, gender, physical activity, and conditions of dieting such as the extent of energy restriction and specific levels of nutrient intake. Older populations are more prone to bone loss with weight loss; in women, this is due at least in part to a reduced dietary Ca intake and/or efficiency of absorption. Potential hormonal mechanisms regulating bone loss during weight loss are discussed, including decreases in estrogen, leptin, glucagon-like peptide-2, growth hormone, and insulin-like growth factor-1, or an increase in cortisol. In contrast, the rise in adiponectin and ghrelin with weight reduction should not be detrimental to bone. Combining energy restriction with exercise does not necessarily prevent bone loss, but may attenuate loss as was shown with additional Ca intake or osteoporosis medications. Future controlled weight loss trials should be designed to further address mechanisms influencing the density and quality of bone sites vulnerable to fracture, in the prevention of osteoporosis.

3 Steps for Setting Healthy Eating Goals

Cancer.gov

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Commercial programs' online weight loss claims as compared to results from randomized controlled trials

PubMed Central

Vakil, Rachit M.; Chaudhry, Zoobia W.; Doshi, Ruchi S.; Clark, Jeanne M.; Gudzune, Kimberly A.

2017-01-01

Objective To characterize weight-loss claims and disclaimers present on websites for commercial weight-loss programs and compare them to results from published randomized controlled trials (RCT). Methods We performed a content analysis of all homepages and testimonials available on the websites of 24 randomly selected programs. Two team members independently reviewed each page and abstracted information from text and images to capture relevant content including demographics, weight loss, and disclaimers. We performed a systematic review to evaluate the efficacy of these programs by searching MEDLINE and Cochrane Database of Systematic Reviews, and abstracted mean weight change from each included RCT. Results Overall, the amount of weight loss portrayed in the testimonials was extreme across all programs examined (range median weight loss 10.7 to 49.5 kg). Only 10 out of the 24 programs had eligible RCTs. Median weight losses reported in testimonials exceeded that achieved by trial participants. Most programs with RCTs (78%) provided disclaimers stating that the testimonial's results were non-typical and/or giving a range of typical weight loss. Conclusion Weight loss claims within testimonials were higher than results from RCTs. Future studies should examine whether commercial programs' advertising practices influence patients' expectations or satisfaction with modest weight loss results. PMID:28865085

Overweight in polycystic ovary syndrome. An update on evidence based advice on diet, exercise and metformin use for weight loss.

PubMed

Ravn, P; Haugen, A G; Glintborg, D

2013-03-01

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in premenopausal women affecting 5-10%. Nearly 50% are overweight or obese, which result in a more severe phenotype of PCOS. Weight loss is therefore considered the first line treatment in overweight women with PCOS. The aim of this study was to appoint evidence based and clinically applicable advises on weight loss in overweight women with PCOS. A review of the existing literature on weight loss through lifestyle modification and/or metformin treatment in overweight women with PCOS. The primary outcome was weight loss. The clinical manifestations of hyperandrogenism and menstrual cyclicity were secondary outcomes. Metabolic parameters were not included in the present review. Weight loss is most effectively achieved through a 12-1500 kcal/day diet, which results in a clinically relevant weight loss. The type of diet has no implications for degree of weight loss. Physical activity has no significant additive effect on weight loss. Metformin combined with a low calorie diet has subtle additive effect on weight loss and level of androgens when compared to diet alone. Weight loss through life style changes, preferably a low calorie diet, should be the first line treatment in overweight/obese women with PCOS. Metformin can be considered as an additional treatment but has subtle additive effect.

Demographic factors and weight change in a worksite weight loss intervention

USDA-ARS?s Scientific Manuscript database

Worksites are increasingly being considered as locations for weight loss programs. We examined predictors of weight loss in employees participating in a 6 month randomized study of a weight loss intervention versus wait-listed control at 4 worksites (2 for-profit and 2 non-profit). Measures included...

The 371 deg C mechanical properties of graphite/polyimide composites

NASA Technical Reports Server (NTRS)

Delvigs, P.

1985-01-01

A series of condensation polyimides based on pyromellitic dianhydride is synthesized and evaluated for potential application at 371 C. Several three-and four-ring benzenoid diamine systems containing oxygen bridging groups are investigated. Thermomechanical analysis of neat resin specimens indicate that the polyimide prepared from the dimethyl ester of pyrometallitic acid (PMDE) and 2,2-bis4-(4'-aminophenoxy) phenyl]-1,1,1,3,3,3- hexafluoropropane (BDAF) is the only resin system which has a glass transition temperature (Tg) above 371 C. The Tg of the PMDE/BDAF polyimide is found to be 390 C after a postcure air at 371 C for 24 hr. Unidirectional composites are fabricated from the PMDE/BDAF system and unsized Celion 6000 graphite fibers. Final cure temperatures in the range of 371 to 427 C with an applied pressure of 10.34 to 13.78 MPa are investigated. The void content of the composites ranges from 4.6 to 8.6 percent. Composites cured at 399 C under a pressure of 10.34 MPa and postcured in air at 371 C for 24 hr exhibit the highest 371 C interlaminar shear strength (ILSS, 40.7 MPa) and flexural strength (758 MPa). The thermo-oxidative stability of the composites is determined by subjecting specimens to isothermal exposure at 371 C in air at atmospheric pressure, as well as a pressure of 0.52 MPa. Specimens exposed at atmospheric pressure exhibit a weight loss of 12 percent after 200 hr of exposure and 88 percent retention of its original 371 C ILSS. In contrast, the specimens exposed at 0.52 MPa pressure exhibit a comparable weight loss after only 72 hr, and a 71 percent retention of its original 371 C ILSS.

Information processing versus social cognitive mediators of weight loss in a podcast-delivered health intervention.

PubMed

Ko, Linda K; Turner-McGrievy, Gabrielle M; Campbell, Marci K

2014-04-01

Podcasting is an emerging technology, and previous interventions have shown promising results using theory-based podcast for weight loss among overweight and obese individuals. This study investigated whether constructs of social cognitive theory and information processing theories (IPTs) mediate the effect of a podcast intervention on weight loss among overweight individuals. Data are from Pounds off Digitally, a study testing the efficacy of two weight loss podcast interventions (control podcast and theory-based podcast). Path models were constructed (n = 66). The IPTs, elaboration likelihood model, information control theory, and cognitive load theory mediated the effect of a theory-based podcast on weight loss. The intervention was significantly associated with all IPTs. Information control theory and cognitive load theory were related to elaboration, and elaboration was associated with weight loss. Social cognitive theory constructs did not mediate weight loss. Future podcast interventions grounded in theory may be effective in promoting weight loss.

Instrumentalization of Eating Improves Weight Loss Maintenance in Obesity.

PubMed

Christensen, Bodil Just; Iepsen, Eva Winning; Lundgren, Julie; Holm, Lotte; Madsbad, Sten; Holst, Jens Juul; Torekov, Signe Sørensen

2017-01-01

The purpose of this study was to identify psychosocial determinants for maintaining weight loss. 42 obese individuals who achieved a 12% weight loss before entering a 52-week weight maintenance program were interviewed qualitatively. Psychosocial factors related to weight loss maintenance were identified in two contrasting groups: weight reducers and weight regainers. Groups were defined by health-relevant weight maintenance (additional weight loss > 3% at week 52, n = 9 versus weight gain > 3%, at week 52, n = 20). Weight reducers reported structured meal patterns (p = 0.008), no comfort eating (p = 0.016) and less psychosocial stress (p = 0.04) compared to weight regainers. The ability to instrumentalize eating behavior emerged as an important factor (p = 0.007). Nutritional knowledge, motivation or exercise level did not differ between groups (p > 0.05). Successful weight loss maintenance was associated with an interplay between behavioral, affective and contextual changes. 'Instrumentalization of eating behavior' seems to be an important element in long-term weight maintenance. © 2017 The Author(s) Published by S. Karger GmbH, Freiburg.

The efficiency of combustion turbines with constant-pressure combustion

NASA Technical Reports Server (NTRS)

Piening, Werner

1941-01-01

Of the two fundamental cycles employed in combustion turbines, namely, the explosion (or constant-volume) cycle and the constant-pressure cycle, the latter is considered more in detail and its efficiency is derived with the aid of the cycle diagrams for the several cases with adiabatic and isothermal compression and expansion strokes and with and without utilization of the exhaust heat. Account is also taken of the separate efficiencies of the turbine and compressor and of the pressure losses and heat transfer in the piping. The results show that without the utilization of the exhaust heat the efficiencies for the two cases of adiabatic and isothermal compression is offset by the increase in the heat supplied. It may be seen from the curves that it is necessary to attain separate efficiencies of at least 80 percent in order for useful results to be obtained. There is further shown the considerable effect on the efficiency of pressure losses in piping or heat exchangers.

Effect of weight loss in obese dogs on indicators of renal function or disease.

PubMed

Tvarijonaviciute, A; Ceron, J J; Holden, S L; Biourge, V; Morris, P J; German, A J

2013-01-01

Obesity is a common medical disorder in dogs, and can predispose to a number of diseases. Human obesity is a risk factor for the development and progression of chronic kidney disease. To investigate the possible association of weight loss on plasma and renal biomarkers of kidney health. Thirty-seven obese dogs that lost weight were included in the study. Prospective observational study. Three novel biomarkers of renal functional impairment, disease, or both (homocysteine, cystatin C, and clusterin), in addition to traditional markers of chronic renal failure (serum urea and creatinine, urine specific gravity [USG], urine protein-creatinine ratio [UPCR], and urine albumin corrected by creatinine [UAC]) before and after weight loss in dogs with naturally occurring obesity were investigated. Urea (P = .043) and USG (P = .012) were both greater after weight loss than before loss, whilst UPCR, UAC, and creatinine were less after weight loss (P = .032, P = .006, and P = .026, respectively). Homocysteine (P < .001), cystatin C (P < .001) and clusterin (P < .001) all decreased upon weight loss. Multiple linear regression analysis revealed associations between percentage weight loss (greater weight loss, more lean tissue loss; r = -0.67, r(2) = 0.45, P < .001) and before-loss plasma clusterin concentration (greater clusterin, more lean tissue loss; r = 0.48, r(2) = 0.23, P = .003). These results suggest possible subclinical alterations in renal function in canine obesity, which improve with weight loss. Further work is required to determine the nature of these alterations and, most notably, the reason for the association between before loss plasma clusterin and subsequent lean tissue loss during weight management. Copyright © 2012 by the American College of Veterinary Internal Medicine.

Weight-loss strategies of South African female university students and comparison of weight management-related characteristics between dieters and non-dieters.

PubMed

Senekal, Marjanne; Lasker, Gabrielle L; van Velden, Lindsay; Laubscher, Ria; Temple, Norman J

2016-09-01

Female university students are at risk for weight gain and use of inappropriate weight-loss strategies. By gaining a greater understanding of the weight-loss strategies used by and weight management related characteristics of these students, effective weight management interventions for this vulnerable group can be developed. Two hundred and fifty female students from South Africa universities, aged 18-25 years, participated in this cross-sectional study; 162 attempted weight loss during the year preceding the study (dieters) and 88 were non-dieters. Weight and height were measured and BMI (kg/m(2)) computed. A self-administered questionnaire was used to record all other variables. Weight loss strategies were described for dieters and compared between BMI groups within the dieters group. Weight management related characteristics were compared between dieters and non-dieters. Statistical tests included Pearson Chi-square test, independent samples t-test or Mann-Whitney U test (depending on distribution of the data). Predictors for a higher BMI and being overweight/obese (BMI ≥25 kg/m(2)) were identified using regression models. Healthy weight-loss strategies included increased exercise and fruit/vegetable intake and decreased intake of sugar and fat containing items; unhealthy methods included eating little food and skipping meals; and extreme weight loss strategies included laxatives and vomiting. The most commonly used weight-loss product was Herbex. Dieters were characterized by a higher BMI, overestimation of their weight (especially normal weight students), dissatisfaction with weight and select body parts, higher intake of breakfast and healthy foods, lower intake of unhealthy foods, higher levels of vigorous physical activity, higher use of select informal weight-loss information sources and experiencing more pressure to lose weight from mothers, siblings and friends. Predictors of higher BMI and/or increased risk for BMI ≥25 included weight-loss attempt during the past year, race, dissatisfaction with waist, perception of currently being "chubby," and higher frequencies of intake of a snack and fatty foods. Attempting weight-loss is common among female students and predicts BMI. Healthy (mainly), unhealthy and extreme weight loss methods are used. Dieters are characterized by a less realistic body image, lower body satisfaction, higher pressure to lose weight, use of informal weight-management information and a healthier life-style.

The importance of body weight and weight management for military personnel.

PubMed

Naghii, Mohammad Reza

2006-06-01

Weight or fat reduction and maintenance among military personnel and attainment of desired body composition and physical appearance are considered important. A high level of body fat has been shown to have an adverse effect on performance in a number of military activities. The effect of rapid weight loss on performance appears to depend on the method of weight loss, the magnitude of weight loss, and the type of exercise or activity performance test used. Personnel who undertake imprudent weight-loss strategies, that is, personnel who try to change their usual body size by chronically restricting their food and fluid intake, may suffer a number of problems. Overweight personnel and their military coaches are just as susceptible to false ideas about weight loss and dieting as the rest of the community. Inappropriate weight loss causes a loss of lean tissue and can reduce, rather than enhance, performance. The understanding and promotion of safe, effective, appropriate weight-loss and weight-maintenance strategies represent important functions of the military system and officials. The greatest likelihood of success requires an integrated program, both during and after the weight-loss phase, in which assessment, increased energy expenditure through exercise and other daily activities, energy intake reduction, nutrition education, lifestyle changes, environmental changes, and psychological support are all components.

Weight loss, dysphagia and supplement intake in patients with amyotrophic lateral sclerosis (ALS): impact on quality of life and therapeutic options

PubMed Central

2013-01-01

Background Weight loss is a frequent feature in the motor neuron disease Amyotrophic lateral sclerosis (ALS). In this study we investigated possible causes of weight loss in ALS, its impact on mood/quality of life (QOL) and the benefit of high calorie nutritional/other dietary supplements and percutaneous endoscopic gastrostomy (PEG). Methods 121 ALS patients were interviewed and answered standardized questionnaires (Beck depression inventory - II, SF36 Health Survey questionnaire, revised ALS functional rating scale). Two years after the initial survey we performed a follow-up interview. Results In our ALS-cohort, 56.3% of the patients suffered from weight loss. Weight loss had a negative impact on QOL and was associated with a shorter survival. Patients who took high calorie nutritional supplements respectively had a PEG stated a great benefit regarding weight stabilization and/or QOL. 38.2% of our patients had significant weight loss without suffering from dysphagia. To clarify the reasons for weight loss in these patients, we compared them with patients without weight loss. The two groups did not differ regarding severity of disease, depression, frontotemporal dementia or fasciculations, but patients with weight loss declared more often increased respiratory work. Conclusions Weight loss is a serious issue in ALS and cannot always be attributed to dysphagia. Symptomatic treatment of weight loss (high calorie nutritional supplements and/ or PEG) should be offered more frequently. PMID:23848967

The defence of body weight: a physiological basis for weight regain after weight loss.

PubMed

Sumithran, Priya; Proietto, Joseph

2013-02-01

Although weight loss can usually be achieved by restricting food intake, the majority of dieters regain weight over the long-term. In the hypothalamus, hormonal signals from the gastrointestinal tract, adipose tissue and other peripheral sites are integrated to influence appetite and energy expenditure. Diet-induced weight loss is accompanied by several physiological changes which encourage weight regain, including alterations in energy expenditure, substrate metabolism and hormone pathways involved in appetite regulation, many of which persist beyond the initial weight loss period. Safe effective long-term strategies to overcome these physiological changes are needed to help facilitate maintenance of weight loss. The present review, which focuses on data from human studies, begins with an outline of body weight regulation to provide the context for the subsequent discussion of short- and long-term physiological changes which accompany diet-induced weight loss.

Weight-ing: the experience of waiting on weight loss.

PubMed

Glenn, Nicole M

2013-03-01

Perhaps we want to be perfect, strive for health, beauty, and the admiring gaze of others. Maybe we desire the body of our youth, the "healthy" body, the body that has just the right fit. Regardless of the motivation, we might find ourselves striving, wanting, and waiting on weight loss. What is it to wait on weight loss? I explore the meaning of this experience-as-lived using van Manen's guide to phenomenological reflection and writing. Weight has become an increasing focus of contemporary culture, demonstrated, for example, by a growing weight-loss industry and global obesity "epidemic." Weight has become synonymous with health status, and weight loss with "healthier." I examine the weight wait through experiences of the common and uncommon, considering relations to time, body, space, and the other with the aim of evoking a felt, embodied, emotive understanding of the meaning of waiting on weight loss. I also discuss the implications of the findings.

Weight loss in exclusively breastfed infants delivered by cesarean birth.

PubMed

Preer, Genevieve L; Newby, P K; Philipp, Barbara L

2012-05-01

Rates of exclusive breastfeeding during the postpartum hospital stay are a key measure of quality maternity care. Often, however, concern for excessive in-hospital weight loss leads to formula supplementation of breastfed infants. The American Academy of Pediatrics defines 7% weight loss as acceptable for breastfed newborns regardless of mode of delivery. Typical weight loss in exclusively breastfed infants delivered by cesarean birth has not been studied nor have possible correlates of greater weight loss in this population. To determine average weight loss in a cohort of exclusively breastfed infants delivered by cesarean birth and to identify correlates of greater than expected weight loss. We performed a retrospective chart review of exclusively breastfed infants delivered via cesarean birth at a Baby-Friendly hospital between 2005 and 2007. Average weight loss was calculated, and multivariate regression analysis was performed. Average weight loss during the hospital stay in our cohort of 200 infants was 7.2% ± 2.1% of birth weight, slightly greater than the American Academy of Pediatrics guideline of 7%. Absence of labor prior to delivery was significantly associated with a greater percentage of weight loss (P = .0004), as were lower gestational age (P = .0004) and higher birth weight (P < .0001). Maternal age, gravity, parity, infant sex, Apgar scores, and prior cesarean birth were not significantly associated. We conclude that for exclusively breastfed infants delivered by cesarean birth in a Baby-Friendly hospital, absence of labor prior to cesarean birth may be a previously unreported risk factor for greater than expected weight loss.

Weight maintenance, behaviors and barriers among previous participants of a university-based weight control program.

PubMed

Befort, C A; Stewart, E E; Smith, B K; Gibson, C A; Sullivan, D K; Donnelly, J E

2008-03-01

To examine weight loss maintenance among previous participants of a university-based behavioral weight management program and to compare behavioral strategies and perceived barriers between successful and unsuccessful maintainers. Previous program participants (n=179) completed mailed surveys assessing current weight, weight control behaviors and perceived barriers to weight loss maintenance. At 14.1+/-10.8 months following completion of treatment, survey respondents were on average 12.6+/-12.6 kg, or 11.3+/-10.7%, below baseline weight; 76.5% of respondents had successfully maintained weight, defined as maintaining a weight loss of at least 5% below baseline. Compared to unsuccessful maintainers, successful maintainers reported practicing four dietary and three physical activity weight control strategies more often and experiencing five barriers to healthy eating and exercise less often. After accounting for time since treatment and maximum weight loss while in treatment, the strongest correlates of successful weight loss maintenance were frequent exercise and perceived difficulty of weight management. Clinically meaningful weight loss maintenance was achieved by the majority of participants. Findings support the literature indicating that physical activity is one of the strongest predictors of successful weight loss maintenance. Findings also suggest that strategies to reduce the level of perceived effort required for long-term weight control may improve maintenance outcomes.

Windows(Registered Trademark)-Based Software Models Cyclic Oxidation Behavior

NASA Technical Reports Server (NTRS)

Smialek, J. L.; Auping, J. V.

2004-01-01

Oxidation of high-temperature aerospace materials is a universal issue for combustion-path components in turbine or rocket engines. In addition to the question of the consumption of material due to growth of protective scale at use temperatures, there is also the question of cyclic effects and spallation of scale on cooldown. The spallation results in the removal of part of the protective oxide in a discontinuous step and thereby opens the way for more rapid oxidation upon reheating. In experiments, cyclic oxidation behavior is most commonly characterized by measuring changes in weight during extended time intervals that include hundreds or thousands of heating and cooling cycles. Weight gains occurring during isothermal scale-growth processes have been well characterized as being parabolic or nearly parabolic functions of time because diffusion controls reaction rates. In contrast, the net weight change in cyclic oxidation is the sum of the effects of the growth and spallation of scale. Typically, the net weight gain in cyclic oxidation is determined only empirically (that is, by measurement), with no unique or straightforward mathematical connection to either the rate of growth or the amount of metal consumed. Thus, there is a need for mathematical modeling to infer spallation mechanisms. COSP is a computer program that models the growth and spallation processes of cyclic oxidation on the basis of a few elementary assumptions that were discussed in COSP: A Computer Model of Cyclic Oxidation, Oxidation of Metals, vol. 36, numbers 1 and 2, 1991, pages 81-112. Inputs to the model include the selection of an oxidation-growth law and a spalling geometry, plus oxide-phase, growth-rate, cycle-duration, and spall-constant parameters. (The spalling fraction is often shown to be a constant factor times the existing amount of scale.) The output of COSP includes the net change in weight, the amounts of retained and spalled oxide, the total amounts of oxygen and metal consumed, and the terminal rates of weight loss and metal consumption.

Behavioural factors related with successful weight loss 15 months post-enrolment in a commercial web-based weight-loss programme.

PubMed

Neve, Melinda J; Morgan, Philip J; Collins, Clare E

2012-07-01

As further understanding is required of what behavioural factors are associated with long-term weight-loss success, the aim of the present study was to determine the prevalence of successful weight loss 15 months post-enrolment in a commercial web-based weight-loss programme and which behavioural factors were associated with success. An online survey was completed 15 months post-enrolment in a commercial web-based weight-loss programme to assess weight-related behaviours and current weight. Participants were classified as successful if they had lost ≥5 % of their starting weight after 15 months. Commercial users of a web-based weight-loss programme. Participants enrolled in the commercial programme between August 2007 and May 2008. Six hundred and seventy-seven participants completed the survey. The median (interquartile range) weight change was -2·7 (-8·2, 1·6) % of enrolment weight, with 37 % achieving ≥5 % weight loss. Multivariate logistic regression analysis found success was associated with frequency of weight self-monitoring, higher dietary restraint score, lower emotional eating score, not skipping meals, not keeping snack foods in the house and eating takeaway foods less frequently. The findings suggest that individuals trying to achieve or maintain ≥5 % weight loss should be advised to regularly weigh themselves, avoid skipping meals or keeping snack foods in the house, limit the frequency of takeaway food consumption, manage emotional eating and strengthen dietary restraint. Strategies to assist individuals make these changes to behaviour should be incorporated within obesity treatments to improve the likelihood of successful weight loss in the long term.

A randomized study of dietary composition during weight-loss maintenance: Rationale, study design, intervention, and assessment

USDA-ARS?s Scientific Manuscript database

While many people with overweight or obesity can lose weight temporarily, most have difficulty maintaining weight loss over the long term. Studies of dietary composition typically focus on weight loss, rather than weight-loss maintenance, and rely on nutrition education and dietary counseling, rathe...

Popular Weight Loss Strategies: a Review of Four Weight Loss Techniques.

PubMed

Obert, Jonathan; Pearlman, Michelle; Obert, Lois; Chapin, Sarah

2017-11-09

The purpose of this paper is to review the epidemiology of obesity and the most recent literature on popular fad diets and exercise regimens that are used for weight loss. The weight loss plans that will be discussed in this article include juicing or detoxification diets, intermittent fasting, the paleo diet, and high intensity training. Despite the growing popularity of fad diets and exercise plans for weight loss, there are limited studies that actually suggest these particular regimens are beneficial and lead to long-term weight loss. Juicing or detoxification diets tend to work because they lead to extremely low caloric intake for short periods of time, however tend to lead to weight gain once a normal diet is resumed. Both intermittent fasting and the paleo diet lead to weight loss because of overall decreased caloric intake as well. Lastly, studies on short bursts of high intensity training have shown remarkable weight loss and improvements in cardiovascular health. Review of the literature does suggest that some fad diets and exercise plans do lead to weight loss; however, the studies are quite limited and are all based on the concept of caloric restriction.

Health risks, past usage, and intention to use weight loss products in normal weight women with high and low body dysphoria.

PubMed

Whisenhunt, B L; Williamson, D A; Netemeyer, R G; Andrews, C

2003-06-01

There are many health risks involved with the use of weight loss products by normal weight women. The mass media may compound this problem through the promotion of weight loss products and a thin body size. This study tested women's perceptions of different weight loss product ads to determine if body dysphoria (i.e., an over concern with body size and shape in normal weight people) was associated with risk beliefs, past behaviors, and intention toward using weight loss products. Normal weight women (age range = 18-41 yr), who were classified as either high (n=45) or low (n=43) on a measure of body dysphoria, rated different weight loss products according to their perception of health risks, past behavior, and their intention to consume the products. These products were a dietary fat substitute (olestra), a prescription obesity medication (sibutramine), and an over-the-counter appetite suppressant (phenylpropanolamine). High body dysphoric women reported higher intentions to use the products as well as increased prior use of two of the three weight loss products. High body dysphoric women did not believe that these weight loss products were harmless. They recognized potential health risks associated with using such products, but nonetheless, expressed intention to use these weight loss products at a higher frequency. Also, several variables related to body image were found to effectively discriminate normal weight women at risk for abusing weight loss products. This study found that women who do not need to lose weight but have significant body image concerns were willing to use potentially harmful weight loss products despite the knowledge that such products might pose significant health risks. Techniques utilized by advertising regulatory agencies such as warning labels did not have a strong deterrent effect for stated intentions to use the products. Implications of these findings for public health policy issues were discussed.

Mediators of weight loss and weight loss maintenance in middle-aged women.

PubMed

Teixeira, Pedro J; Silva, Marlene N; Coutinho, Sílvia R; Palmeira, António L; Mata, Jutta; Vieira, Paulo N; Carraça, Eliana V; Santos, Teresa C; Sardinha, Luís B

2010-04-01

Long-term behavioral self-regulation is the hallmark of successful weight control. We tested mediators of weight loss and weight loss maintenance in middle-aged women who participated in a randomized controlled 12-month weight management intervention. Overweight and obese women (N = 225, BMI = 31.3 +/- 4.1 kg/m(2)) were randomly assigned to a control or a 1-year group intervention designed to promote autonomous self-regulation of body weight. Key exercise, eating behavior, and body image variables were assessed before and after the program, and tested as mediators of weight loss (12 months, 86% retention) and weight loss maintenance (24 months, 81% retention). Multiple mediation was employed and an intention-to-treat analysis conducted. Treatment effects were observed for all putative mediators (Effect size: 0.32-0.79, P < 0.01 vs. controls). Weight change was -7.3 +/- 5.9% (12-month) and -5.5 +/- 5.0% (24-month) in the intervention group and -1.7 +/- 5.0% and -2.2 +/- 7.5% in controls. Change in most psychosocial variables was associated with 12-month weight change, but only flexible cognitive restraint (P < 0.01), disinhibition (P < 0.05), exercise self-efficacy (P < 0.001), exercise intrinsic motivation (P < 0.01), and body dissatisfaction (P < 0.05) predicted 24-month weight change. Lower emotional eating, increased flexible cognitive restraint, and fewer exercise barriers mediated 12-month weight loss (R(2) = 0.31, P < 0.001; effect ratio: 0.37), but only flexible restraint and exercise self-efficacy mediated 24-month weight loss (R(2) = 0.17, P < 0.001; effect ratio: 0.89). This is the first study to evaluate self-regulation mediators of weight loss and 2-year weight loss maintenance, in a large sample of overweight women. Results show that lowering emotional eating and adopting a flexible dietary restraint pattern are critical for sustained weight loss. For long-term success, interventions must also be effective in promoting exercise intrinsic motivation and self-efficacy.

Hypnotherapy in Weight Loss Treatment.

ERIC Educational Resources Information Center

Cochrane, Gordon; Friesen, John

1986-01-01

Investigated effects of hypnosis as a treatment for weight loss among women. The primary hypothesis that hypnosis is an effective treatment for weight loss was confirmed, but seven concomitant variables and the use of audiotapes were not significant contributors to weight loss. (Author/ABB)

Results of a faith-based weight loss intervention for black women.

PubMed

Fitzgibbon, Marian L; Stolley, Melinda R; Ganschow, Pamela; Schiffer, Linda; Wells, Anita; Simon, Nolanna; Dyer, Alan

2005-10-01

Obesity is a risk factor for a variety of chronic diseases. Although weight loss may reduce these risks, weight loss programs designed for black women have yielded mixed results. Studies suggest that religion/spirituality is a prominent component of black culture. Given this, the inclusion of religion/spirituality as an active component of a weight loss program may enhance the benefits of the program. The role of religion/spirituality, however, has not been specifically tested as a mechanism that enhances the weight loss process. This paper presents the results of "Faith on the Move," a randomized pilot study of a faith-based weight loss program for black women. The goals of the study were to estimate the effects of a 12-week culturally tailored, faith-based weight loss intervention on weight loss, dietary fat consumption and physical activity. The culturally tailored, faith-based weight loss intervention was compared to a culturally tailored weight loss intervention with no active faith component. Fifty-nine overweight/obese black women were randomized to one of the two interventions. Although the results were not statistically significant, the effect size suggests that the addition of the faith component improved results. These promising preliminary results will need to be tested in an adequately powered trial.

Gastric pouch emptying of solid food in patients with successful and unsuccessful weight loss after Roux-en-Y gastric bypass surgery.

PubMed

Deden, Laura N; Cooiman, Mellody I; Aarts, Edo O; Janssen, Ignace M C; Gotthardt, Martin; Hendrickx, Baudewijn W; Berends, Frits J

2017-11-01

After Roux-en-Y gastric bypass (RYGB), approximately 10% of patients have insufficient weight loss (excess body mass index loss<50%). Gastric pouch emptying may have a role in weight loss. To compare pouch emptying of patients with poor weight loss and patients with successful weight loss after RYGB. A research-intensive nonacademic hospital and center of expertise in bariatric surgery in the Netherlands METHODS: Female patients were included from among patients with the least (poor weight loss group [P-WL]) and the most weight loss (successful weight loss group [S-WL]) in our center 2 years after RYGB. Pouch emptying scintigraphy was performed after ingestion of a radiolabeled solid meal. Emptying curves, intestinal content (IC) at meal completion and after 15, 30, 45, and 60 minutes, half emptying time, and maximal pouch emptying rate were compared. Five individuals were included in P-WL and 5 in S-WL, on average 2.5 ± .3 years after RYGB. Total weight loss was 18 ± 4.1% in P-WL and 44 ± 5.7% in S-WL (P<.001). In P-WL, a fast initial pouch emptying and exponential emptying curve was observed, compared with a slower initial emptying and more linear curve in S-WL. Faster emptying in P-WL was also shown by a larger IC meal (42 ± 18% versus 4.0 ± 3.3%,), IC 15 (76 ± 15% versus 35 ± 22%), and IC 30 (85 ± 12% versus 54 ± 25%), and a greater maximal pouch emptying rate (17 ± 4.7 versus 5.6 ± 3.4%/min) compared with S-WL (P<.05). A linear correlation was found between total weight loss and maximal pouch emptying rate (Pearson R = .82, P = .004). Pouch emptying for solid food was faster in patients with the least weight loss compared with patients with the most weight loss after RYGB. If pouch emptying is an important mechanism in weight loss, altering the pouch outlet may improve poor weight loss management. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Hot corrosion behavior of magnesia-stabilized ceramic material in a lithium molten salt

NASA Astrophysics Data System (ADS)

Cho, Soo-Haeng; Kim, Sung-Wook; Kim, Dae-Young; Lee, Jong-Hyeon; Hur, Jin-Mok

2017-07-01

The isothermal and cyclic corrosion behaviors of magnesia-stabilized zirconia in a LiCl-Li2O molten salt were investigated at 650 °C in an argon atmosphere. The weights of as-received and corroded specimens were measured and the microstructures, morphologies, and chemical compositions were analyzed by scanning electron microscopy, X-ray energy dispersive spectroscopy, and X-ray diffraction. For processes where Li is formed at the cathode during electrolysis, the corrosion rate was about five times higher than those of isothermal and thermal cycling processes. During isothermal tests, the corrosion product Li2ZrO3 was formed after 216 h. During thermal cycling, Li2ZrO3 was not detected until after the completion of 14 cycles. There was no evidence of cracks, pores, or spallation on the corroded surfaces, except when Li was formed. We demonstrate that magnesia-stabilized zirconia is beneficial for increasing the hot corrosion resistance of structural materials subjected to high temperature molten salts containing Li2O.

High order finite volume WENO schemes for the Euler equations under gravitational fields

NASA Astrophysics Data System (ADS)

Li, Gang; Xing, Yulong

2016-07-01

Euler equations with gravitational source terms are used to model many astrophysical and atmospheric phenomena. This system admits hydrostatic balance where the flux produced by the pressure is exactly canceled by the gravitational source term, and two commonly seen equilibria are the isothermal and polytropic hydrostatic solutions. Exact preservation of these equilibria is desirable as many practical problems are small perturbations of such balance. High order finite difference weighted essentially non-oscillatory (WENO) schemes have been proposed in [22], but only for the isothermal equilibrium state. In this paper, we design high order well-balanced finite volume WENO schemes, which can preserve not only the isothermal equilibrium but also the polytropic hydrostatic balance state exactly, and maintain genuine high order accuracy for general solutions. The well-balanced property is obtained by novel source term reformulation and discretization, combined with well-balanced numerical fluxes. Extensive one- and two-dimensional simulations are performed to verify well-balanced property, high order accuracy, as well as good resolution for smooth and discontinuous solutions.

Early Weight Loss with Liraglutide 3.0 mg Predicts 1-Year Weight Loss and is Associated with Improvements in Clinical Markers.

PubMed

Fujioka, Ken; O'Neil, Patrick M; Davies, Melanie; Greenway, Frank; C W Lau, David; Claudius, Birgitte; Skjøth, Trine Vang; Bjørn Jensen, Christine; P H Wilding, John

2016-11-01

To identify an early response criterion for predicting ≥5% weight loss with liraglutide 3.0 mg at week 56 and to compare efficacy outcomes in early responders (ERs) and early nonresponders (ENRs). Using pooled data from the SCALE Obesity and Prediabetes and SCALE Diabetes trials, weight loss of ≥4% at 16 weeks best predicted ≥5% weight loss after 56 weeks. Weight loss and changes in cardiometabolic risk factors and health-related quality of life were evaluated in ERs (≥4% weight loss at week 16) and ENRs (<4% weight loss at week 16) completing 56 weeks' treatment. Proportions of ERs/ENRs to liraglutide 3.0 mg were 77.3%/22.7% (individuals without type 2 diabetes, T2D) and 62.7%/37.3% (those with T2D). Greater mean weight loss was observed in ERs versus ENRs: 10.8% versus 3.0% (without T2D) and 8.5% versus 3.1% (T2D). In both trials, greater proportions of ERs versus ENRs achieved ≥5%, >10%, and >15% weight loss at week 56 with liraglutide 3.0 mg. Greater improvements in cardiometabolic risk factors and health-related quality of life scores were observed in ERs versus ENRs. The early response criterion was clinically useful to identify individuals who would achieve clinically meaningful weight loss at 56 weeks. © 2016 The Authors Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS).

Early Weight Loss with Liraglutide 3.0 mg Predicts 1‐Year Weight Loss and is Associated with Improvements in Clinical Markers

PubMed Central

O'Neil, Patrick M.; Davies, Melanie; Greenway, Frank; C.W. Lau, David; Claudius, Birgitte; Skjøth, Trine Vang; Bjørn Jensen, Christine; P.H. Wilding, John

2016-01-01

Objective To identify an early response criterion for predicting ≥5% weight loss with liraglutide 3.0 mg at week 56 and to compare efficacy outcomes in early responders (ERs) and early nonresponders (ENRs). Methods Using pooled data from the SCALE Obesity and Prediabetes and SCALE Diabetes trials, weight loss of ≥4% at 16 weeks best predicted ≥5% weight loss after 56 weeks. Weight loss and changes in cardiometabolic risk factors and health‐related quality of life were evaluated in ERs (≥4% weight loss at week 16) and ENRs (<4% weight loss at week 16) completing 56 weeks’ treatment. Results Proportions of ERs/ENRs to liraglutide 3.0 mg were 77.3%/22.7% (individuals without type 2 diabetes, T2D) and 62.7%/37.3% (those with T2D). Greater mean weight loss was observed in ERs versus ENRs: 10.8% versus 3.0% (without T2D) and 8.5% versus 3.1% (T2D). In both trials, greater proportions of ERs versus ENRs achieved ≥5%, >10%, and >15% weight loss at week 56 with liraglutide 3.0 mg. Greater improvements in cardiometabolic risk factors and health‐related quality of life scores were observed in ERs versus ENRs. Conclusions The early response criterion was clinically useful to identify individuals who would achieve clinically meaningful weight loss at 56 weeks. PMID:27804269

Mediators of weight loss in a family-based intervention presented over the internet.

PubMed

White, Marney A; Martin, Pamela D; Newton, Robert L; Walden, Heather M; York-Crowe, Emily E; Gordon, Stewart T; Ryan, Donna H; Williamson, Donald A

2004-07-01

To assess the process variables involved in a weight loss program for African-American adolescent girls. Several process variables have been identified as affecting success in in vivo weight loss programs for adults and children, including program adherence, self-efficacy, and social support. The current study sought to broaden the understanding of these process variables as they pertain to an intervention program that is presented using the Internet. It was hypothesized that variables such as program adherence, dietary self-efficacy, psychological factors, and family environment factors would mediate the effect of the experimental condition on weight loss. Participants were 57 adolescent African-American girls who joined the program with one obese parent; family pairs were randomized to either a behavioral or control condition in an Internet-based weight loss program. Outcome data (weight loss) are reported for the first 6 months of the intervention. Results partially supported the hypotheses. For weight loss among adolescents, parent variables pertaining to life and family satisfaction were the strongest mediating variables. For parental weight loss, changes in dietary practices over the course of 6 months were the strongest mediators. The identification of factors that enhance or impede weight loss for adolescents is an important step in improving weight loss programs for this group. The current findings suggest that family/parental variables exert a strong influence on weight loss efforts for adolescents and should be considered in developing future programs. Copyright 2004 NAASO

Early weight loss predicts the reduction of obesity in men with erectile dysfunction and hypogonadism undergoing long-term testosterone replacement therapy.

PubMed

Salman, Mahmoud; Yassin, Dany-Jan; Shoukfeh, Huda; Nettleship, Joanne Elisabeth; Yassin, Aksam

2017-03-01

We and others have previously shown that testosterone replacement therapy (TRT) results in sustained weight loss in the majority of middle-aged hypogonadal men. Previously, however, a small proportion failed to lose at least 5% of their baseline weight. The reason for this is not yet understood. In the present study, we sought to identify early indicators that may predict successful long-term weight loss, defined as a reduction of at least 5% of total body weight relative to baseline weight (T0), in men with hypogonadism undergoing TRT. Eight parameters measured were assessed as potential predictors of sustained weight loss: loss of 3% or more of baseline weight after 1 year of TU treatment, severe hypogonadism, BMI, waist circumference, International Prostate Symptom Score (IPSS), glycated hemoglobin (HbA 1C ), age and use of vardenafil. Among the eight measured parameters, three factors were significantly associated with sustained weight loss over the entire period of TU treatment: (1) a loss of 3% of the baseline body weight after 1 year of TRT; (2) baseline BMI over 30; and (3) a waist circumference >102 cm. Age was not a predictor of weight loss.

Weight gain since menopause and its associations with weight loss maintenance in obese postmenopausal women

PubMed Central

Sénéchal, M; Arguin, H; Bouchard, DR; Carpentier, AC; Ardilouze, JL; Dionne, IJ; Brochu, M

2011-01-01

Objective To examine the association between weight gain since menopause and weight regain after a weight loss program. Methods Participants were 19 obese women who participated in a 15-week weight loss program and a 12-month follow-up. Main outcomes were: body composition, resting metabolic rate, energy intake, energy expenditure, and weight regain at follow-up. Results All body composition measures significantly decreased after intervention (all P ≤ 0.01) while all measures of fatness increased significantly after the 12-month follow-up (P ≤ 0.01). Body weight gain since menopause was associated with body weight regain (r = 0.65; P = 0.003) after follow-up even after adjustment for confounders. Conclusion Weight gain since menopause is associated with body weight regain following the weight loss program. Therefore, weight gain since menopause should be considered as a factor influencing weight loss maintenance in older women. PMID:21966216

Weight gain since menopause and its associations with weight loss maintenance in obese postmenopausal women.

PubMed

Sénéchal, M; Arguin, H; Bouchard, D R; Carpentier, A C; Ardilouze, J L; Dionne, I J; Brochu, M

2011-01-01

To examine the association between weight gain since menopause and weight regain after a weight loss program. Participants were 19 obese women who participated in a 15-week weight loss program and a 12-month follow-up. Main outcomes were: body composition, resting metabolic rate, energy intake, energy expenditure, and weight regain at follow-up. All body composition measures significantly decreased after intervention (all P ≤ 0.01) while all measures of fatness increased significantly after the 12-month follow-up (P ≤ 0.01). Body weight gain since menopause was associated with body weight regain (r = 0.65; P = 0.003) after follow-up even after adjustment for confounders. Weight gain since menopause is associated with body weight regain following the weight loss program. Therefore, weight gain since menopause should be considered as a factor influencing weight loss maintenance in older women.

Oxidation kinetics of some Ni-Cr alloys.

PubMed

Baran, G

1983-01-01

Oxidation kinetics of four Ni-Cr alloys and a high-purity nickel standard was determined under isothermal conditions in an air atmosphere. In addition, weight gains of the alloys were measured during a simulated pre-oxidation treatment. The alloys' behavior suggests that mechanisms of oxidation vary with temperature and alloy composition.

Concomitant changes in sleep duration and body weight and body composition during weight loss and 3-mo weight maintenance.

PubMed

Verhoef, Sanne P M; Camps, Stefan G J A; Gonnissen, Hanne K J; Westerterp, Klaas R; Westerterp-Plantenga, Margriet S

2013-07-01

An inverse relation between sleep duration and body mass index (BMI) has been shown. We assessed the relation between changes in sleep duration and changes in body weight and body composition during weight loss. A total of 98 healthy subjects (25 men), aged 20-50 y and with BMI (in kg/m(2)) from 28 to 35, followed a 2-mo very-low-energy diet that was followed by a 10-mo period of weight maintenance. Body weight, body composition (measured by using deuterium dilution and air-displacement plethysmography), eating behavior (measured by using a 3-factor eating questionnaire), physical activity (measured by using the validated Baecke's questionnaire), and sleep (estimated by using a questionnaire with the Epworth Sleepiness Scale) were assessed before and immediately after weight loss and 3- and 10-mo follow-ups. The average weight loss was 10% after 2 mo of dieting and 9% and 6% after 3- and 10-mo follow-ups, respectively. Daytime sleepiness and time to fall asleep decreased during weight loss. Short (≤7 h) and average (>7 to <9 h) sleepers increased their sleep duration, whereas sleep duration in long sleepers (≥9 h) did not change significantly during weight loss. This change in sleep duration was concomitantly negatively correlated with the change in BMI during weight loss and after the 3-mo follow-up and with the change in fat mass after the 3-mo follow-up. Sleep duration benefits from weight loss or vice versa. Successful weight loss, loss of body fat, and 3-mo weight maintenance in short and average sleepers are underscored by an increase in sleep duration or vice versa. This trial was registered at clinicaltrials.gov as NCT01015508.

Association of Weight Loss and Medication Adherence Among Adults With Type 2 Diabetes Mellitus: SHIELD (Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes)☆

PubMed Central

Grandy, Susan; Fox, Kathleen M.; Hardy, Elise

2013-01-01

Background Adherence to prescribed diabetes medications is suboptimal, which can lead to poor glycemic control and diabetic complications. Treatment-related weight gain is a side effect of some oral antidiabetic agents and insulin, which may negatively affect adherence to therapy. Objective This study investigated whether adults with type 2 diabetes mellitus (T2DM) who lost weight had better medication adherence than those who gained weight. Methods Weight change over 1 year (2007 to 2008) was assessed among respondents in the US Study to Help Improve Early evaluation and management of risk factors Leading to Diabetes (SHIELD). Weight loss of >1.0%, ≥3%, and ≥5% of weight was compared with weight gain of ≥1.0%. Medication adherence was assessed using the Morisky 4-item questionnaire for medication-taking behavior, with lower scores representing better adherence. Results There were 746 T2DM respondents who lost >1.0%, 483 who lost ≥3%, 310 who lost ≥5%, and 670 who gained ≥1.0% of weight. Each weight-loss group had significantly lower Morisky scores than the weight-gain group; mean scores of 0.389 versus 0.473 (P = 0.050) for the >1.0% weight-loss group, 0.365 versus 0.473 (P = 0.026) for the ≥3% weight-loss group, and 0.334 versus 0.473 (P = 0.014) for the ≥5% weight-loss group. Significantly fewer respondents who lost weight had received insulin, sulfonylurea, or thiazolidinedione therapy (57%) compared with respondents who gained weight (64%) (P = 0.002). Demographics, exercise habits, and dieting were similar between weight-loss and weight-gain groups. Conclusions T2DM respondents with weight loss had significantly better medication adherence and were less likely to be on treatment regimens that increase weight than T2DM respondents with weight gain. These findings suggest that strategies that lead to weight loss, including use of diabetes medications associated with weight loss, may improve medication adherence. PMID:24465048

A comparative flow visualization study of thermocapillary flow in drops in liquid-liquid systems

NASA Technical Reports Server (NTRS)

Balasubramaniam, R.; Rashidnia, N.

1991-01-01

Experiments are performed to visualize thermocapillary flow in drops in an immiscible host liquid. The host liquid used is silicone oil. Drops of three different liquids are used, viz, vegetable oil, water-methanol mixture anad pure methanol. Clear evidence of thermocapillary flow is seen in vegetable oil drops. For a mixture of water and methanol (approximately 50-50 by weight), natural convection is seen to dominate the flow outside the drop. Pure methanol drops exhibit thermocapillary flow, but dissolve in silicone oil. A small amount of water added to pure methanol significantly reduces the dissolution. Flow oscillations occur in this system for both isothermal and non-isothermal conditions.

Comparison of range of commercial or primary care led weight reduction programmes with minimal intervention control for weight loss in obesity: lighten Up randomised controlled trial.

PubMed

Jolly, Kate; Lewis, Amanda; Beach, Jane; Denley, John; Adab, Peymane; Deeks, Jonathan J; Daley, Amanda; Aveyard, Paul

2011-11-03

To assess the effectiveness of a range of weight management programmes in terms of weight loss. Eight arm randomised controlled trial. Primary care trust in Birmingham, England. 740 obese or overweight men and women with a comorbid disorder identified from general practice records. Weight loss programmes of 12 weeks' duration: Weight Watchers; Slimming World; Rosemary Conley; group based, dietetics led programme; general practice one to one counselling; pharmacy led one to one counselling; choice of any of the six programmes. The comparator group was provided with 12 vouchers enabling free entrance to a local leisure (fitness) centre. The primary outcome was weight loss at programme end (12 weeks). Secondary outcomes were weight loss at one year, self reported physical activity, and percentage weight loss at programme end and one year. Follow-up data were available for 658 (88.9%) participants at programme end and 522 (70.5%) at one year. All programmes achieved significant weight loss from baseline to programme end (range 1.37 kg (general practice) to 4.43 kg (Weight Watchers)), and all except general practice and pharmacy provision resulted in significant weight loss at one year. At one year, only the Weight Watchers group had significantly greater weight loss than did the comparator group (2.5 (95% confidence interval 0.8 to 4.2) kg greater loss,). The commercial programmes achieved significantly greater weight loss than did the primary care programmes at programme end (mean difference 2.3 (1.3 to 3.4) kg). The primary care programmes were the most costly to provide. Participants allocated to the choice arm did not have better outcomes than those randomly allocated to a programme. Commercially provided weight management services are more effective and cheaper than primary care based services led by specially trained staff, which are ineffective. Trial registration Current Controlled Trials ISRCTN25072883.

Determinants of Successful Weight Loss After Using a Commercial Web-Based Weight Reduction Program for Six Months: Cohort Study

PubMed Central

Postrach, Elisa; Aspalter, Rosa; Elbelt, Ulf; Koller, Michael; Longin, Rita; Schulzke, Jörg-Dieter

2013-01-01

Background The Internet is widely available and commonly used for health information; therefore, Web-based weight loss programs could provide support to large parts of the population in self-guided weight loss. Previous studies showed that Web-based weight loss interventions can be effective, depending on the quality of the program. The most effective program tools are visual progress charts or tools for the self-monitoring of weight, diet, and exercises. KiloCoach, a commercial program currently available in German-speaking countries, incorporates these features. A previous investigation showed that the program effectively supports users in losing weight. Objective We investigated weight loss dynamics stratified by weight loss success after 6-month use of KiloCoach. Furthermore, we analyzed possible associations between intensity of program use and weight loss. The results are intended for tailoring user recommendations for weight-loss Internet platforms. Methods Datasets of KiloCoach users (January 1, 2008 to December 31, 2011) who actively used the platform for 6 months or more were assigned to this retrospective analysis. Users (N=479) were 42.2% men, mean age of 44.0 years (SD 11.7), with a mean body mass index (BMI) of 31.7 kg/m2 (SD 3.2). Based on the weight loss achieved after 6 months, 3 success groups were generated. The unsuccessful group lost <5%, the moderate success group lost 5%-9.9%, and the high success group lost ≥10% of their baseline body weight. At baseline, the unsuccessful (n=261, 54.5%), moderate success (n=133, 27.8%), and high success (n=85, 17.8%) groups were similar in age, weight, BMI, and gender distribution. Results After 6 months, the unsuccessful group lost 1.2% (SD 2.4), the moderate success group lost 7.4% (SD 1.5), and the high success group lost 14.2% (SD 3.8) of their initial weight (P<.001). Multivariate regression showed that early weight loss (weeks 3-4), the total number of dietary protocols, and the total number of weight entries were independent predictors for 6-month weight reduction (all P<.001) explaining 52% of the variance in weight reduction. Sensitivity analysis by baseline carried forward method confirmed all independent predictors of 6-month weight loss and reduced the model fit by only 11%. The high success group lost weight faster and maintained weight loss more efficiently than the other groups (P<.001). Early weight loss was associated with weight maintenance after 1 year and 2 years (both P<.001). Weight dynamics did not differ between men and women over 6 months when adjusted for baseline and usage parameters (P=.91). The percentage of male long-term users was unusually high (42.2%). Conclusions Our results suggest that early weight loss and close program adherence (ie, 5 dietary protocols per week and weekly entering of current weight), especially in the early phase of program usage, can improve weight loss outcome. PMID:24126250

Macronutrient Content of the Diet: What Do We Know About Energy Balance and Weight Maintenance?

PubMed

Fleming, Jennifer A; Kris-Etherton, Penny M

2016-06-01

The 2013 AHA/ACC Clinical Guideline for the Management of Overweight and Obesity recommends a reduced energy diet for weight loss regardless of the macronutrient content. However, diet composition may affect the maintenance of weight loss. In general, a healthful dietary pattern with reduced portion sizes, low energy dense foods, and physical activity are successful for many. Certain populations, such as those with insulin resistance, may find reductions in carbohydrate and higher levels of unsaturated fats to be more effective and promote greater adherence. Of importance is that metabolic adaptations following weight loss also may impact weight loss maintenance and should be considered in the transition from weight loss to weight stabilization. Thus, weight loss and weight maintenance strategies are both important in an intervention for sustaining long-term behavior change.

Weight change following knee and hip joint arthroplasty-a six-month prospective study of adults with osteoarthritis.

PubMed

Teichtahl, Andrew J; Quirk, Emma; Harding, Paula; Holland, Anne E; Delany, Clare; Hinman, Rana S; Wluka, Anita E; Liew, Susan M; Cicuttini, Flavia M

2015-06-07

Inconsistent findings of weight change following total knee (TKA) and hip (THA) arthroplasty may largely be attributable to heterogeneous cohorts and varied definitions of weight loss. This study examined weight change following TKA and THA for osteoarthritis (OA). 64 participants with hip or knee OA were recruited from orthopaedic joint arthroplasty waiting lists at a single major Australian public hospital between March and October 2011. The Short Form (SF) 12 survey was used to assess baseline physical and mental functioning. 49 participants completed 6 month follow-up (20 from the THA group and 29 from the TKA group). The majority of subjects lost weight (>0 kg) 6 months following THA (70 %) and TKA (58.6 %). When at least a 5 % reduction in total body weight was used to define clinically significant weight loss, the proportion of people with weight loss was 37.9 % for TKA and 25 % for THA. Greater weight loss occurred 6 months following TKA compared with THA (7.2 % versus 3.7 % of body weight; p = 0.04). Worse pre-operative physical functioning (SF-12) was associated with greater weight loss following TKA (β = 0.22 kg, 95 % CI 0.02-0.42 kg; p = 0.04). Most people lost weight (>0 kg) 6 months following TKA and THA and a considerable proportion of people achieved ≥5 % loss of body weight. The magnitude of weight loss was greater following TKA than THA, with worse pre-operative function being a predictor of more weight loss. Further attention to weight management is required to assist a greater number of people to achieve a larger magnitude of weight loss following knee and hip joint arthroplasty.

Sex differences in the composition of weight gain and loss in overweight and obese adults.

PubMed

Millward, D Joe; Truby, Helen; Fox, Kenneth R; Livingstone, M Barbara E; Macdonald, Ian A; Tothill, Peter

2014-03-14

Sex differences in the ratio of fat mass (FM):fat-free mass (FFM) during weight change should differentially affect the extent of weight change during energy imbalance in men and women. In the present study, we determined FM and FFM contents by dual-energy X-ray absorptiometry and calculated the P-ratios (protein energy/total energy) of excess weight and weight loss during a randomised controlled trial of four commercial weight loss regimens. Overweight and obese women (n 210) and men (n 77) were studied at baseline and at 2 and 6 months during weight loss on four dietary regimens: Dr Atkins' New Diet Revolution; The Slim-Fast Plan; Weight-Watchers programme; Rosemary Conley's Diet and Fitness Plan. At baseline, the percentage of FFM (%FFM) and P-ratios of excess weight were 40 % and 0·071 for men and 27 % and 0·039 for women. At 2 months, men had lost twice as much weight as women and three times more FFM than women, indicating higher FFM content and P-ratios of weight loss for men, 0·052, than for women, 0·029, with no dietary effects. Between 2 and 6 months, the rate at which weight was lost decreased and the %FFM of weight loss decreased to similar low levels in men (7 %) and women (5 %): i.e. P-ratios of 0·009 and 0·006, respectively, with no dietary effects. Thus, for men compared with women, there were greater FFM content and P-ratios of weight change, which could partly, but not completely, explain their greater weight loss at 2 months. However, protein-conserving adaptations occur with increasing weight loss and over time, more extensively in men, eventually eliminating any sex difference in the composition of weight loss.

Dietary and psych predictors of weight loss after gastric bypass.

PubMed

Fox, Benjamin; Chen, Ellie; Suzo, Andrew; Jolles, Sally; Greenberg, Jacob A; Campos, Guilherme M; Voils, Corrine I; Funk, Luke M

2015-08-01

Identifying severely obese patients who will succeed after bariatric surgery remains challenging. Although numerous studies have attempted to identify preoperative patient characteristics associated with weight loss, the roles of many dietary and psychological characteristics are unclear. The purpose of this study was to examine preoperative dietary and psychological predictors of successful weight loss after bariatric surgery. This retrospective cohort study included all patients who underwent laparoscopic Roux-en-Y gastric bypass from September 2011-June 2013 at a single institution (n = 124). Patient demographics, comorbidities, dietary and psychological factors, and weight loss outcomes were extracted from the electronic medical record. Bivariate associations between these factors and successful weight loss (≥50% excess body weight) were examined. Factors significant at P ≤ 0.1 were included in a multivariate logistic regression model. On bivariate analysis, absence of either type 2 diabetes or hypertension, preoperative weight <270 lbs, no intentional past weight loss >50 lbs, no previous purging or family history of obesity, and no soda consumption preoperatively were associated with successful weight loss (P < 0.1). On multivariate analysis, successful weight loss was inversely associated with the presence of type 2 diabetes (odds ratio [OR], 0.22, 95% confidence interval [CI], 0.06-0.73), maximum intentional past weight loss >50 lbs (OR, 0.12 [95% CI, 0.04-0.43]), and decreasing soda consumption by >50% (OR, 0.27 [95% CI, 0.08-0.99]). Patients with type 2 diabetes mellitus, significant previous weight loss, and poor soda consumption habits are more likely to experience suboptimal weight loss after bariatric surgery. Additional preoperative counseling and close postoperative follow-up is warranted for these patients. Copyright © 2015 Elsevier Inc. All rights reserved.

Maintenance of weight loss or stability in subjects with obesity: a retrospective longitudinal analysis of a real-world population.

PubMed

DerSarkissian, Maral; Bhak, Rachel H; Huang, Joanna; Buchs, Sarah; Vekeman, Francis; Smolarz, B Gabriel; Brett, Jason; Ganguly, Rahul; Duh, Mei Sheng

2017-06-01

Characterize patterns of weight change among subjects with obesity. A retrospective observational longitudinal study of subjects with obesity was conducted using the General Electric Centricity electronic medical record database. Subjects who were ≥18 years old with BMI ≥30 kg/m 2 (first defining index BMI), had no medical conditions associated with unintentional weight loss, and had ≥4 BMI measurements/year for ≥2.5 years were included and categorized into groups (stable weight: within <5% of index BMI; modest weight loss: ≥5 to <10% of index BMI lost; moderate weight loss: ≥10 to <15% of index BMI lost; and high weight loss: ≥15% of index BMI lost) based on weight change during 6 months following index. No interventions were considered. Patterns of weight change were then assessed for 2 years. A total of 177,743 subjects were included: 85.1% of subjects were in the stable weight, 9.3% in the modest, 2.3% in the moderate, and 3.3% in the high weight loss groups. The proportion of subjects who maintained or continued to lose weight decreased over the 2 year observation period; 11% of those with high weight loss continued to lose weight and 19% maintained their weight loss. This group had the lowest percentage of subjects who regained ≥50% of lost weight and the lowest proportion of subjects with weight cycling (defined as not continuously losing, gaining, or maintaining weight throughout the 2 year observation period relative to its beginning). This trend persisted in subgroups with class II-III obesity, pre-diabetes, and type 2 diabetes. Weight cycling and regain were commonly observed. Subjects losing the most weight during the initial period were more likely to continue losing weight.

Predicting successful long-term weight loss from short-term weight-loss outcomes: new insights from a dynamic energy balance model (the POUNDS Lost study)123

PubMed Central

Ivanescu, Andrada E; Martin, Corby K; Heymsfield, Steven B; Marshall, Kaitlyn; Bodrato, Victoria E; Williamson, Donald A; Anton, Stephen D; Sacks, Frank M; Ryan, Donna; Bray, George A

2015-01-01

Background: Currently, early weight-loss predictions of long-term weight-loss success rely on fixed percent-weight-loss thresholds. Objective: The objective was to develop thresholds during the first 3 mo of intervention that include the influence of age, sex, baseline weight, percent weight loss, and deviations from expected weight to predict whether a participant is likely to lose 5% or more body weight by year 1. Design: Data consisting of month 1, 2, 3, and 12 treatment weights were obtained from the 2-y Preventing Obesity Using Novel Dietary Strategies (POUNDS Lost) intervention. Logistic regression models that included covariates of age, height, sex, baseline weight, target energy intake, percent weight loss, and deviation of actual weight from expected were developed for months 1, 2, and 3 that predicted the probability of losing <5% of body weight in 1 y. Receiver operating characteristic (ROC) curves, area under the curve (AUC), and thresholds were calculated for each model. The AUC statistic quantified the ROC curve’s capacity to classify participants likely to lose <5% of their body weight at the end of 1 y. The models yielding the highest AUC were retained as optimal. For comparison with current practice, ROC curves relying solely on percent weight loss were also calculated. Results: Optimal models for months 1, 2, and 3 yielded ROC curves with AUCs of 0.68 (95% CI: 0.63, 0.74), 0.75 (95% CI: 0.71, 0.81), and 0.79 (95% CI: 0.74, 0.84), respectively. Percent weight loss alone was not better at identifying true positives than random chance (AUC ≤0.50). Conclusions: The newly derived models provide a personalized prediction of long-term success from early weight-loss variables. The predictions improve on existing fixed percent-weight-loss thresholds. Future research is needed to explore model application for informing treatment approaches during early intervention. The POUNDS Lost study was registered at clinicaltrials.gov as NCT00072995. PMID:25733628

Information Processing Versus Social Cognitive Mediators of Weight Loss in a Podcast-Delivered Health Intervention

PubMed Central

Ko, Linda K.; Turner-McGrievy, Gabrielle; Campbell, Marci K.

2016-01-01

Podcasting is an emerging technology, and previous interventions have shown promising results using theory-based podcast for weight loss among overweight and obese individuals. This study investigated whether constructs of social cognitive theory and information processing theories (IPTs) mediate the effect of a podcast intervention on weight loss among overweight individuals. Data are from Pounds off Digitally, a study testing the efficacy of two weight loss podcast interventions (control podcast and theory-based podcast). Path models were constructed (n = 66). The IPTs—elaboration likelihood model, information control theory, and cognitive load theory—mediated the effect of a theory-based podcast on weight loss. The intervention was significantly associated with all IPTs. Information control theory and cognitive load theory were related to elaboration, and elaboration was associated with weight loss. Social cognitive theory constructs did not mediate weight loss. Future podcast interventions grounded in theory may be effective in promoting weight loss. PMID:24082027

The applicability of a weight loss grading system in cancer cachexia: a longitudinal analysis.

PubMed

Vagnildhaug, Ola Magne; Blum, David; Wilcock, Andrew; Fayers, Peter; Strasser, Florian; Baracos, Vickie E; Hjermstad, Marianne J; Kaasa, Stein; Laird, Barry; Solheim, Tora S

2017-10-01

A body mass index (BMI) adjusted weight loss grading system (WLGS) is related to survival in patients with cancer. The aim of this study was to examine the applicability of the WLGS by confirming its prognostic validity, evaluating its relationship to cachexia domains, and exploring its ability to predict cachexia progression. An international, prospective observational study of patients with incurable cancer was conducted. For each patient, weight loss grade was scored 0-4. Weight loss grade 0 represents a high BMI with limited weight loss, progressing through to weight loss grade 4 representing low BMI and a high degree of weight loss. Survival analyses were used to confirm prognostic validity. Analyses of variance were used to evaluate the relationship between the WLGS and cachexia domains [anorexia, dietary intake, Karnofsky performance status (KPS), and physical and emotional functioning]. Cox regression was used to evaluate if the addition of cachexia domains to the WLGS improved prognostic accuracy. Predictive ability of cachexia progression was assessed by estimating proportion of patients progressing to a more advanced weight loss grade. One thousand four hundred six patients were analysed (median age 66 years; 50% female, 63% KPS ≤ 70). The overall effect of the WLGS on survival was significant as expressed by change in -2 log likelihood (P < 0.001) and persisted after adjustment for age, sex, and cancer type and stage (P < 0.001). Median survival decreased across the weight loss grades ranging from 407 days (95% CI 312-502)-weight loss grade 0 to 119 days (95% CI 93-145)-weight loss grade 4. All cachexia domains significantly deteriorated with increasing weight loss grade, and deterioration was greatest for dietary intake, with a difference corresponding to 0.87 standard deviations between weight loss grades 0 and 4. The addition of KPS, anorexia, and physical and emotional functioning improved the prognostic accuracy of the WLGS. Likelihood of cachexia progression was greater in patients with weight loss grade 2 (39%) than that with weight loss grade 0 (19%) or 1 (22%). The WLGS is related to survival, cachexia domains, and the likelihood of progression. Adding certain cachexia domains to the WLGS improves prognostic accuracy. © 2017 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of the Society on Sarcopenia, Cachexia and Wasting Disorders.

Hunger, Food Cravings, and Diet Satisfaction are Related to Changes in Body Weight During a 6-Month Behavioral Weight Loss Intervention: The Beef WISE Study.

PubMed

Sayer, R Drew; Peters, John C; Pan, Zhaoxing; Wyatt, Holly R; Hill, James O

2018-05-31

Previously published findings from the Beef WISE Study (Beef's Role in Weight Improvement, Satisfaction, and Energy) indicated equivalent weight loss between two energy-restricted higher protein (HP) diets: A HP diet with ≥4 weekly servings of lean beef (B; n = 60) and a HP diet restricted in all red meats (NB; n = 60). Long-term adherence to dietary prescriptions is critical for weight management but may be adversely affected by changes in appetite, food cravings, and diet satisfaction that often accompany weight loss. A secondary a priori aim of the Beef WISE Study was to compare subjective ratings of appetite (hunger and fullness), food cravings, and diet satisfaction (compliance, satisfaction, and deprivation) between the diets and determine whether these factors influenced weight loss. Subjective appetite, food cravings, and diet satisfaction ratings were collected throughout the intervention, and body weight was measured at the baseline, after the weight loss intervention (week 16), and after an eight-week follow-up period (week 24). Hunger and cravings were reduced during weight loss compared to the baseline, while fullness was not different from the baseline. The reduction in cravings was greater for B vs. NB at week 16 only. Higher deprivation ratings during weight loss were reported in NB vs. B at weeks 16 and 24, but participants in both groups reported high levels of compliance and diet satisfaction with no difference between groups. Independent of group assignment, higher baseline hunger and cravings were associated with less weight loss, and greater diet compliance, diet satisfaction, and lower feelings of deprivation were associated with greater weight loss. Strategies to promote reduced feelings of hunger, cravings, and deprivation may increase adherence to dietary prescriptions and improve behavioral weight loss outcomes.

Does Successful Weight Loss in an Internet-Based Worksite Weight Loss Program Improve Employee Presenteeism and Absenteeism?

PubMed Central

Harden, Samantha M.; You, Wen; Almeida, Fabio A.; Hill, Jennie L.; Linnan, Laura A.; Allen, Kacie C.; Estabrooks, Paul A.

2017-01-01

Certain risk factors associated with overweight and obesity may lead to reduced productivity in the workforce (i.e., increased absenteeism and presenteeism). Participants in a large, Internet-based worksite weight loss intervention, who were present at follow-up (N = 1,030), completed a self-reported productivity measure (World Health Organization’s Health and Work Performance Questionnaire) at baseline and postintervention. Twenty-two percent of the participants lost a clinically meaningful amount of weight (≥5% weight loss). There were no statistically significant (p < .05) relationships between weight change from baseline to 12 months and change scores of absolute or relative absenteeism or for absolute or relative presenteeism. Within a modestly successful Internet-based, worksite weight loss intervention, weight loss did not improve self-reported absenteeism or presenteeism. Further studies are needed to explore the sensitivity of the World Health Organization’s Health and Work Performance Questionnaire and the long-term effects of weight loss on productivity. PMID:25842385

Does Successful Weight Loss in an Internet-Based Worksite Weight Loss Program Improve Employee Presenteeism and Absenteeism?

PubMed

Harden, Samantha M; You, Wen; Almeida, Fabio A; Hill, Jennie L; Linnan, Laura A; Allen, Kacie C; Estabrooks, Paul A

2015-12-01

Certain risk factors associated with overweight and obesity may lead to reduced productivity in the workforce (i.e., increased absenteeism and presenteeism). Participants in a large, Internet-based worksite weight loss intervention, who were present at follow-up (N = 1,030), completed a self-reported productivity measure (World Health Organization's Health and Work Performance Questionnaire) at baseline and postintervention. Twenty-two percent of the participants lost a clinically meaningful amount of weight (≥5% weight loss). There were no statistically significant (p < .05) relationships between weight change from baseline to 12 months and change scores of absolute or relative absenteeism or for absolute or relative presenteeism. Within a modestly successful Internet-based, worksite weight loss intervention, weight loss did not improve self-reported absenteeism or presenteeism. Further studies are needed to explore the sensitivity of the World Health Organization's Health and Work Performance Questionnaire and the long-term effects of weight loss on productivity. © 2015 Society for Public Health Education.

Cohort Study of the Success of Controlled Weight Loss Programs for Obese Dogs.

PubMed

German, A J; Titcomb, J M; Holden, S L; Queau, Y; Morris, P J; Biourge, V

2015-01-01

Most weight loss studies in obese dogs assess rate and percentage of weight loss in the first 2-3 months, rather than the likelihood of successfully reaching target weight. To determine outcome of controlled weight loss programs for obese dogs, and to determine the factors associated with successful completion. 143 obese dogs undergoing a controlled weight loss program. This was a cohort study of obese dogs attending a referral weight management clinic. Dogs were studied during their period of weight loss, and cases classified according to outcome as "completed" (reached target weight), "euthanized" (was euthanized before reaching target weight), or "stopped prematurely" (program stopped early for other reasons). Factors associated with successful completion were assessed using simple and multiple logistic regression. 87/143 dogs (61%) completed their weight loss program, 11 [8%] died or were euthanized, and the remaining 45 [32%] stopped prematurely. Reasons for dogs stopping prematurely included inability to contact owner, refusal to comply with weight management advice, or development of another illness. Successful weight loss was positively associated with a faster rate (P < .001), a longer duration (P < .001), and feeding a dried weight management diet (P = .010), but negatively associated with starting body fat (P < .001), and use of dirlotapide (P = .0046). Just over half of all obese dogs on a controlled weight loss program reach their target weight. Future studies should better clarify reasons for success in individual cases, and also the role of factors such as activity and behavioral modification. Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Changes in glucose-elicited blood metabolite responses following weight loss and long term weight maintenance in obese individuals with impaired glucose tolerance.

PubMed

Geidenstam, Nina; Danielsson, Anders P H; Spégel, Peter; Ridderstråle, Martin

2016-03-01

Weight loss improves insulin sensitivity and glucose tolerance in obese subjects with impaired glucose tolerance (IGT), but the long term dynamic effects on blood metabolites other than glucose during an oral glucose tolerance test (OGTT), are largely unknown. Here, we studied changes in OGTT-elicited metabolite patterns in obese subjects during a diet-induced weight loss study. Blood samples from 14 obese individuals with IGT were collected at 0, 30 and 120 min during a standard 75 g OGTT at baseline (BMI 44 ± 2 kg/m(2)), after weight loss (BMI 36 ± 2 kg/m(2)) and after weight maintenance (BMI 35 ± 2 kg/m(2)). Serum metabolite levels were analyzed by gas chromatography/mass spectrometry and compared to a lean glucose tolerant group. Changes in the OGTT-elicited metabolite patterns occurred differentially during weight loss and weight maintenance. Enhanced suppression of aromatic amino acids were associated with decreased insulinogenic index observed after weight loss (tyrosine: r=0.72, p=0.013; phenylalanine: r=0.63, p=0.039). The OGTT-elicited suppression and/or lack of increase in levels of glutamate, glutamine, isoleucine, leucine, and the fatty acids laurate, oleate and palmitate, improved towards the lean profile after weight maintenance, paralleling an improvement in glucose tolerance. The greater heterogeneity in the response before and after weight loss in the obese, compared to lean subjects, was markedly reduced after weight maintenance. Diet-induced weight loss followed by weight maintenance results in changes in metabolite profiles associated with either hepatic insulin sensitivity or peripheral glucose tolerance. Our results highlight the importance of evaluating the effects of weight loss and weight maintenance separately. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Weight loss medications in Canada – a new frontier or a repeat of past mistakes?

PubMed Central

Wharton, Sean; Lee, Jasmine; Christensen, Rebecca AG

2017-01-01

Current methods for the treatment of excess weight can involve healthy behavior changes, pharmacotherapy, and surgical interventions. Many individuals are able to lose some degree of weight through behavioral changes; however, they are often unable to maintain their weight loss long-term. This is in part due to physiological processes that cannot be addressed through behavioral changes alone. Bariatric surgery, which is the most successful treatment for excess weight to date, does result in physiological changes that can help with weight loss and weight maintenance. However, many patients either do not qualify or elect to not have this procedure. Fortunately, research has recently identified changes in neurochemicals (i.e., orexigens and anorexigens) that occur during weight loss and contribute to weight regain. The neurochemicals and hormones may be able to be targeted by medications to achieve greater and more sustained weight loss. Two medications are approved in adjunction to lifestyle management for weight loss in Canada: orlistat and liraglutide. Both medications are able to target physiological processes to help patients lose weight and maintain a greater amount of weight loss than with just behavioral modifications alone. Two other weight management medications, which also target specific physiological processes to aid in weight loss and its maintenance, a bupropion/naltrexone combination and lorcaserin, are currently pending approval in Canada. Nonetheless, there remain significant barriers for health care professionals to prescribe medications for weight loss, such as a lack of training and knowledge in the area of obesity. Until this has been addressed, and we begin treating obesity as we do other diseases, we are unlikely to combat the increasing trend of obesity in Canada and worldwide. PMID:29042804

Effects of canagliflozin on body weight and body composition in patients with type 2 diabetes over 104 weeks.

PubMed

Blonde, Lawrence; Stenlöf, Kaj; Fung, Albert; Xie, John; Canovatchel, William; Meininger, Gary

2016-05-01

Canagliflozin, a sodium glucose co-transporter 2 (SGLT2) inhibitor, has been associated with weight loss in a broad range of patients with type 2 diabetes mellitus (T2DM). This analysis further evaluated changes in body weight and composition with canagliflozin in two 104-week, Phase 3 studies. In Study 1, patients aged 18-80 years (N = 1,450) received canagliflozin 100 or 300 mg or glimepiride as add-on to metformin for a 52-week core treatment period, followed by a 52-week extension period. In Study 2, patients aged 55-80 years (N = 714) received canagliflozin 100 or 300 mg or placebo added to stable background antihyperglycemic agents for a 26-week core treatment period, followed by a 78-week extension period. Percent change from baseline in body weight; proportion of patients with any weight loss, ≥5% weight loss, and ≥10% weight loss; change in body mass index (BMI) and waist circumference; change in body weight across weight-loss quartiles; and changes in body composition were evaluated in both studies. Canagliflozin 100 and 300 mg provided sustained weight loss versus either glimepiride or placebo over 104 weeks. More patients experienced any weight loss and ≥5% weight loss with canagliflozin versus comparator. Across the 3 highest weight-loss quartiles, canagliflozin provided greater weight loss versus glimepiride or placebo. BMI and waist circumference reductions were observed with canagliflozin 100 and 300 mg versus either glimepiride or placebo over 104 weeks; more patients had BMI or waist circumference reductions with canagliflozin versus comparator. Body composition analysis indicated that the majority of weight loss was due to loss of fat mass. Canagliflozin was generally well tolerated, with increased incidence of adverse events related to the SGLT2 inhibition mechanism. Canagliflozin 100 and 300 mg provided sustained reductions in body weight, BMI, and waist circumference in a greater proportion of patients with T2DM versus glimepiride or placebo over 104 weeks. ClinicalTrials.gov NCT00968812, NCT01106651.

49 CFR 1005.7 - Weight as a measure of loss.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 8 2011-10-01 2011-10-01 false Weight as a measure of loss. 1005.7 Section 1005.7... VOLUNTARY DISPOSITION OF LOSS AND DAMAGE CLAIMS AND PROCESSING SALVAGE § 1005.7 Weight as a measure of loss. Where weight is used as a measure of loss in rail transit of scrap iron and steel and actual tare and...

49 CFR 1005.7 - Weight as a measure of loss.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 8 2010-10-01 2010-10-01 false Weight as a measure of loss. 1005.7 Section 1005.7... VOLUNTARY DISPOSITION OF LOSS AND DAMAGE CLAIMS AND PROCESSING SALVAGE § 1005.7 Weight as a measure of loss. Where weight is used as a measure of loss in rail transit of scrap iron and steel and actual tare and...

Weight loss practices among newly enrolling clients in a commercial weightloss program in Ghana.

PubMed

Ayisi-Addo, Sandra; Ayisi-Addo, Stephen; Ohemeng, Agartha

2016-03-01

In Ghana, obesity is showing a rising trend and there are weight loss initiatives being practised by individuals. However, the levels of commitment to such programs and the reasons for discontinuing have not been assessed. The objectives of this study were to investigate the weight loss practices of participants and reasons for quitting chosen weight loss programs. This was a cross-sectional study involving 50 subjects conveniently selected from people who were enrolling into a commercial weight loss program. A questionnaire was used to collect data on past weight loss practices and reasons for abandoning chosen programs. Data analysis was conducted using simple frequency and descriptive tests of the Excel software. More than half of the subjects (66%) had undertaken a weight loss practice before enrolment in study. Of these, 88.5% abandoned the strategy before the achievement of their desired weight goal. The three common programs that were practised were internet based diets (67.9%), commercial weight loss shakes (42.9%) and exercises (28.6%). Reasons given for abandoning programs included lack of sustainability (50%), lack of determination on the part of the client (15%), boredom with program (10%), not achieving desired results (10%), safety concerns (10%), and getting pregnant (5%). The findings suggest that future weight loss programs can be effective and have reduced attrition rates if they are designed to achieve sustainable dietary and other lifestyle changes, as well as boost motivation for weight loss.

Ineffectiveness of commercial weight-loss programs for achieving modest but meaningful weight loss: Systematic review and meta-analysis.

PubMed

McEvedy, Samantha M; Sullivan-Mort, Gillian; McLean, Siân A; Pascoe, Michaela C; Paxton, Susan J

2017-10-01

This study collates existing evidence regarding weight loss among overweight but otherwise healthy adults who use commercial weight-loss programs. Systematic search of 3 databases identified 11 randomized controlled trials and 14 observational studies of commercial meal-replacement, calorie-counting, or pre-packaged meal programs which met inclusion criteria. In meta-analysis using intention-to-treat data, 57 percent of individuals who commenced a commercial weight program lost less than 5 percent of their initial body weight. One in two (49%) studies reported attrition ≥30 percent. A second meta-analysis found that 37 percent of program completers lost less than 5 percent of initial body weight. We conclude that commercial weight-loss programs frequently fail to produce modest but clinically meaningful weight loss with high rates of attrition suggesting that many consumers find dietary changes required by these programs unsustainable.

Brief Self-Efficacy Scales for use in Weight-Loss Trials: Preliminary Evidence of Validity

PubMed Central

Wilson, Kathryn E.; Harden, Samantha M.; Almeida, Fabio A.; You, Wen; Hill, Jennie L.; Goessl, Cody; Estabrooks, Paul A.

2015-01-01

Self-efficacy is a commonly included cognitive variable in weight-loss trials, but there is little uniformity in its measurement. Weight-loss trials frequently focus on physical activity (PA) and eating behavior, as well as weight loss, but no survey is available that offers reliable measurement of self-efficacy as it relates to each of these targeted outcomes. The purpose of this study was to test the psychometric properties of brief, pragmatic self-efficacy scales specific to PA, healthful eating and weight-loss (4 items each). An adult sample (n=1790) from 28 worksites enrolled in a worksite weight-loss program completed the self-efficacy scale, as well as measures of PA, dietary fat intake, and weight, at baseline, 6-, and 12-months. The hypothesized factor structure was tested through confirmatory factor analysis, which supported the expected factor structure for three latent self-efficacy factors, specific to PA, healthful eating, and weight-loss. Measurement equivalence/invariance between relevant demographic groups, and over time was also supported. Parallel growth processes in self-efficacy factors and outcomes (PA, fat intake, and weight) support the predictive validity of score interpretations. Overall, this initial series of psychometric analyses supports the interpretation that scores on these scales reflect self-efficacy for PA, healthful eating, and weight-loss. The use of this instrument in large-scale weight-loss trials is encouraged. PMID:26619093

A systematic review of the interrelation between diet- and surgery-induced weight loss and vitamin D status.

PubMed

Himbert, Caroline; Ose, Jennifer; Delphan, Mahmoud; Ulrich, Cornelia M

2017-02-01

Obesity is a major global health problem and has been associated with vitamin D deficiency. Intentional weight loss may alter vitamin D status and, conversely, vitamin D supplementation has been hypothesized to aid in weight loss. A systematic literature search in PubMed/Medline identified 3173 articles of which 37 studies (randomized controlled trials (RCT) [n=17], non-RCTs [n=20]) are summarized as effect of: (I) diet-induced weight loss on vitamin D status (n=7), (II) vitamin D supplementation on diet-induced weight loss (n=11), (III) surgery-induced weight loss on vitamin D status (n=15), and (IV) vitamin D supplementation after surgery-induced weight loss on vitamin D status (n=5). While all studies on the effect of diet-induced weight loss on vitamin D status have consistently reported increased vitamin D levels, the targeted percentage of weight loss that is necessary for an increase has varied between 5% and >10%. N=11 RCTs testing the effect of vitamin D supplementation observe that vitamin D supplementation does not result in increased weight loss, but may affect body fat loss. Vitamin D deficiency and subsequent hyperparathyroidism have been detected in post-surgery patients, and there is evidence that vitamin D supplementation improves these post-surgery complications. We review the current evidence addressing the role of vitamin D status and supplementation in diet- and surgery-induced weight loss. Subsequently, we highlight gaps in current research and suggest directions for future research including differences in vitamin D supplementation dosages, indoor vs. outdoor exercise, and the assessment of vitamin D status in different body pools. Published by Elsevier Inc.

[Contraindications to weight reduction].

PubMed

Heini, A

2000-08-01

It is relatively well accepted that weight gain, even within the range of normal weight, is detrimental for health. The claimed long-term benefit of intentional weight loss is mainly based on a few observational trials, confounding intentional and non-intentional weight loss. The few data on obesity-related diseases prevented by intentional weight reduction have not been replicated. Thus, for lack of level-one evidence it is to date doubtful whether voluntary weight loss should be intensively recommended to obese individuals rather than other lifestyle-interventions, e.g. exercise training. The aim of this overview is to discuss some of the contraindications to intentional weight loss often ignored in recent debates. There is no intention to question the increased risk of overweight on morbidity and the need for preventing weight gain in our population. Besides well-known consequences secondary to rapid weight loss, e.g. gallstones and electrolyte disorders, some new aspects or more debated issues are discussed. Recent compelling data indicate a significant bone density loss after weight loss of a few kilograms. Knowledge on the impact of weight cycling mainly relies on cross-sectional data. So far there is no concluding evidence of adverse pathophysiological effects from weight cycling. Repeated dieting has been associated with eating disorders, although the cause-effect relationship has not been well established. At least on an empirical basis there seems to be a tolerance effect after repeated weight losing efforts. Pharmacotherapy tends more and more to be part of weight loss interventions. Although the currently available drugs are designed for long-term treatment, in practice they are rarely used longer than a few months, and therefore their use can be entirely questioned. Nonetheless, if employed properly for weight loss and weight maintenance, i.e. "for life", additional data on long-term effects on health are needed. Such risks can then be weighed against the risk of remaining obese. Even a limited detrimental effect on blood pressure, such as known for sibutramine, could compromise the beneficial effect of the drug on weight loss and maintenance. Further, the financial burden of weight loss is not to be underestimated. Besides diets and weight loss programs being a multi billion dollar business, the cost of patient care in cases of surgery for gallstones has, among other economic implications, to be considered. Finally, with the example of the recently investigated impact of fitness level on health, exercise training may be an alternative to weight loss. Whether obese or not, cardiovascular fitness is a strong, independent predictor of cardiovascular mortality and overall mortality. Most obese being unfit, a greater preventive impact might come from becoming more fit than from losing weight. This should only illustrate that there is still a long way to go until we have sufficient scientific data to be able to tell whether in the management of obesity weight loss or other interventions are of higher priority. In part, current recommendations to lose weight are biased by societal pressure, which overrules simple scientific evidence.

Perceptions of Strategies for Successful Weight Loss in Persons with Serious Mental Illness Participating in a Behavioral Weight Loss Intervention: A Qualitative Study

PubMed Central

Vazin, Roza; McGinty, Emma E.; Dickerson, Faith; Dalcin, Arlene; Goldsholl, Stacy; Enriquez, Meghan Oefinger; Jerome, Gerald J.; Gennusa, Joseph V.; Daumit, Gail L.

2016-01-01

Objective The purpose of this study was to describe perceptions of weight loss strategies, benefits, and barriers among persons with serious mental illness who lost weight in the ACHIEVE behavioral weight loss intervention. Methods Semi-structured interviews with 20 ACHIEVE participants were conducted and analyzed using an inductive coding approach. Results Participants perceived tailored exercise sessions, social support, and dietary strategies taught in ACHIEVE – such as reducing portion sizes and avoiding sugar-sweetened beverages – as useful weight loss strategies. Health benefits, improved physical appearance, self-efficacy, and enhanced ability to perform activities of daily living were commonly cited benefits of intervention participation and weight loss. Some participants reported challenges with giving up snack food and reducing portion sizes, and barriers to exercise related to medical conditions. Conclusions and Implications for Practice There is emerging evidence that behavioral weight loss interventions can lead to clinically meaningful reductions in body weight among persons with serious mental illness. The perspective of persons with serious mental illness regarding strategies for, benefits of, and barriers to weight loss during participation in behavioral weight loss programs provide insight into which elements of multicomponent interventions such as ACHIEVE are most effective. The results of this study suggest that tailored exercise programs, social support, and emphasis on non-clinical benefits of intervention participation, such as improvements in self-efficacy and the ability to participate more actively in family and community activities, are promising facilitators of engagement and success in behavioral weight loss interventions for the population with serious mental illness. PMID:27054900

Motivational interviewing fails to improve outcomes of a behavioral weight loss program for obese African American women: a pilot randomized trial.

PubMed

Befort, Christie A; Nollen, Nicole; Ellerbeck, Edward F; Sullivan, Debra K; Thomas, Janet L; Ahluwalia, Jasjit S

2008-10-01

Compared to other racial/ethnic groups, African American (AA) women are more likely to be obese but less likely to participate in weight loss interventions or to successfully lose weight. Sustained motivation for weight loss may be especially difficult for AA women due to socioeconomic and cultural factors. The purpose of this study was to examine whether the addition of motivational interviewing (MI) to a culturally-targeted behavioral weight loss program for AA women improved adherence to the program, diet and physical activity behaviors, and weight loss outcomes. Forty-four obese (mean BMI = 39.4, SD = 7.1) AA women were randomized to receive a 16-week behavioral weight loss program plus four MI sessions, or the same behavioral weight loss program plus four health education (HE; attention control) sessions. Results showed that participants in both MI and HE conditions lost a significant amount of weight, reduced their energy intake and percent calories from fat, and increased their fruit and vegetable consumption (ps < .05). However, adherence to the behavioral weight loss program and changes in diet, physical activity, and weight did not differ across MI and HE conditions. Future research is warranted to determine the subpopulations with which MI is most effective.

Effectiveness of weight loss interventions – is there a difference between men and women: a systematic review

PubMed Central

Williams, R L; Wood, L G; Collins, C E; Callister, R

2015-01-01

Effective strategies are required to reduce the prevalence of overweight and obesity; however, the effectiveness of current weight loss programmes is variable. One contributing factor may be the difference in weight loss success between men and women. A systematic review was conducted to determine whether the effectiveness of weight loss interventions differs between men and women. Randomized controlled trials published up until March 2014 were included. Effect sizes (Hedges' g) were used to examine the difference in weight outcomes between men and women. A total of 58 studies met the eligibility criteria with 49 studies of higher quality included in the final data synthesis. Eleven studies that directly compared weight loss in men and women reported a significant sex difference. Ten of these reported that men lost more weight than women; however, women also lost a significant amount of weight. Analysis of effect sizes found small differences in weight loss favouring men for both diet (g = 0.489) and diet plus exercise (g = 0.240) interventions. There is little evidence from this review to indicate that men and women should adopt different weight loss strategies. Current evidence supports moderate energy restriction in combination with exercise for weight loss in both men and women. PMID:25494712

Impact of sleep, screen time, depression and stress on weight change in the intensive weight loss phase of the LIFE study.

PubMed

Elder, C R; Gullion, C M; Funk, K L; Debar, L L; Lindberg, N M; Stevens, V J

2012-01-01

The LIFE study is a two-phase randomized clinical trial comparing two approaches to maintaining weight loss following guided weight loss. Phase I provided a nonrandomized intensive 6-month behavioral weight loss intervention to 472 obese (body mass index 30-50) adult participants. Phase II is the randomized weight loss maintenance portion of the study. This paper focuses on Phase I measures of sleep, screen time, depression and stress. The Phase I intervention consisted of 22 group sessions led over 26 weeks by behavioral counselors. Recommendations included reducing dietary intake by 500 calories per day, adopting the Dietary Approaches to Stop Hypertension (DASH) dietary pattern and increasing physical exercise to at least 180 min per week. Measures reported here are sleep time, insomnia, screen time, depression and stress at entry and post-weight loss intervention follow-up. The mean weight loss for all participants over the intensive Phase I weight loss intervention was 6.3 kg (s.d. 7.1). Sixty percent (N=285) of participants lost at least 4.5 kg (10 lbs) and were randomized into Phase II. Participants (N=472) attended a mean of 73.1% (s.d. 26.7) of sessions, completed 5.1 (s.d. 1.9) daily food records/week, and reported 195.1 min (s.d. 123.1) of exercise per week. Using logistic regression, sleep time (quadratic trend, P=0.030) and lower stress (P=0.024) at entry predicted success in the weight loss program, and lower stress predicted greater weight loss during Phase I (P=0.021). In addition, weight loss was significantly correlated with declines in stress (P=0.048) and depression (P=0.035). Results suggest that clinicians and investigators might consider targeting sleep, depression and stress as part of a behavioral weight loss intervention.

A descriptive study of past experiences with weight-loss treatment.

PubMed

Burke, Lora E; Steenkiste, Ann; Music, Edvin; Styn, Mindi A

2008-04-01

Overweight and obesity affect more than 60% of the adult population in the United States. Most adults who are overweight have a history of previous weight-loss treatment. Exploring individuals' past experiences with weight-loss treatment may allow improvements to the current approach to treatment. To examine individuals' prior experiences with weight-loss treatment, their treatment preferences, and what they found to be most and least satisfying. Cross-sectional descriptive study. Individuals (N=155) who had registered for a weight-loss study wait list and met standard criteria for a weight-loss program (aged 18 to 55 years and body mass index between 25 and 42). Questionnaire packets were mailed to participants. Descriptive analyses of the participants' past history with weight-loss treatment, treatment preference, self-efficacy, therapeutic efficacy, barriers to adherence to weight-loss treatment, barriers to healthy eating, and experiences associated with following a low-fat diet. One hundred ten participants (71%) returned completed questionnaire packets. The sample (82% white, 84% female, aged 42.6+/-8.5 years, and body mass index 33.5+/-5.3) was representative of those who seek weight-loss treatment in research settings. Participants were, on average, aged 21.1+/-8.9 years when they first tried a weight-loss program; 96.3% had tried to lose weight since that first time. The two most frequently tried programs were doing it on their own (93.5%) and commercial programs (70.8%). Barriers included having trouble controlling what I eat when hungry (71.3%), difficulty motivating myself to eat appropriately (66.2%), and using food as a reward (59.3%). Preferred weight-loss regimens were doing it on their own (30.6%) and a research program (22.4%). Participants were not seeking their preferred treatment. These data can be used to improve weight-loss programs by tailoring programs to meet the needs and preferences of participants.

300 K Isothermal Equations of State of DADNE, DNAN, and LX-17

NASA Astrophysics Data System (ADS)

Zaug, Joseph; Stavrou, Elissaios; Grivickas, Paulius; Pagoria, Phil; Hansen, Donald; Gagliardi, Franco; Sain, John; Bastea, Sorin

2017-06-01

Using a direct optical-based measurement approach, we report 10 GPa scale, 300 K isothermal equations of state (EOS) of single crystal 1,1-Diamino-2,2-dinitroethylene (DADNE, FOX-7), single crystal 2,4, Dintrosoanisole (DNAN) and a polymer blended explosive (PBX) composite LX-17 (92.5% triamino trinitro benzene (TATB), and 7.5% KEL-F 800). Results from quasi-statically compressed LX-17 represent the first-ever isothermal EOS measurements of a PBX. Recently, we published a paper outlining the utility of using in-house optical microscopy and interferometry (OMI) diagnostics to directly measure pressure dependent sample volumes of single crystals TATB and alpha-NTO compressed within diamond-anvil cell sample chambers. (Our TATB OMI results agree remarkably well with two independent powder x-ray diffraction EOS studies.) In addition, here we report single crystal pressure dependent indices of refraction from DADNE that clearly signal the onset of electronic and/or molecular (structural) transitions that are otherwise indistinguishable in 300 K plotted pressure-volume EOS isotherms. EOS model parameters are reported from weighted and unweighted fits to the OMI experimental data. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344.

Weight Loss and Complementary Health Practices: What the Science Says

MedlinePlus

... lifestyles, including weight-loss and weight management programs. Mindfulness Meditation To date there are only a few studies on the effects of mindfulness as a component of weight-loss programs, but ...

Weight Loss Surgery

MedlinePlus

... serious medical problems. Weight loss surgery (also called bariatric surgery) can help very obese people lose weight. But ... Gastric banding is the simplest of the three weight loss surgeries. People who get it might not lose as ...

The relationship of alcohol use to weight loss in the context of behavioral weight loss treatment

PubMed Central

Kase, Colleen A.; Piers, Amani D.; Schaumberg, Katherine; Forman, Evan M.; Butryn, Meghan L.

2016-01-01

Despite common wisdom that reducing alcohol intake will facilitate weight loss, little research has examined whether participants in behavioral weight loss treatments actually decrease their alcohol intake, or whether reduced alcohol intake relates to weight loss outcomes in this context. This study examined the relationship of alcohol use to energy intake excluding alcohol and to weight in 283 overweight and obese adults participating in a 26-session behavioral weight loss treatment. The majority of participants consumed low to moderate levels of alcohol at baseline. Participants who consumed alcohol at baseline meaningfully reduced their alcohol intake by end-of-treatment. Alcohol use did not relate to weight at baseline or end-of-treatment when controlling for relevant demographic variables, and change in alcohol use was unrelated to weight change in the overall sample during treatment. However, end-of-treatment alcohol intake did relate to end-of-treatment energy intake excluding alcohol. In addition, behavioral impulsivity and change in alcohol intake interacted to predict weight loss, such that decreases in alcohol intake were associated with greater percent weight loss at end-of-treatment for participants with higher levels of impulsivity. Alcohol consumption may lead to overeating episodes, and highly impulsive individuals may be at risk for increased energy intake during or after episodes of drinking. Therefore, the recommendation to reduce alcohol intake in the context of behavioral weight loss treatment seems warranted, particularly for individuals with high levels of impulsivity. PMID:26792773

The relationship of alcohol use to weight loss in the context of behavioral weight loss treatment.

PubMed

Kase, Colleen A; Piers, Amani D; Schaumberg, Katherine; Forman, Evan M; Butryn, Meghan L

2016-04-01

Despite common wisdom that reducing alcohol intake will facilitate weight loss, little research has examined whether participants in behavioral weight loss treatments actually decrease their alcohol intake, or whether reduced alcohol intake relates to weight loss outcomes in this context. This study examined the relationship of alcohol use to energy intake excluding alcohol and to weight in 283 overweight and obese adults participating in a 26-session behavioral weight loss treatment. The majority of participants consumed low to moderate levels of alcohol at baseline. Participants who consumed alcohol at baseline meaningfully reduced their alcohol intake by end-of-treatment. Alcohol use did not relate to weight at baseline or end-of-treatment when controlling for relevant demographic variables, and change in alcohol use was unrelated to weight change in the overall sample during treatment. However, end-of-treatment alcohol intake did relate to end-of-treatment energy intake excluding alcohol. In addition, behavioral impulsivity and change in alcohol intake interacted to predict weight loss, such that decreases in alcohol intake were associated with greater percent weight loss at end-of-treatment for participants with higher levels of impulsivity. Alcohol consumption may lead to overeating episodes, and highly impulsive individuals may be at risk for increased energy intake during or after episodes of drinking. Therefore, the recommendation to reduce alcohol intake in the context of behavioral weight loss treatment seems warranted, particularly for individuals with high levels of impulsivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Weight loss and retention in a commercial weight-loss program and the effect of corporate partnership.

PubMed

Martin, C K; Talamini, L; Johnson, A; Hymel, A M; Khavjou, O

2010-04-01

No studies report whether improvements to commercial weight-loss programs affect retention and weight loss. Similarly, no studies report whether enrolling in a program through work (with a corporate partner) affects retention and weight loss. To determine whether: (1) adding evidence-based improvements to a commercial weight-loss program increased retention and weight loss, (2) enrolling in a program through work increased retention and weight loss and (3) whether increased weight loss was because of longer retention. Data were collected on 60 164 adults who enrolled in Jenny Craig's Platinum Program over 1 year in 2001-2002. The program was subsequently renamed the Rewards Program and improved by increasing treatment personalization and including motivational interviewing. Data were then collected on 81 505 participants of the Rewards Program who enrolled during 2005 (2418 of these participants enrolled through their employer, but paid out-of-pocket). Retention (participants were considered active until >or=42 consecutive days were missed) and weight loss (percent of original body weight) from baseline to the last visit (data were evaluated through week 52) were determined. Alpha was set at 0.001. Mean (95% confidence interval (CI)) retention (weeks) was significantly higher among Rewards (19.5 (19.4-19.6)) compared with Platinum (16.3 (16.2-16.4)) participants, and Rewards Corporate (25.9 (25.0-26.8)) compared with Noncorporate (21.9 (21.7-22.1)) participants. Modified intent-to-treat analyses indicated that mean (95% CI) percent weight loss was significantly larger among Rewards (6.36 (6.32-6.40)) compared with Platinum (5.45 (5.41-5.49)) participants, and Rewards Corporate (7.16 (6.92-7.40)) compared with Noncorporate (6.20 (6.16-6.24)) participants, with and without adjustment for baseline participant characteristics. In all cases, greater weight loss was secondary to longer retention. The study was not a randomized controlled trial, rather, a translational effectiveness study. Improvements to a commercial program and enrolling through a corporate partner are associated with greater weight loss that is because of improved retention.

Insights From Google Play Store User Reviews for the Development of Weight Loss Apps: Mixed-Method Analysis

PubMed Central

Hartmann-Boyce, Jamie; Jebb, Susan; Albury, Charlotte; Nourse, Rebecca; Aveyard, Paul

2017-01-01

Background Significant weight loss takes several months to achieve, and behavioral support can enhance weight loss success. Weight loss apps could provide ongoing support and deliver innovative interventions, but to do so, developers must ensure user satisfaction. Objective The aim of this study was to conduct a review of Google Play Store apps to explore what users like and dislike about weight loss and weight-tracking apps and to examine qualitative feedback through analysis of user reviews. Methods The Google Play Store was searched and screened for weight loss apps using the search terms weight loss and weight track*, resulting in 179 mobile apps. A content analysis was conducted based on the Oxford Food and Activity Behaviors taxonomy. Correlational analyses were used to assess the association between complexity of mobile health (mHealth) apps and popularity indicators. The sample was then screened for popular apps that primarily focus on weight-tracking. For the resulting subset of 15 weight-tracking apps, 569 user reviews were sampled from the Google Play Store. Framework and thematic analysis of user reviews was conducted to assess which features users valued and how design influenced users’ responses. Results The complexity (number of components) of weight loss apps was significantly positively correlated with the rating (r=.25; P=.001), number of reviews (r=.28; P<.001), and number of downloads (r=.48; P<.001) of the app. In contrast, in the qualitative analysis of weight-tracking apps, users expressed preference for simplicity and ease of use. In addition, we found that positive reinforcement through detailed feedback fostered users’ motivation for further weight loss. Smooth functioning and reliable data storage emerged as critical prerequisites for long-term app usage. Conclusions Users of weight-tracking apps valued simplicity, whereas users of comprehensive weight loss apps appreciated availability of more features, indicating that complexity demands are specific to different target populations. The provision of feedback on progress can motivate users to continue their weight loss attempts. Users value seamless functioning and reliable data storage. PMID:29273575

Reductions in knee joint forces with weight loss are attenuated by gait adaptations in class III obesity.

PubMed

DeVita, Paul; Rider, Patrick; Hortobágyi, Tibor

2016-03-01

A consensus exists that high knee joint forces are a precursor to knee osteoarthritis and weight loss reduces these forces. Because large weight loss also leads to increased step length and walking velocity, knee contact forces may be reduced less than predicted by the magnitude of weight loss. The purpose was to determine the effects of weight loss on knee muscle and joint loads during walking in Class III obese adults. We determined through motion capture, force platform measures and biomechanical modeling the effects of weight loss produced by gastric bypass surgery over one year on knee muscle and joint loads during walking at a standard, controlled velocity and at self-selected walking velocities. Weight loss equaling 412 N or 34% of initial body weight reduced maximum knee compressive force by 824 N or 67% of initial body weight when walking at the controlled velocity. These changes represent a 2:1 reduction in knee force relative to weight loss when walking velocity is constrained to the baseline value. However, behavioral adaptations including increased stride length and walking velocity in the self-selected velocity condition attenuated this effect by ∼50% leading to a 392 N or 32% initial body weight reduction in compressive force in the knee joint. Thus, unconstrained walking elicited approximately 1:1 ratio of reduction in knee force relative to weight loss and is more indicative of walking behavior than the standard velocity condition. In conclusion, massive weight loss produces dramatic reductions in knee forces during walking but when patients stride out and walk faster, these favorable reductions become substantially attenuated. Copyright © 2016 Elsevier B.V. All rights reserved.

Does Spirituality Predict Weight Loss In A Behavioral Weight Loss Program?

DTIC Science & Technology

2009-01-01

SPIRITUALfl 1 A ~~D WEIGHT LOSS APPROVAL SHEET Title of Thesis: "Does Spirituality Predict Weight Loss in a Behavioral Weight Loss Program 7" Name...notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does...not display a currently valid OMB control number. 1. REPORT DATE 2009 2. REPORT TYPE 3. DATES COVERED 00-00-2009 to 00-00-2009 4. TITLE AND

Weight Loss Practices and Body Weight Perceptions among US College Students

ERIC Educational Resources Information Center

Wharton, Christopher M.; Adams, Troy; Hampl, Jeffrey S.

2008-01-01

Objective: The authors assessed associations between body weight perception and weight loss strategies. Participants: They randomly selected male and female college students (N = 38,204). Methods: The authors conducted a secondary data analysis of the rates of weight loss strategies and body weight perception among students who completed the…

Cluster analysis of the national weight control registry to identify distinct subgroups maintaining successful weight loss.

PubMed

Ogden, Lorraine G; Stroebele, Nanette; Wyatt, Holly R; Catenacci, Victoria A; Peters, John C; Stuht, Jennifer; Wing, Rena R; Hill, James O

2012-10-01

The National Weight Control Registry (NWCR) is the largest ongoing study of individuals successful at maintaining weight loss; the registry enrolls individuals maintaining a weight loss of at least 13.6 kg (30 lb) for a minimum of 1 year. The current report uses multivariate latent class cluster analysis to identify unique clusters of individuals within the NWCR that have distinct experiences, strategies, and attitudes with respect to weight loss and weight loss maintenance. The cluster analysis considers weight and health history, weight control behaviors and strategies, effort and satisfaction with maintaining weight, and psychological and demographic characteristics. The analysis includes 2,228 participants enrolled between 1998 and 2002. Cluster 1 (50.5%) represents a weight-stable, healthy, exercise conscious group who are very satisfied with their current weight. Cluster 2 (26.9%) has continuously struggled with weight since childhood; they rely on the greatest number of resources and strategies to lose and maintain weight, and report higher levels of stress and depression. Cluster 3 (12.7%) represents a group successful at weight reduction on the first attempt; they were least likely to be overweight as children, are maintaining the longest duration of weight loss, and report the least difficulty maintaining weight. Cluster 4 (9.9%) represents a group less likely to use exercise to control weight; they tend to be older, eat fewer meals, and report more health problems. Further exploration of the unique characteristics of these clusters could be useful for tailoring future weight loss and weight maintenance programs to the specific characteristics of an individual.

Psychological Changes following Weight Loss in Overweight and Obese Adults: A Prospective Cohort Study

PubMed Central

Jackson, Sarah E.; Steptoe, Andrew; Beeken, Rebecca J.; Kivimaki, Mika; Wardle, Jane

2014-01-01

Background Participation in weight loss programs is often associated with improved wellbeing alongside reduced cardio-metabolic risk. In contrast, population-based analyses have found no evidence of psychological benefits of weight loss, but this may be due to inclusion of healthy-weight individuals. We therefore examined cardio-metabolic and psychological changes following weight loss in a cohort of overweight/obese adults. Methods Data were from 1,979 overweight and obese adults (BMI ≥25 kg/m2; age ≥50 y), free of long-standing illness or clinical depression at baseline, from the English Longitudinal Study of Ageing. Participants were grouped according to four-year weight change into those losing ≥5% weight, those gaining ≥5%, and those whose weight was stable within 5%. Logistic regression examined changes in depressed mood (eight-item Center for Epidemiologic Studies Depression score ≥4), low wellbeing (Satisfaction With Life Scale score <20), hypertension (systolic blood pressure ≥140 mmHg or anti-hypertensives), and high triglycerides (≥1.7 mmol/l), controlling for demographic variables, weight loss intention, and baseline characteristics. Results The proportion of participants with depressed mood increased more in the weight loss than weight stable or weight gain groups (+289%, +86%, +62% respectively; odds ratio [OR] for weight loss vs. weight stable = 1.78 [95% CI 1.29–2.47]). The proportion with low wellbeing also increased more in the weight loss group (+31%, +22%, −4%), but the difference was not statistically significant (OR = 1.16 [0.81–1.66]). Hypertension and high triglyceride prevalence decreased in weight losers and increased in weight gainers (−28%, 4%, +18%; OR = 0.61 [0.45–0.83]; −47%, −13%, +5%; OR = 0.41 [0.28–0.60]). All effects persisted in analyses adjusting for illness and life stress during the weight loss period. Conclusions Weight loss over four years in initially healthy overweight/obese older adults was associated with reduction in cardio-metabolic risk but no psychological benefit, even when changes in health and life stresses were accounted for. These results highlight the need to investigate the emotional consequences of weight loss. PMID:25098417

Expectations for Weight Loss and Willingness to Accept Risk Among Patients Seeking Weight Loss Surgery

PubMed Central

Wee, Christina C.; Hamel, Mary Beth; Apovian, Caroline M.; Blackburn, George L.; Bolcic-Jankovic, Dragana; Colten, Mary Ellen; Hess, Donald T.; Huskey, Karen W.; Marcantonio, Edward R.; Schneider, Benjamin E.; Jones, Daniel B.

2015-01-01

Importance Weight loss surgery (WLS) has been shown to produce long-term weight loss but is not risk free or universally effective. The weight loss expectations and willingness to undergo perioperative risk among patients seeking WLS remain unknown. Objectives To examine the expectations and motivations of WLS patients and the mortality risks they are willing to undertake and to explore the demographic characteristics, clinical factors, and patient perceptions associated with high weight loss expectations and willingness to assume high surgical risk. Design We interviewed patients seeking WLS and conducted multivariable analyses to examine the characteristics associated with high weight loss expectations and the acceptance of mortality risks of 10% or higher. Setting Two WLS centers in Boston. Participants Six hundred fifty-four patients. Main Outcome Measures Disappointment with a sustained weight loss of 20% and willingness to accept a mortality risk of 10% or higher with WLS. Results On average, patients expected to lose as much as 38% of their weight after WLS and expressed disappointment if they did not lose at least 26%. Most patients (84.8%) accepted some risk of dying to undergo WLS, but only 57.5% were willing to undergo a hypothetical treatment that produced a 20% weight loss. The mean acceptable mortality risk to undergo WLS was 6.7%, but the median risk was only 0.1%; 19.5% of all patients were willing to accept a risk of at least 10%. Women were more likely than men to be disappointed with a 20% weight loss but were less likely to accept high mortality risk. After initial adjustment, white patients appeared more likely than African American patients to have high weight loss expectations and to be willing to accept high risk. Patients with lower quality-of-life scores and those who perceived needing to lose more than 10% and 20% of weight to achieve “any” health benefits were more likely to have unrealistic weight loss expectations. Low quality-of-life scores were also associated with willingness to accept high risk. Conclusions and Relevance Most patients seeking WLS have high weight loss expectations and believe they need to lose substantial weight to derive any health benefits. Educational efforts may be necessary to align expectations with clinical reality. PMID:23553327

Desire to Be Underweight: Exploratory Study on a Weight Loss App Community and User Perceptions of the Impact on Disordered Eating Behaviors

PubMed Central

Reddy, Madhu C; Booth, Kayla M; Kvasny, Lynette; Blair, Johnna L; Li, Victor; Poole, Erika S

2017-01-01

Background Mobile health (mHealth) apps for weight loss (weight loss apps) can be useful diet and exercise tools for individuals in need of losing weight. Most studies view weight loss app users as these types of individuals, but not all users have the same needs. In fact, users with disordered eating behaviors who desire to be underweight are also utilizing weight loss apps; however, few studies give a sense of the prevalence of these users in weight loss app communities and their perceptions of weight loss apps in relation to disordered eating behaviors. Objective The aim of this study was to provide an analysis of users’ body mass indices (BMIs) in a weight loss app community and examples of how users with underweight BMI goals perceive the impact of the app on disordered eating behaviors. Methods We focused on two aspects of a weight loss app (DropPounds): profile data and forum posts, and we moved from a broader picture of the community to a narrower focus on users’ perceptions. We analyzed profile data to better understand the goal BMIs of all users, highlighting the prevalence of users with underweight BMI goals. Then we explored how users with a desire to be underweight discussed the weight loss app’s impact on disordered eating behaviors. Results We found three main results: (1) no user (regardless of start BMI) starts with a weight gain goal, and most users want to lose weight; (2) 6.78% (1261/18,601) of the community want to be underweight, and most identify as female; (3) users with underweight BMI goals tend to view the app as positive, especially for reducing bingeing; however, some acknowledge its role in exacerbating disordered eating behaviors. Conclusions These findings are important for our understanding of the different types of users who utilize weight loss apps, the perceptions of weight loss apps related to disordered eating, and how weight loss apps may impact users with a desire to be underweight. Whereas these users had underweight goals, they often view the app as helpful in reducing disordered eating behaviors, which led to additional questions. Therefore, future research is needed. PMID:29025694

Resistance to exercise-induced weight loss: compensatory behavioral adaptations.

PubMed

Melanson, Edward L; Keadle, Sarah Kozey; Donnelly, Joseph E; Braun, Barry; King, Neil A

2013-08-01

In many interventions that are based on an exercise program intended to induce weight loss, the mean weight loss observed is modest and sometimes far less than what the individual expected. The individual responses are also widely variable, with some individuals losing a substantial amount of weight, others maintaining weight, and a few actually gaining weight. The media have focused on the subpopulation that loses little weight, contributing to a public perception that exercise has limited utility to cause weight loss. The purpose of the symposium was to present recent, novel data that help explain how compensatory behaviors contribute to a wide discrepancy in exercise-induced weight loss. The presentations provide evidence that some individuals adopt compensatory behaviors, that is, increased energy intake and/or reduced activity, that offset the exercise energy expenditure and limit weight loss. The challenge for both scientists and clinicians is to develop effective tools to identify which individuals are susceptible to such behaviors and to develop strategies to minimize their effect.

Resistance to exercise-induced weight loss: compensatory behavioral adaptations

PubMed Central

Melanson, Edward L.; Keadle, Sarah Kozey; Donnelly, Joseph E.; Braun, Barry; King, Neil A.

2013-01-01

In many interventions that are based on an exercise program intended to induce weight loss, the mean weight loss observed is modest and sometimes far less than the individual expected. The individual responses are also widely variable, with some individuals losing a substantial amount of weight, others maintaining weight, and a few actually gaining weight. The media have focused on the sub-population that loses little weight, contributing to a public perception that exercise has limited utility to cause weight loss. The purpose of the symposium was to present recent, novel data that help explain how compensatory behaviors contribute to a wide discrepancy in exercise-induced weight loss. The presentations provide evidence that some individuals adopt compensatory behaviors, i.e. increased energy intake and/or reduced activity, that offset the exercise energy expenditure and limit weight loss. The challenge for both scientists and clinicians is to develop effective tools to identify which individuals are susceptible to such behaviors, and to develop strategies to minimize their impact. PMID:23470300

Formulation/cure technology for ultrahigh molecular weight silphenylene-siloxane polymers

NASA Technical Reports Server (NTRS)

Hundley, N. H.; Patterson, W. J.

1985-01-01

Molecular weights above one million were achieved for methylvinylsilphenylene-siloxane terpolymers using a two-stage polymerization technique which was successfully scaled up to 200 grams. The resulting polymer was vulcanized by two different formulations and compared to an identically formulated commercial methylvinyl silicone on the basis of ultimate strength, Young's modulus, percent elongation at failure, and tear strength. Relative thermal/oxidative stabilities of the elastomers were assessed by gradient and isothermal thermogravimetric analyses performed in both air and nitrogen. The experimental elastomer exhibited enhanced thermal/oxidative stability and possed equivalent or superior mechanical properties. The effect of variations in prepolymer molecular weight on mechanical properties was also investigated.

The internal consistency of the standard gamble: tests after adjusting for prospect theory.

PubMed

Oliver, Adam

2003-07-01

This article reports a study that tests whether the internal consistency of the standard gamble can be improved upon by incorporating loss weighting and probability transformation parameters in the standard gamble valuation procedure. Five alternatives to the standard EU formulation are considered: (1) probability transformation within an EU framework; and, within a prospect theory framework, (2) loss weighting and full probability transformation, (3) no loss weighting and full probability transformation, (4) loss weighting and no probability transformation, and (5) loss weighting and partial probability transformation. Of the five alternatives, only the prospect theory formulation with loss weighting and no probability transformation offers an improvement in internal consistency over the standard EU valuation procedure.

Past and current weight change and forearm bone loss in middle-aged women: the Nord-Trøndelag Health Study, Norway.

PubMed

Forsmo, Siri; Langhammer, Arnulf; Schei, Berit

2009-01-01

The aim of this study was to investigate the association between bone loss and weight change before and concurrently to the assessment of forearm bone loss over 4.6 years in a population-based cohort of middle-aged women followed for more than 15 years. Among 8,856 women aged 45 to 60 years attending the first Nord-Trøndelag Health Study study, Norway (1984-1986), a 35% random sample was invited for forearm densitometry at Nord-Trøndelag Health Study 2 (1995-1997), and 2,188 women (78%) attended. After an average period of 4.6 years, they were subsequently invited for follow-up densitometry in 2001, and 1,421 women (67.8%) met. Weight and height were measured on all three occasions. During the total period of observation since baseline (15.5 y), the mean weight had increased by 3.4 kg, mostly in the youngest women. Weight loss had an accelerating and weight gain a decelerating effect on bone loss, and this was observed both for weight change occurring before the bone mineral density follow-up and for concurrent weight change. The relationship between prior weight gain or loss and bone loss seemed to persist, independent of the weight change observed during the period of bone loss assessment. Despite no mechanical impact of body weight on the forearm, weight loss in midlife women seems to be associated with a long-lasting negative effect on bone and vice versa for weight gain. This is presumably explained by humoral factors.

Favorable Changes in Serum Estrogens and Other Biological Factors After Weight Loss in Overweight or Obese Breast Cancer Survivors

PubMed Central

Rock, Cheryl L.; Pande, Chetna; Flatt, Shirley W.; Ying, Carl; Pakiz, Bilge; Parker, Barbara A.; Williams, Kathryn; Bardwell, Wayne A.; Heath, Dennis D.; Nichols, Jeanne F.

2014-01-01

Background Obesity is associated with increased risk for recurrence and all-cause mortality in breast cancer survivors. Excess adiposity is associated with increased estrogen, insulin, and leptin, and decreased sex hormone binding globulin (SHBG) concentrations, which may promote breast cancer progression and recurrence. This study aimed to assess the effects of weight loss on these factors. Patients and Methods Overweight or obese breast cancer survivors (N = 220) who were enrolled in a weight loss intervention study provided baseline and follow-up blood samples and weight data. Serum estrogens, SHBG, insulin, and leptin were measured at baseline, 6 and 18 months. Results Weight loss of ≥5% of initial weight decreased leptin and insulin compared with those who did not achieve that amount of weight loss (P < .0001). Weight loss also increased SHBG at 6 and 18 months (P < .01). Postmenopausal women who lost ≥5% of body weight at 6 months had lower estrone (P = .02), estradiol (P = .002), and bioavailable estradiol (P = .001) concentrations than women who did not lose at least 5% of body weight, and weight loss at 18 months was significantly related to change in serum bioavailable estradiol concentration (P = 0.02). Conclusion Favorable changes in estrogens, SHBG, insulin, and leptin were observed in association with weight loss in these overweight or obese women who had been diagnosed and treated for breast cancer. Weight loss appears to have favorable effects on hormonal and biological factors associated with increased risk for recurrence and poorer prognosis. PMID:23375717

Contributions of Weight Perceptions to Weight Loss Attempts: Differences by Body Mass Index and Gender

PubMed Central

Lemon, Stephenie C.; Rosal, Milagros C.; Zapka, Jane; Borg, Amy; Andersen, Victoria

2009-01-01

Previous studies have consistently observed that women are more likely to perceive themselves as overweight compared to men. Similarly, women are more likely than men to report trying to lose weight. Less is known about the impact that self-perceived weight has on weight loss behaviors of adults and whether this association differs by gender. We conducted a cross-sectional analysis among an employee sample to determine the association of self-perceived weight on evidence-based weight loss behaviors across genders, accounting for body mass index (BMI) and demographic characteristics. Women were more likely than men to consider themselves to be overweight across each BMI category, and were more likely to report attempting to lose weight. However, perceiving oneself to be overweight was a strong correlate for weight loss attempts across both genders. The effect of targeting accuracy of self-perceived weight status in weight loss interventions deserves research attention. PMID:19188102

Relationship of cravings with weight loss and hunger: results from a 6 month worksite weight loss intervention

USDA-ARS?s Scientific Manuscript database

We examined the association of food cravings with weight loss and eating behaviors in a 6 month worksite lifestyle weight loss program. This randomized controlled trial of the intervention versus a wait-listed control was conducted at 4 worksites, and 95 participants completed outcome assessments ...

48 CFR 252.237-7015 - Loss or damage (weight of articles).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Loss or damage (weight of... of Provisions And Clauses 252.237-7015 Loss or damage (weight of articles). As prescribed in 237.7101(d), use the following clause: Loss or Damage (Weight of Articles) (DEC 1991) (a) The Contractor...

48 CFR 252.237-7015 - Loss or damage (weight of articles).

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Loss or damage (weight of... of Provisions And Clauses 252.237-7015 Loss or damage (weight of articles). As prescribed in 237.7101(d), use the following clause: Loss or Damage (Weight of Articles) (DEC 1991) (a) The Contractor...

Biological Mechanisms that Promote Weight Regain Following Weight Loss in Obese Humans

PubMed Central

Ochner, Christopher N.; Barrios, Dulce M.; Lee, Clement D.; Pi-Sunyer, F. Xavier

2013-01-01

Weight loss dieting remains the treatment of choice for the vast majority of obese individuals, despite the limited long-term success of behavioral weight loss interventions. The reasons for the near universal unsustainability of behavioral weight loss in [formerly] obese individuals have not been fully elucidated, relegating researchers to making educated guesses about how to improve obesity treatment, as opposed to developing interventions targeting the causes of weight regain. This article discusses research on several factors that may contribute to weight regain following weight loss achieved through behavioral interventions, including adipose cellularity, endocrine function, energy metabolism, neural responsivity, and addiction-like neural mechanisms. All of these mechanisms are engaged prior to weight loss, suggesting that so called “anti-starvation” mechanisms are activated via reductions in energy intake, rather than depletion of energy stores. Evidence suggests that these mechanisms are not necessarily part of a homeostatic feedback system designed to regulate body weight or even anti-starvation mechanisms per se. Though they may have evolved to prevent starvation, they appear to be more accurately described as anti-weight loss mechanisms, engaged with caloric restriction irrespective of the adequacy of energy stores. It is hypothesized that these factors may combine to create a biological disposition that fosters the maintenance of an elevated body weight and work to restore the highest sustained body weight, thus precluding the long-term success of behavioral weight loss. It may be necessary to develop interventions that attenuate these biological mechanisms in order to achieve long-term weight reduction in obese individuals. PMID:23911805

Perceived Self-Efficacy and Financial Incentives: Factors Affecting Health Behaviors and Weight Loss in a Workplace Weight Loss Intervention.

PubMed

Faghri, Pouran D; Simon, Julia; Huedo-Medina, Tania; Gorin, Amy

2017-05-01

To evaluate if self-efficacy (SE) and financial incentives (FI) mediate the effect of health behavior on weight loss in a group of overweight and obese nursing-home employees participating in a 16-week weight-loss intervention with 12-week follow-up. Ninety nine overweight/obese (body mass index [BMI] > 25) employees from four nursing-homes participated, with a mean age of 46.98 years and BMI of 35.33. Nursing-homes were randomized to receiving an incentive-based intervention (n = 51) and no incentive (n = 48). Participants' health behaviors and eating and exercise self-efficacy (Ex-SE) were assessed at week 1, 16, and 28 using a self-reported questionnaire. Mediation and moderated mediation analysis assessed relationships among these variables. Eating self-efficacy (Eat-SE) and Ex-SE were significant mediators between health behaviors and weight loss (P < 0.05). Incentives significantly moderated the effects of self-efficacy (P = 0.00) on weight loss. Self-efficacy and FI may affect weight loss and play a role in weight-loss interventions.

The relationship of social support with treatment adherence and weight loss in Latinos with type 2 diabetes.

PubMed

Marquez, Becky; Anderson, Andrea; Wing, Rena R; West, Delia S; Newton, Robert L; Meacham, Maria; Hazuda, Helen P; Peters, Anne; Montez, Maria G; Broyles, Stephanie T; Walker, Martha; Evans-Hudsnall, Gina

2016-03-01

Little is known about the effects of social support on weight loss in Latinos. This study determined whether sex moderated and treatment adherence mediated the association between social support and weight loss. Data from 278 Latino males and females with type 2 diabetes in the Intensive Lifestyle Intervention of the Look AHEAD trial were analyzed. Multivariable modeling tested for moderation and parallel multiple mediator modeling simultaneously tested the mediating effects of adherence to physical activity, diet, and session attendance on the relationship between baseline social support and percent weight loss at 1 year. Social support for physical activity (having family and friends join in physical activity) was related to weight loss. Adherence to physical activity was related to both social support for physical activity and weight loss. Sex did not moderate these relationships. Adherence to physical activity completely mediated the relationship between social support for physical activity and weight loss. Increasing companionship for physical activity may be an effective intervention strategy to promote behaviors important for weight loss among Latinos. © 2016 The Obesity Society.

The relationship of social support with treatment adherence and weight loss in Latinos with type 2 diabetes

PubMed Central

Marquez, Becky; Anderson, Andrea; Wing, Rena R.; West, Delia S.; Newton, Robert L.; Meacham, Maria; Hazuda, Helen P.; Peters, Anne; Montez, Maria G.; Broyles, Stephanie T.; Walker, Martha; Evans-Hudsnall, Gina

2016-01-01

Objective Little is known about the effects of social support on weight loss in Latinos. This study determined whether sex moderated and treatment adherence mediated the association between social support and weight loss. Methods Data from 278 Latino males and females with type 2 diabetes in the Intensive Lifestyle Intervention of the Look AHEAD trial were analyzed. Multivariable modeling tested for moderation and parallel multiple mediator modeling simultaneously tested the mediating effects of adherence to physical activity, diet, and session attendance on the relationship between baseline social support and percent weight loss at 1 year. Results Social support for physical activity (having family and friends join in physical activity) was related to weight loss. Adherence to physical activity was related to both social support for physical activity and weight loss. Sex did not moderate these relationships. Adherence to physical activity completely mediated the relationship between social support for physical activity and weight loss. Conclusion Increasing companionship for physical activity may be an effective intervention strategy to promote behaviors important for weight loss among Latinos. PMID:26833676

Weight regain is related to decreases in physical activity during weight loss.

PubMed

Wang, Xuewen; Lyles, Mary F; You, Tongjian; Berry, Michael J; Rejeski, W Jack; Nicklas, Barbara J

2008-10-01

To examine whether adaptations in physical activity energy expenditure (PAEE) and resting metabolic rate (RMR) during weight loss were associated with future weight regain in overweight/obese, older women. Thirty-four overweight/obese (BMI = 25-40 kg x m(-2)), postmenopausal women underwent a 20-wk weight loss intervention of hypocaloric diet with (low- or high-intensity) or without treadmill walking (weekly caloric deficit was approximately 11,760 kJ), with a subsequent 12-month follow-up. RMR (via indirect calorimetry), PAEE (by RT3 accelerometer), and body composition (by dual-energy x-ray absorptiometry) were measured before and after intervention. Body weight and self-reported information on physical activity were collected after intervention and at 6 and 12 months after intervention. The intervention resulted in decreases in body weight, lean mass, fat mass, percent body fat, RMR, and PAEE (P < 0.001 for all). Weight regain was 2.9 +/- 3.3 kg (-3.1 to +9.2 kg) at 6 months and 5.2 +/- 5.0 kg (-2.3 to +21.7 kg) at 12 months after intervention. The amount of weight regained after 6 and 12 months was inversely associated with decreases in PAEE during the weight loss intervention (r = -0.521, P = 0.002 and r = -0.404, P = 0.018, respectively), such that women with larger declines in PAEE during weight loss experienced greater weight regain during follow-up. Weight regain was not associated with changes in RMR during intervention or with self-reported physical activity during follow-up. This study demonstrates that although both RMR and PAEE decreased during weight loss in postmenopausal women, maintaining high levels of daily physical activity during weight loss may be important to mitigate weight regain after weight loss.

Weight loss efficacy of a novel mobile Diabetes Prevention Program delivery platform with human coaching

PubMed Central

Michaelides, Andreas; Raby, Christine; Wood, Meghan; Farr, Kit

2016-01-01

Objective To evaluate the weight loss efficacy of a novel mobile platform delivering the Diabetes Prevention Program. Research Design and Methods 43 overweight or obese adult participants with a diagnosis of prediabetes signed-up to receive a 24-week virtual Diabetes Prevention Program with human coaching, through a mobile platform. Weight loss and engagement were the main outcomes, evaluated by repeated measures analysis of variance, backward regression, and mediation regression. Results Weight loss at 16 and 24 weeks was significant, with 56% of starters and 64% of completers losing over 5% body weight. Mean weight loss at 24 weeks was 6.58% in starters and 7.5% in completers. Participants were highly engaged, with 84% of the sample completing 9 lessons or more. In-app actions related to self-monitoring significantly predicted weight loss. Conclusions Our findings support the effectiveness of a uniquely mobile prediabetes intervention, producing weight loss comparable to studies with high engagement, with potential for scalable population health management. PMID:27651911

Web-based weight loss in primary care: a randomized controlled trial.

PubMed

Bennett, Gary G; Herring, Sharon J; Puleo, Elaine; Stein, Evelyn K; Emmons, Karen M; Gillman, Matthew W

2010-02-01

Evidence is lacking regarding effective and sustainable weight loss approaches for use in the primary care setting. We conducted a 12-week randomized controlled trial to evaluate the short-term efficacy of a web-based weight loss intervention among 101 primary care patients with obesity and hypertension. Patients had access to a comprehensive website that used a moderate-intensity weight loss approach designed specifically for web-based implementation. Patients also participated in four (two in-person and two telephonic) counseling sessions with a health coach. Intent-to-treat analysis showed greater weight loss at 3 months (-2.56 kg; 95% CI -3.60, -1.53) among intervention participants (-2.28 +/- 3.21 kg), relative to usual care (0.28 +/- 1.87 kg). Similar findings were observed among intervention completers (-3.05 kg; 95% CI -4.24, -1.85). High rates of participant retention (84%) and website utilization were observed, with the greatest weight loss found among those with a high frequency of website logins (quartile 4 vs. 1: -4.16 kg; 95% CI -1.47, -6.84). The intervention's approach promoted moderate weight loss at 12 weeks, though greater weight loss was observed among those with higher levels of website utilization. Efficacious web-based weight loss interventions can be successfully offered in the primary care setting.

Expert Coaching in Weight Loss: Retrospective Analysis

PubMed Central

Kushner, Robert F; Hill, James O; Lindquist, Richard; Brunning, Scott; Margulies, Amy

2018-01-01

Background Providing coaches as part of a weight management program is a common practice to increase participant engagement and weight loss success. Understanding coach and participant interactions and how these interactions impact weight loss success needs to be further explored for coaching best practices. Objective The purpose of this study was to analyze the coach and participant interaction in a 6-month weight loss intervention administered by Retrofit, a personalized weight management and Web-based disease prevention solution. The study specifically examined the association between different methods of coach-participant interaction and weight loss and tried to understand the level of coaching impact on weight loss outcome. Methods A retrospective analysis was performed using 1432 participants enrolled from 2011 to 2016 in the Retrofit weight loss program. Participants were males and females aged 18 years or older with a baseline body mass index of ≥25 kg/m², who also provided at least one weight measurement beyond baseline. First, a detailed analysis of different coach-participant interaction was performed using both intent-to-treat and completer populations. Next, a multiple regression analysis was performed using all measures associated with coach-participant interactions involving expert coaching sessions, live weekly expert-led Web-based classes, and electronic messaging and feedback. Finally, 3 significant predictors (P<.001) were analyzed in depth to reveal the impact on weight loss outcome. Results Participants in the Retrofit weight loss program lost a mean 5.14% (SE 0.14) of their baseline weight, with 44% (SE 0.01) of participants losing at least 5% of their baseline weight. Multiple regression model (R2=.158, P<.001) identified the following top 3 measures as significant predictors of weight loss at 6 months: expert coaching session attendance (P<.001), live weekly Web-based class attendance (P<.001), and food log feedback days per week (P<.001). Attending 80% of expert coaching sessions, attending 60% of live weekly Web-based classes, and receiving a minimum of 1 food log feedback day per week were associated with clinically significant weight loss. Conclusions Participant’s one-on-one expert coaching session attendance, live weekly expert-led interactive Web-based class attendance, and the number of food log feedback days per week from expert coach were significant predictors of weight loss in a 6-month intervention. PMID:29535082

Fat-free mass loss generated with weight loss in overweight and obese adults: What may we expect?

PubMed

Dixon, J B; Lambert, E A; Grima, M; Rice, T; Lambert, G W; Straznicky, N E

2015-01-01

There is concern that intentional weight loss may generate excessive loss of fat-free mass (FFM). Idealists target minimal loss of FFM, while others consider that FFM loss of up to 25% of weight loss is acceptable. In a cross-sectional study of 275 weight-stable, overweight or obese adults, we used whole-body dual-energy X-ray absorptiometry to measure FFM. A range of models was used to estimate the expected ΔFFM/Δweight ratio required to attain the body composition of a weight-stable individual at a lower body mass index (BMI). Higher BMI was associated linearly with higher FFM in men and women. Proportional ΔFFM/Δweight was influenced by sex, BMI and age. Direct scatter plot analysis, quadratic curve fit modelling and linear FFM-BMI modelling provided similar estimates for each model of ΔFFM/Δweight ratio, with 40% for men and 33% for women. These results show that the 25% rule is inappropriate and our estimates are higher than those generally reported after intentional weight loss indicating favourable preservation of FFM. © 2014 John Wiley & Sons Ltd.

Predictors of initial weight loss among women with abdominal obesity: a path model using self-efficacy and health-promoting behaviour.

PubMed

Choo, Jina; Kang, Hyuncheol

2015-05-01

To identify predictors of initial weight loss among women with abdominal obesity by using a path model. Successful weight loss in the initial stages of long-term weight management may promote weight loss maintenance. A longitudinal study design. Study participants were 75 women with abdominal obesity, who were enrolled in a 12-month Community-based Heart and Weight Management Trial and followed until a 6-month assessment. The Weight Efficacy Lifestyle, Exercise Self-Efficacy and Health Promoting Lifestyle Profile-II measured diet self-efficacy, exercise self-efficacy and health-promoting behaviour respectively. All endogenous and exogenous variables used in our path model were change variables from baseline to 6 months. Data were collected between May 2011-May 2012. Based on the path model, increases in both diet and exercise self-efficacy had significant effects on increases in health-promoting behaviour. Increases in diet self-efficacy had a significant indirect effect on initial weight loss via increases in health-promoting behaviour. Increases in health-promoting behaviour had a significant effect on initial weight loss. Among women with abdominal obesity, increased diet self-efficacy and health-promoting behaviour were predictors of initial weight loss. A mechanism by which increased diet self-efficacy predicts initial weight loss may be partially attributable to health-promoting behavioural change. However, more work is still needed to verify causality. Based on the current findings, intensive nursing strategies for increasing self-efficacy for weight control and health-promoting behaviour may be essential components for better weight loss in the initial stage of a weight management intervention. © 2015 John Wiley & Sons Ltd.

Valuing the benefits of weight loss programs: an application of the discrete choice experiment.

PubMed

Roux, Larissa; Ubach, Christina; Donaldson, Cam; Ryan, Mandy

2004-08-01

Obesity is a leading health threat. Determination of optimal therapies for long-term weight loss remains a challenge. Evidence suggests that successful weight loss depends on the compliance of weight loss program participants with their weight loss efforts. Despite this, little is known regarding the attributes influencing such compliance. The purpose of this study was to assess, using a discrete choice experiment (DCE), the relative importance of weight loss program attributes to its participants and to express these preferences in terms of their willingness to pay for them. A DCE survey explored the following weight loss program attributes in a sample of 165 overweight adults enrolled in community weight loss programs: cost, travel time required to attend, extent of physician involvement (e.g., none, monthly, every 2 weeks), components (e.g., diet, exercise, behavior change) emphasized, and focus (e.g., group, individual). The rate at which participants were willing to trade among attributes and the willingness to pay for different configurations of combined attributes were estimated using regression modeling. All attributes investigated appeared to be statistically significant. The most important unit change was "program components emphasized" (e.g., moving from diet only to diet and exercise). The majority of participants were willing to pay for weight loss programs that reflected their preferences. The DCE tool was useful in quantifying and understanding individual preferences in obesity management and provided information that could help to maximize the efficiency of existing weight loss programs or the design of new programs.

Using data mining to predict success in a weight loss trial.

PubMed

Batterham, M; Tapsell, L; Charlton, K; O'Shea, J; Thorne, R

2017-08-01

Traditional methods for predicting weight loss success use regression approaches, which make the assumption that the relationships between the independent and dependent (or logit of the dependent) variable are linear. The aim of the present study was to investigate the relationship between common demographic and early weight loss variables to predict weight loss success at 12 months without making this assumption. Data mining methods (decision trees, generalised additive models and multivariate adaptive regression splines), in addition to logistic regression, were employed to predict: (i) weight loss success (defined as ≥5%) at the end of a 12-month dietary intervention using demographic variables [body mass index (BMI), sex and age]; percentage weight loss at 1 month; and (iii) the difference between actual and predicted weight loss using an energy balance model. The methods were compared by assessing model parsimony and the area under the curve (AUC). The decision tree provided the most clinically useful model and had a good accuracy (AUC 0.720 95% confidence interval = 0.600-0.840). Percentage weight loss at 1 month (≥0.75%) was the strongest predictor for successful weight loss. Within those individuals losing ≥0.75%, individuals with a BMI (≥27 kg m -2 ) were more likely to be successful than those with a BMI between 25 and 27 kg m -2 . Data mining methods can provide a more accurate way of assessing relationships when conventional assumptions are not met. In the present study, a decision tree provided the most parsimonious model. Given that early weight loss cannot be predicted before randomisation, incorporating this information into a post randomisation trial design may give better weight loss results. © 2017 The British Dietetic Association Ltd.

Preserving Healthy Muscle during Weight Loss123

PubMed Central

Cava, Edda; Yeat, Nai Chien; Mittendorfer, Bettina

2017-01-01

Weight loss is the cornerstone of therapy for people with obesity because it can ameliorate or completely resolve the metabolic risk factors for diabetes, coronary artery disease, and obesity-associated cancers. The potential health benefits of diet-induced weight loss are thought to be compromised by the weight-loss–associated loss of lean body mass, which could increase the risk of sarcopenia (low muscle mass and impaired muscle function). The objective of this review is to provide an overview of what is known about weight-loss–induced muscle loss and its implications for overall physical function (e.g., ability to lift items, walk, and climb stairs). The currently available data in the literature show the following: 1) compared with persons with normal weight, those with obesity have more muscle mass but poor muscle quality; 2) diet-induced weight loss reduces muscle mass without adversely affecting muscle strength; 3) weight loss improves global physical function, most likely because of reduced fat mass; 4) high protein intake helps preserve lean body and muscle mass during weight loss but does not improve muscle strength and could have adverse effects on metabolic function; 5) both endurance- and resistance-type exercise help preserve muscle mass during weight loss, and resistance-type exercise also improves muscle strength. We therefore conclude that weight-loss therapy, including a hypocaloric diet with adequate (but not excessive) protein intake and increased physical activity (particularly resistance-type exercise), should be promoted to maintain muscle mass and improve muscle strength and physical function in persons with obesity. PMID:28507015

Obesity: Risk factors, complications, and strategies for sustainable long-term weight management.

PubMed

Fruh, Sharon M

2017-10-01

The aims of this article are to review the effects of obesity on health and well-being and the evidence indicating they can be ameliorated by weight loss, and consider weight-management strategies that may help patients achieve and maintain weight loss. Narrative review based on literature searches of PubMed up to May 2016 with no date limits imposed. Search included terms such as "obesity," "overweight," "weight loss," "comorbidity," "diabetes," cardiovascular," "cancer," "depression," "management," and "intervention." Over one third of U.S. adults have obesity. Obesity is associated with a range of comorbidities, including diabetes, cardiovascular disease, obstructive sleep apnea, and cancer; however, modest weight loss in the 5%-10% range, and above, can significantly improve health-related outcomes. Many individuals struggle to maintain weight loss, although strategies such as realistic goal-setting and increased consultation frequency can greatly improve the success of weight-management programs. Nurse practitioners have key roles in establishing weight-loss targets, providing motivation and support, and implementing weight-loss programs. With their in-depth understanding of the research in the field of obesity and weight management, nurse practitioners are well placed to effect meaningful changes in weight-management strategies deployed in clinical practice. ©2017 American Association of Nurse Practitioners.

The impact of physician weight discussion on weight loss in US adults.

PubMed

Pool, Andrew C; Kraschnewski, Jennifer L; Cover, Lindsay A; Lehman, Erik B; Stuckey, Heather L; Hwang, Kevin O; Pollak, Kathryn I; Sciamanna, Christopher N

2014-01-01

The increasing prevalence of overweight and obesity in the United States and worldwide is at epidemic levels. Physicians may play a vital role in addressing this epidemic. We aimed to examine the association of a physician's discussion of patients’ weight status with self-reported weight loss. We hypothesized that physician discussion of patients’ being overweight is associated with increased weight loss in patients with overweight and obesity. Data analysis of participants (n = 5054) in the National Health and Nutritional Examination Survey (NHANES) in 2005-2008. The main outcome was rates of self-reported weight loss and the association with physicians’ discussion of their patients’ weight status. Overweight and obese participants were significantly more likely to report a 5% weight loss in the past year if their doctor had told them they were overweight (adjusted OR (AOR) 1.88; 95% CI 1.45-2.44; AOR 1.79; 95% CI 1.30-2.46, respectively). Physicians’ direct discussion of their patients’ weight status is associated with clinically significant patient weight loss and may be a targetable intervention. Further studies are needed to determine if increasing physician discussion of patients’ weight status leads to significant weight loss. © 2014 Asian Oceanian Association for the Study of Obesity . Published by Elsevier Ltd. All rights reserved.

A pilot study of the effects of behavioral weight loss treatment on fibromyalgia symptoms.

PubMed

Shapiro, Jennifer R; Anderson, Drew A; Danoff-Burg, Sharon

2005-11-01

Previous studies have found a relation between weight loss and pain severity in various chronic pain populations. However, there has been little research examining the relation between body mass index (BMI) and fibromyalgia syndrome (FMS). The purpose of this pilot study was to investigate the relationship between BMI and FMS symptoms and to determine if FMS symptoms would decrease following weight loss. Overweight and obese women participated in a 20-week behavioral weight loss treatment. Participants, on average, lost 9.2 lbs (4.4% of their initial weight), and there were significant pre-postimprovements on several outcome measures. Although weight was not significantly related to pain at baseline, weight loss significantly predicted a reduction in FMS, pain interference, body satisfaction, and quality of life (QOL). Findings suggest that behavioral weight loss treatment could be included in the treatment for overweight/obese women with FMS.

Quality of Life after Diet or Exercise-Induced Weight Loss in Overweight to Obese Postmenopausal Women: The SHAPE-2 Randomised Controlled Trial.

PubMed

van Gemert, Willemijn A M; van der Palen, Job; Monninkhof, Evelyn M; Rozeboom, Anouk; Peters, Roelof; Wittink, Harriet; Schuit, Albertine J; Peeters, Petra H

2015-01-01

This study investigates the effect of a modest weight loss either by a calorie restricted diet or mainly by increased physical exercise on health related quality of life (HRQoL) in overweight-to-obese and inactive postmenopausal women. We hypothesize that HRQoL improves with weight loss, and that exercise-induced weight loss is more effective for this than diet-induced weight loss. The SHAPE-2 trial was primarily designed to evaluate any additional effect of weight loss by exercise compared with a comparable amount of weight loss by diet on biomarkers relevant for breast cancer risk. In the present analysis we focus on HRQoL. We randomly assigned 243 eligible women to a diet (n = 97), exercise (n = 98), or control group (n = 48). Both interventions aimed for 5-6 kg weight loss. HRQoL was measured at baseline and after 16 weeks by the SF-36 questionnaire. Data of 214 women were available for analysis. Weight loss was 4.9 kg (6.1%) and 5.5 kg (6.9%) with diet and exercise, respectively. Scores of the SF-36 domain 'health change' increased significantly by 8.8 points (95% CI 1.6;16.1) with diet, and by 20.5 points (95% CI 13.2;27.7) with exercise when compared with control. Direct comparison of diet and exercise showed a statistically significantly stronger improvement with exercise. Both intervention groups showed a tendency towards improvements in most other domains, which were more pronounced in the exercise group, but not statistically different from control or each other. In a randomized trial in overweight-to-obese and inactive postmenopausal women a comparable 6%-7% weight loss was achieved by diet-only or mainly by exercise and showed improvements in physical and mental HRQoL domains, but results were not statistically significant in either the diet or exercise group. However, a modest weight loss does lead to a positive change in self-perceived health status. This effect was significantly larger with exercise-induced weight loss than with comparable diet-induced weight loss. ClinicalTrials.gov NCT01511276.

Could habits hold the key to weight loss maintenance? A narrative review.

PubMed

Cleo, G; Isenring, E; Thomas, R; Glasziou, P

2017-10-01

Despite the significance placed on lifestyle interventions for obesity management, most weight loss is followed by weight regain. Psychological concepts of habitual behaviour and automaticity have been suggested as plausible explanations for this overwhelming lack of long-term weight loss success. Interventions that focus on changing an individual's behaviour are not usually successful at changing an individual's habits because they do not incorporate the strategies required to break unhealthy habits and/or form new healthy habits. A narrative review was conducted and describes the theory behind habit formation in relation to weight regain. The review evaluated the effectiveness of using habits as tools to maintain weight loss. Three specific habit-based weight loss programmes are described: '10 Top Tips', 'Do Something Different' and 'Transforming Your Life'. Participants in these interventions achieved significant weight loss compared to a control group or other conventional interventions. Habit-based interventions show promising results in sustaining behaviour change. Weight loss maintenance may benefit from incorporating habit-focused strategies and should be investigated further. © 2017 The British Dietetic Association Ltd.

Motivation for Participating in a Weight Loss Program and Financial Incentives: An Analysis from a Randomized Trial

PubMed Central

Crane, Melissa M.; Tate, Deborah F.; Finkelstein, Eric A.; Linnan, Laura A.

2012-01-01

This analysis investigated if changes in autonomous or controlled motivation for participation in a weight loss program differed between individuals offered a financial incentive for weight loss compared to individuals not offered an incentive. Additionally, the same relationships were tested among those who lost weight and either received or did not receive an incentive. This analysis used data from a year-long randomized worksite weight loss program that randomly assigned employees in each worksite to either a low-intensity weight loss program or the same program plus small financial incentives for weight loss ($5.00 per percentage of initial weight lost). There were no differences in changes between groups on motivation during the study, however, increases in autonomous motivation were consistently associated with greater weight losses. This suggests that the small incentives used in this program did not lead to increases in controlled motivation nor did they undermine autonomous motivation. Future studies are needed to evaluate the magnitude and timing of incentives to more fully understand the relationship between incentives and motivation. PMID:22577524

Resistant starch and energy balance: impact on weight loss and maintenance.

PubMed

Higgins, Janine A

2014-01-01

The obesity epidemic has prompted researchers to find effective weight-loss and maintenance tools. Weight loss and subsequent maintenance are reliant on energy balance--the net difference between energy intake and energy expenditure. Negative energy balance, lower intake than expenditure, results in weight loss whereas positive energy balance, greater intake than expenditure, results in weight gain. Resistant starch has many attributes, which could promote weight loss and/or maintenance including reduced postprandial insulinemia, increased release of gut satiety peptides, increased fat oxidation, lower fat storage in adipocytes, and preservation of lean body mass. Retention of lean body mass during weight loss or maintenance would prevent the decrease in basal metabolic rate and, therefore, the decrease in total energy expenditure, that occurs with weight loss. In addition, the fiber-like properties of resistant starch may increase the thermic effect of food, thereby increasing total energy expenditure. Due to its ability to increase fat oxidation and reduce fat storage in adipocytes, resistant starch has recently been promoted in the popular press as a "weight loss wonder food". This review focuses on data describing the effects of resistant starch on body weight, energy intake, energy expenditure, and body composition to determine if there is sufficient evidence to warrant these claims.

Imposition of physical parameters in dissipative particle dynamics

NASA Astrophysics Data System (ADS)

Mai-Duy, N.; Phan-Thien, N.; Tran-Cong, T.

2017-12-01

In the mesoscale simulations by the dissipative particle dynamics (DPD), the motion of a fluid is modelled by a set of particles interacting in a pairwise manner, and it has been shown to be governed by the Navier-Stokes equation, with its physical properties, such as viscosity, Schmidt number, isothermal compressibility, relaxation and inertia time scales, in fact its whole rheology resulted from the choice of the DPD model parameters. In this work, we will explore the response of a DPD fluid with respect to its parameter space, where the model input parameters can be chosen in advance so that (i) the ratio between the relaxation and inertia time scales is fixed; (ii) the isothermal compressibility of water at room temperature is enforced; and (iii) the viscosity and Schmidt number can be specified as inputs. These impositions are possible with some extra degrees of freedom in the weighting functions for the conservative and dissipative forces. Numerical experiments show an improvement in the solution quality over conventional DPD parameters/weighting functions, particularly for the number density distribution and computed stresses.

Patient and Physician Characteristics Associated with the Provision of Weight Loss Counseling in Primary Care

PubMed Central

Dutton, Gareth R.; Herman, Katharine G.; Tan, Fei; Goble, Mary; Dancer-Brown, Melissa; Van Vessem, Nancy; Ard, Jamy D.

2013-01-01

Background A variety of physician and patient characteristics may influence whether weight loss counseling occurs in primary care encounters. Objectives This study utilized a cross-sectional survey of primary care patients, which examined patient characteristics, physician characteristics, and characteristics of the physician-patient relationship associated with weight loss counseling and recommendations provided by physicians. Participants Participants (N=143, mean age=46.8 years, mean BMI=36.9 kg/m2, 65% Caucasian) were overweight and obese primary care patients participating in a managed care weight loss program. Measures Participants completed self-report surveys in the clinic prior to the initial weight loss session. Surveys included items assessing demographic/background characteristics, weight, height, and a health care questionnaire evaluating whether their physician had recommended weight loss, the frequency of their physicians’ weight loss counseling, and whether their physician had referred them for obesity treatment. Results Patient BMI and physician sex were most consistently associated with physicians’ weight loss counseling practices. Patients seen by female physicians were more likely to be told that they should lose weight, received more frequent obesity counseling, and were more likely to have been referred for obesity treatment by their physician. Length and frequency of physician-patient contacts were unrelated to the likelihood of counseling. Conclusions These findings add to previous evidence suggesting possible differences in the weight loss counseling practices of male and female physicians, although further research is needed to understand this potential difference between physicians. PMID:24743007

Maternal weight loss during exclusive breastfeeding is associated with reduced weight and length gain in daughters of HIV-infected Malawian women.

PubMed

Widen, Elizabeth M; Bentley, Margaret E; Kayira, Dumbani; Chasela, Charles S; Jamieson, Denise J; Tembo, Martin; Soko, Alice; Kourtis, Athena P; Flax, Valerie L; Ellington, Sascha R; van der Horst, Charles M; Adair, Linda S

2013-07-01

Maternal weight loss during exclusive breastfeeding may influence the growth of exclusively breast-fed infants through impaired quality or quantity of breast milk. This study evaluated how maternal weight loss from 2 to 24 wk postpartum was related to infant weight and length gain in 1309 lactating HIV-infected mothers and their exclusively breast-fed infants. Malawian mother-infant pairs in the Breastfeeding, Antiretrovirals, and Nutrition Study were randomized with a 2 × 3 factorial design to a 2-arm nutritional intervention with a lipid-based nutrient supplement (LNS), meeting nutritional needs of lactation, or no LNS and a 3-arm antiretroviral (ARV) intervention (maternal, infant, or no ARV regimen). Linear regression models were used to relate maternal weight loss (weight loss vs. no weight loss) to infant weight and length gain from birth to 24 mo, stratifying by gender and controlling for maternal BMI at 2 wk (mean ± SD: 23.2 ± 3.0 kg/m(2)) and interacting maternal BMI with weight loss. In adjusted models, compared with daughters of women who did not lose weight, length and weight gain were lower in daughters whose mothers had a lower BMI at 2 wk postpartum coupled with the weight loss. For example, among mothers with an initial BMI of 18 kg/m(2), daughters of those who lost weight gained less weight [β = -0.29 kg (95% CI: -0.53, -0.06)] and length [β = -0.88 cm (95% CI: -1.52, -0.23)] from birth to 24 wk than daughters of those who gained weight. Though effects were only observed in girls, suggesting possible gender differences in suckling and feeding behavior, these findings indicate that maternal weight loss with low energy reserves represents a risk factor for poor infant growth outcomes.

Maternal Weight Loss during Exclusive Breastfeeding Is Associated with Reduced Weight and Length Gain in Daughters of HIV-Infected Malawian Women123

PubMed Central

Widen, Elizabeth M.; Bentley, Margaret E.; Kayira, Dumbani; Chasela, Charles S.; Jamieson, Denise J.; Tembo, Martin; Soko, Alice; Kourtis, Athena P.; Flax, Valerie L.; Ellington, Sascha R.; van der Horst, Charles M.; Adair, Linda S.

2013-01-01

Maternal weight loss during exclusive breastfeeding may influence the growth of exclusively breast-fed infants through impaired quality or quantity of breast milk. This study evaluated how maternal weight loss from 2 to 24 wk postpartum was related to infant weight and length gain in 1309 lactating HIV-infected mothers and their exclusively breast-fed infants. Malawian mother-infant pairs in the Breastfeeding, Antiretrovirals, and Nutrition Study were randomized with a 2 × 3 factorial design to a 2-arm nutritional intervention with a lipid-based nutrient supplement (LNS), meeting nutritional needs of lactation, or no LNS and a 3-arm antiretroviral (ARV) intervention (maternal, infant, or no ARV regimen). Linear regression models were used to relate maternal weight loss (weight loss vs. no weight loss) to infant weight and length gain from birth to 24 mo, stratifying by gender and controlling for maternal BMI at 2 wk (mean ± SD: 23.2 ± 3.0 kg/m2) and interacting maternal BMI with weight loss. In adjusted models, compared with daughters of women who did not lose weight, length and weight gain were lower in daughters whose mothers had a lower BMI at 2 wk postpartum coupled with the weight loss. For example, among mothers with an initial BMI of 18 kg/m2, daughters of those who lost weight gained less weight [β = −0.29 kg (95% CI: −0.53, −0.06)] and length [β = −0.88 cm (95% CI: −1.52, −0.23)] from birth to 24 wk than daughters of those who gained weight. Though effects were only observed in girls, suggesting possible gender differences in suckling and feeding behavior, these findings indicate that maternal weight loss with low energy reserves represents a risk factor for poor infant growth outcomes. PMID:23700341

Cardiometabolic risk after weight loss and subsequent weight regain in overweight and obese postmenopausal women.

PubMed

Beavers, Daniel P; Beavers, Kristen M; Lyles, Mary F; Nicklas, Barbara J

2013-06-01

Little is known about the effect of intentional weight loss and subsequent weight regain on cardiometabolic risk factors in older adults. The objective of this study was to determine how cardiometabolic risk factors change in the year following significant intentional weight loss in postmenopausal women, and if observed changes were affected by weight and fat regain. Eighty, overweight and obese, older women (age = 58.8±5.1 years) were followed through a 5-month weight loss intervention and a subsequent 12-month nonintervention period. Body weight/composition and cardiometabolic risk factors (blood pressure; total, high-density lipoprotein, and low-density lipoprotein cholesterol; triglycerides; fasting glucose and insulin; and Homeostatic Model Assessment of Insulin Resistance) were analyzed at baseline, immediately postintervention, and 6- and 12-months postintervention. Average weight loss during the 5-month intervention was 11.4±4.1kg and 31.4% of lost weight was regained during the 12-month follow-up. On average, all risk factor variables were significantly improved with weight loss but regressed toward baseline values during the year subsequent to weight loss. Increases in total cholesterol, triglycerides, glucose, insulin, and Homeostatic Model Assessment of Insulin Resistance during the postintervention follow-up were significantly (p < .05) associated with weight and fat mass regain. Among women who regained weight, model-adjusted total cholesterol (205.8±4.0 vs 199.7±2.9mg/dL), low-density lipoprotein cholesterol (128.4±3.4 vs 122.7±2.4mg/dL), insulin (12.6±0.7 vs 11.4±0.7mg/dL), and Homeostatic Model Assessment of Insulin Resistance (55.8±3.5 vs 50.9±3.7mg/dL) were higher at follow-up compared with baseline. For postmenopausal women, even partial weight regain following intentional weight loss is associated with increased cardiometabolic risk. Conversely, maintenance of or continued weight loss is associated with sustained improvement in the cardiometabolic profile.

Relationship between volition, physical activity and weight loss maintenance: Study rationale, design, methods and baseline characteristics.

PubMed

Dandanell, Sune; Elbe, Anne-Marie; Pfister, Gertrud; Elsborg, Peter; W Helge, Jørn

2017-05-01

To investigate the relationship between volition, physical activity and weight loss maintenance. We recruited 84 sedentary (maximal oxygen uptake: 25 ± 5 ml/min), overweight and obese (Body mass index (BMI) 38 ± 7 m/h 2 , fat 44 ± 7 %) women ( n = 55) and men ( n = 29) for an interdisciplinary prospective study with follow-up. The change in lifestyle and weight loss is promoted via a 3-month intensive lifestyle intervention at a private health school. The intervention consists of supervised training (1-3 hours/day), a healthy hypo-caloric diet (-500 to -700 kCal/day) and education in healthy lifestyle in classes/groups. The participants' body weight and composition (Dual Energy X-ray absorptiometry), volitional skills (questionnaire), physical activity level (heart rate accelerometer/questionnaire) and maximal oxygen uptake (indirect calorimetry) are to be monitored before, after, and 3 and 12 months after the intervention. At the 12-month follow-up, three different groups will be established: Clinical weight loss maintenance (> 10% weight loss from baseline), moderate weight loss maintenance (1-10% weight loss) and no weight loss (or weight regain). A linear mixed model analysis will be used to compare levels of volitional skills, physical activity and maximal oxygen uptake over time, between the three groups. Correlational analyses will be used to investigate possible associations between volition, maximal oxygen uptake, physical activity level and weight loss maintenance. If specific volitional skills are identified as predictors of adherence to physical activity and success in clinical weight loss maintenance, these can be trained in future intensive lifestyle interventions in order to optimize the success rate.

Tweeting it off: characteristics of adults who tweet about a weight loss attempt

PubMed Central

Pagoto, Sherry; Schneider, Kristin L; Evans, Martinus; Waring, Molly E; Appelhans, Brad; Busch, Andrew M; Whited, Matthew C; Thind, Herpreet; Ziedonis, Michelle

2014-01-01

Objective The purpose of this study was to describe adults who use Twitter during a weight loss attempt and to compare the positive and negative social influences they experience from their offline friends, online friends, and family members. Materials and methods Participants (N=100, 80% female, mean age=37.65, SD=8.42) were recruited from Twitter. They completed a brief survey about their experiences discussing their weight loss attempt with their online and offline friends and provided responses to open-ended questions on the benefits and drawbacks of discussing weight on Twitter, Facebook, and weight-specific social networks. Results Participants rated their connections on Twitter and weight loss-specific social networks to be significantly greater sources of positive social influence for their weight loss (F(3)=3.47; p<0.001) and significantly lesser sources of negative social influence (F(3)=40.39 and F(3)=33.68 (both p<0.001)) than their offline friends, family, and Facebook friends. Greater positive social influence from Twitter and Facebook friends was associated with greater weight loss in participants’ most recent weight loss attempt (r=0.30, r=0.32; p<0.01). The most commonly reported benefits of tweeting about weight loss include social support, information, and accountability. The most common drawbacks reported are that interactions were too brief and lacked personal connection. Discussion People who discuss their weight loss on Twitter report more social support and less negativity from their Twitter friends than their Facebook friends and in-person relationships. Conclusions Online social networks should be explored as a tool for connecting patients who lack weight loss social support from their in-person relationships. PMID:24928175

A smartphone-supported weight loss program: design of the ENGAGED randomized controlled trial.

PubMed

Pellegrini, Christine A; Duncan, Jennifer M; Moller, Arlen C; Buscemi, Joanna; Sularz, Alyson; DeMott, Andrew; Pictor, Alex; Pagoto, Sherry; Siddique, Juned; Spring, Bonnie

2012-11-30

Obesity remains a major public health challenge, demanding cost-effective and scalable weight management programs. Delivering key treatment components via mobile technology offers a potential way to reduce expensive in-person contact, thereby lowering the cost and burden of intensive weight loss programs. The ENGAGED study is a theory-guided, randomized controlled trial designed to examine the feasibility and efficacy of an abbreviated smartphone-supported weight loss program. Ninety-six obese adults (BMI 30-39.9 kg/m2) will be randomized to one of three treatment conditions: (1) standard behavioral weight loss (STND), (2) technology-supported behavioral weight loss (TECH); or (3) self-guided behavioral weight loss (SELF). All groups will aim to achieve a 7% weight loss goal by reducing calorie and fat intake and progressively increasing moderate intensity physical activity to 175 minutes/week. STND and TECH will attend 8 group sessions and receive regular coaching calls during the first 6 months of the intervention; SELF will receive the Group Lifestyle Balance Program DVD's and will not receive coaching calls. During months 1-6, TECH will use a specially designed smartphone application to monitor dietary intake, body weight, and objectively measured physical activity (obtained from a Blue-tooth enabled accelerometer). STND and SELF will self-monitor on paper diaries. Linear mixed modeling will be used to examine group differences on weight loss at months 3, 6, and 12. Self-monitoring adherence and diet and activity goal attainment will be tested as mediators. ENGAGED is an innovative weight loss intervention that integrates theory with emerging mobile technologies. We hypothesize that TECH, as compared to STND and SELF, will result in greater weight loss by virtue of improved behavioral adherence and goal achievement. NCT01051713.

Results of the Exercise and Nutrition to Enhance Recovery and Good Health for You (ENERGY) Trial: A Behavioral Weight Loss Intervention in Overweight or Obese Breast Cancer Survivors

PubMed Central

Rock, Cheryl L.; Flatt, Shirley W.; Byers, Tim E.; Colditz, Graham A.; Demark-Wahnefried, Wendy; Ganz, Patricia A.; Wolin, Kathleen Y.; Elias, Anthony; Krontiras, Helen; Liu, Jingxia; Naughton, Michael; Pakiz, Bilgé; Parker, Barbara A.; Sedjo, Rebecca L.; Wyatt, Holly

2015-01-01

Purpose Obesity increases risk for all-cause and breast cancer mortality and comorbidities in women who have been diagnosed and treated for breast cancer. The Exercise and Nutrition to Enhance Recovery and Good Health for You (ENERGY) study is the largest weight loss intervention trial among survivors of breast cancer to date. Methods In this multicenter trial, 692 overweight/obese women who were, on average, 2 years since primary treatment for early-stage breast cancer were randomly assigned to either a group-based behavioral intervention, supplemented with telephone counseling and tailored newsletters, to support weight loss or a less intensive control intervention and observed for 2 years. Weight and blood pressure were measured at 6, 12, 18, and 24 months. Longitudinal mixed models were used to analyze change over time. Results At 12 months, mean weight loss was 6.0% of initial weight in the intervention group and 1.5% in the control group (P < .001). At 24 months, mean weight loss in the intervention and control groups was 3.7% and 1.3%, respectively (P < .001). Favorable effects of the intervention on physical activity and blood pressure were observed. The weight loss intervention was more effective among women older than 55 years than among younger women. Conclusion A behavioral weight loss intervention can lead to clinically meaningful weight loss in overweight/obese survivors of breast cancer. These findings support the need to conduct additional studies to test methods that support sustained weight loss and to examine the potential benefit of intentional weight loss on breast cancer recurrence and survival. PMID:26282657

Self-esteem outcomes over a summer camp for obese youth.

PubMed

McGregor, S; McKenna, J; Gately, P; Hill, A J

2016-12-01

Variation in the existing literature on the psychosocial benefits of weight loss in obese youth results, in part, from methodological limitations and modest weight loss. Accordingly, this research assessed perceived self-competence and low self-esteem during an intensive weight loss programme in a large sample of obese youth and related these to starting weight, gender and weight loss. Over 4 years, 303 obese male and female adolescents (body mass index [BMI] 34.3 kg m -2 , BMI standard deviation score 2.99; 14.7 years) attended a residential weight loss camp for a mean duration of 31 d. Outcome variables included dimensional self-esteem (Harter) and weight change over the camp. At the start of camp, obese youth scored highest on social acceptance and lowest on physical appearance and athletic competence. Global self-worth and most domains of self-competence improved significantly over the intervention. The proportion with low global self-worth reduced from 35% to 16%, but there was little change in the proportion reporting high self-competence (23%). Mean weight loss was -5.5 kg (BMI standard deviation scores -0.25) with boys and those heaviest at the start losing most. Weight loss was significantly correlated with improved physical appearance (r = 0.13) and athletic competence (r = 0.19), but not global self-worth. This intensive weight loss intervention yielded significant psychological benefit, especially in self-competence and among individuals achieving most weight loss. The weak association with weight loss suggests the influence of other contributing environmental or social features that should be the focus of further research. © 2016 World Obesity Federation.

Results of the Exercise and Nutrition to Enhance Recovery and Good Health for You (ENERGY) Trial: A Behavioral Weight Loss Intervention in Overweight or Obese Breast Cancer Survivors.

PubMed

Rock, Cheryl L; Flatt, Shirley W; Byers, Tim E; Colditz, Graham A; Demark-Wahnefried, Wendy; Ganz, Patricia A; Wolin, Kathleen Y; Elias, Anthony; Krontiras, Helen; Liu, Jingxia; Naughton, Michael; Pakiz, Bilgé; Parker, Barbara A; Sedjo, Rebecca L; Wyatt, Holly

2015-10-01

Obesity increases risk for all-cause and breast cancer mortality and comorbidities in women who have been diagnosed and treated for breast cancer. The Exercise and Nutrition to Enhance Recovery and Good Health for You (ENERGY) study is the largest weight loss intervention trial among survivors of breast cancer to date. In this multicenter trial, 692 overweight/obese women who were, on average, 2 years since primary treatment for early-stage breast cancer were randomly assigned to either a group-based behavioral intervention, supplemented with telephone counseling and tailored newsletters, to support weight loss or a less intensive control intervention and observed for 2 years. Weight and blood pressure were measured at 6, 12, 18, and 24 months. Longitudinal mixed models were used to analyze change over time. At 12 months, mean weight loss was 6.0% of initial weight in the intervention group and 1.5% in the control group (P<.001). At 24 months, mean weight loss in the intervention and control groups was 3.7% and 1.3%, respectively (P<.001). Favorable effects of the intervention on physical activity and blood pressure were observed. The weight loss intervention was more effective among women older than 55 years than among younger women. A behavioral weight loss intervention can lead to clinically meaningful weight loss in overweight/obese survivors of breast cancer. These findings support the need to conduct additional studies to test methods that support sustained weight loss and to examine the potential benefit of intentional weight loss on breast cancer recurrence and survival. © 2015 by American Society of Clinical Oncology.

Food addiction in adults seeking weight loss treatment. Implications for psychosocial health and weight loss.

PubMed

Burmeister, Jacob M; Hinman, Nova; Koball, Afton; Hoffmann, Debra A; Carels, Robert A

2013-01-01

The present study examined food addiction symptomology and its relationship to eating pathology and psychological distress among adults seeking weight loss treatment. A primary interest was an examination of the relationship between food addiction symptoms and short-term weight loss. Adults beginning a behavioral weight loss program (N=57) were given the Yale Food Addiction Scale (YFAS) as well as measures of psychological distress, disordered eating, weight bias, and weight-focused attitudes. Weight loss was measured after 7 weeks. Severity of food addiction was related to increased depression, emotional eating, binge eating, anti-fat attitudes, internalized weight bias, body shame, and low eating self-efficacy, but not body satisfaction. Increased food addiction symptomology was also related to less weight lost at 7 weeks. Findings suggest that individuals attempting to lose weight while combating symptoms of food addiction may be especially prone to eating-related pathologies, internalized weight bias, and body shame. Importantly, findings provide evidence that food addiction may undermine efforts to lose weight. The pathology associated with addiction (e.g., tolerance, withdrawal) could make the adoption of more healthful eating habits especially difficult. Copyright © 2012 Elsevier Ltd. All rights reserved.

Revisional bariatric surgery: who, what, where, and when?

PubMed

Radtka, John F; Puleo, Frances J; Wang, Li; Cooney, Robert N

2010-01-01

Revisional bariatric surgery (RBS) outcomes have been poorly characterized. We compared the RBS and primary bariatric surgery (PBS) outcomes at the Penn State Milton S. Hershey Medical Center in the United States. A total of 72 RBS cases from 2000 to 2007 were reviewed and grouped by indication: failure of weight loss, gastrojejunal complications, or other. The RBS patients were compared with the 856 PBS patients who underwent Roux-en-Y gastric bypass. The mean follow-up time was 12.6 ± 1.2 months for the RBS group and 16 ± 0.5 months for the PBS group. Weight loss was analyzed as the kilograms lost and patients with ≥ 50% excess body weight loss (EBWL). Outcomes included mortality, leaks, surgical site infections, and length of stay. The weight loss was 23 ± 2.8 kg after RBS and 41.3 ± 0.7 kg after PBS (P <.05 versus PBS). The post-RBS weight loss varied by surgical indication: failure of weight loss, 27.1 ± 2 kg; gastrojejunal complications, 8.7 ± 3.4 kg; and other 23.5 ± 10.6 kg. Also, 29% of the RBS patients had ≥ 50% excess body weight loss (versus the prerevision weight) and 61% (versus the initial weight) compared with 52.7% after PBS. Only age ≤ 50 years was associated with ≥ 50% excess body weight loss after RBS for the failure of weight loss group. No RBS patients died. However, leaks, surgical site infections, and length of stay were increased after RBS. The results of our study have shown that weight loss after RBS varies with the surgical indication and is affected by age >50 years. Although the RBS patients had decreased weight loss and increased complications compared with the PBS patients, ≥ 50% EBWL was achieved by a significant number of RBS patients. Copyright © 2010 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

A losing battle: weight regain does not restore weight loss-induced bone loss in postmenopausal women.

PubMed

Villalon, Karen L; Gozansky, Wendolyn S; Van Pelt, Rachael E; Wolfe, Pam; Jankowski, Catherine M; Schwartz, Robert S; Kohrt, Wendy M

2011-12-01

Previously, we reported significant bone mineral density (BMD) loss in postmenopausal women after modest weight loss. It remains unclear whether the magnitude of BMD change in response to weight loss is appropriate (i.e., proportional to weight loss) and whether BMD is recovered with weight regain. We now report changes in BMD after a 1-year follow-up. Subjects (n = 23) in this secondary analysis were postmenopausal women randomized to placebo as part of a larger trial. They completed a 6-month exercise-based weight loss program and returned for follow-up at 18 months. Dual-energy X-ray absorptiometry (DXA) was performed at baseline, 6, and 18 months. At baseline, subjects were aged 56.8 ± 5.4 years (mean ± s.d.), 10.0 ± 9.2 years postmenopausal, and BMI was 29.6 ± 4.0 kg/m(2). They lost 3.9 ± 3.5 kg during the weight loss intervention. During follow-up, they regained 2.9 ± 3.9 kg. Six months of weight loss resulted in a significant decrease in lumbar spine (LS) (-1.7 ± 3.5%; P = 0.002) and hip (-0.04 ± 3.5%; P = 0.03) BMD that was accompanied by an increase in a biomarker of bone resorption (serum C-terminal telopeptide of type I collagen, CTX: 34 ± 54%; P = 0.08). However, weight regain was not associated with LS (0.05 ± 3.8%; P = 0.15) or hip (-0.6 ± 3.0%; P = 0.81) bone regain or decreased bone resorption (CTX: -3 ± 37%; P = 0.73). The findings suggest that BMD lost during weight reduction may not be fully recovered with weight regain in hormone-deficient, postmenopausal women. Future studies are needed to identify effective strategies to prevent bone loss during periods of weight loss.

Weight loss and dropout during a commercial weight-loss program including a very-low-calorie diet, a low-calorie diet, or restricted normal food: observational cohort study.

PubMed

Hemmingsson, Erik; Johansson, Kari; Eriksson, Jonas; Sundström, Johan; Neovius, Martin; Marcus, Claude

2012-11-01

The effectiveness of commercial weight-loss programs consisting of very-low-calorie diets (VLCDs) and low-calorie diets (LCDs) is unclear. The aim of the study was to quantify weight loss and dropout during a commercial weight-loss program in Sweden (Itrim; cost: $1300/€1000; all participants paid their own fee). This observational cohort study linked commercial weight-loss data with National Health Care Registers. Weight loss was induced with a 500-kcal liquid-formula VLCD [n = 3773; BMI (in kg/m(2)): 34 ± 5 (mean ± SD); 80% women; 45 ± 12 y of age (mean ± SD)], a 1200-1500-kcal formula and food-combination LCD (n = 4588; BMI: 30 ± 4; 86% women; 50 ± 11 y of age), and a 1500-1800-kcal/d restricted normal-food diet (n = 676; BMI: 29 ± 5; 81% women; 51 ± 12 y of age). Maintenance strategies included exercise and a calorie-restricted diet. Weight loss was analyzed by using an intention-to-treat analysis (baseline substitution). After 1 y, mean (±SD) weight changes were -11.4 ± 9.1 kg with the VLCD (18% dropout), -6.8 ± 6.4 kg with the LCD (23% dropout), and -5.1 ± 5.9 kg with the restricted normal-food diet (26% dropout). In an adjusted analysis, the VLCD group lost 2.8 kg (95% CI: 2.5, 3.2) and 3.8 kg (95% CI: 3.2, 4.5) more than did the LCD and restricted normal-food groups, respectively. A high baseline BMI and rapid initial weight loss were both independently associated with greater 1-y weight loss (P < 0.001). Younger age and low initial weight loss predicted an increased dropout rate (P < 0.001). Treatment of depression (OR: 1.4; 95% CI: 1.1, 1.9) and psychosis (OR: 2.6; 95% CI: 1.1, 6.3) were associated with an increased dropout rate in the VLCD group. A commercial weight-loss program, particularly one using a VLCD, was effective at reducing body weight in self-selected, self-paying adults.

Does bone loss begin after weight loss ends? Results two years after weight loss or regain in postmenopausal women

PubMed Central

Von Thun, Nancy L.; Sukumar, Deeptha; Heymsfield, Steven B.; Shapses, Sue A.

2016-01-01

Objective Short-term weight loss is accompanied by bone loss in postmenopausal women. The longer-term impact on bone in the reduced overweight/obese woman compared to those who regain their weight was examined in this study using a case-control design. Methods Postmenopausal women (n = 42, body mass index of 28.3 ± 2.8 kg/m2; 60.7 ± 5.5 y) were recruited 2 years after the start of a 6 month weight loss trial and those who maintained their weight (WL-M) were matched to a cohort who regained weight (WL-R). Serum hormones and bone markers were measured in a subset. Bone mineral density (BMD) at the femoral neck (FN), trochanter, spine, radius, and total body and soft tissue composition were taken at baseline, 0.5 and 2 years. Results During WL, both groups lost 9.3 ± 3.4% body weight with no significant difference between groups. After weight loss, weight change was −0.1 ± 2.7 % and 6.0 ± 3.3% in the WL-M (n=22) and WL-R (n=20) groups, respectively. After 2 years, both groups lost BMD at the FN and trochanter (p ≤ 0.01), whereas only the WL-M group reduced BMD at the 1/3 radius (p < 0.001). There was a greater BMD loss at the trochanter (−6.8 ± 5.7%) and the 1/3 radius (−4.5 ± 3.3%) in the WL-M compared to the WL-R group after 2 years. Multiple linear regression showed that change in leg fat mass (but not trunk fat) contributed to trochanter BMD loss (p <0.05). Conclusions After 2 years, there is no BMD recovery of weight reduction-induced bone loss, irrespective of weight-regain. These data suggest that the period after weight loss may be an important point in time to prevent bone loss for both those who maintain or regain weight. PMID:24149920

Systems evaluation of thermal bus concepts

NASA Technical Reports Server (NTRS)

Stalmach, D. D.

1982-01-01

Thermal bus concepts, to provide a centralized thermal utility for large, multihundred kilowatt space platforms, were studied and the results are summarized. Concepts were generated, defined, and screened for inclusion in system level thermal bus trades. Parametric trade studies were conducted in order to define the operational envelope, performance, and physical characteristics of each. Two concepts were selected as offering the most promise for thermal bus development. All of four concepts involved two phase flow in order to meet the required isothermal nature of the thermal bus. Two of the concepts employ a mechanical means to circulate the working fluid, a liquid pump in one case and a vapor compressor in another. Another concept utilizes direct osmosis as the driving force of the thermal bus. The fourth concept was a high capacity monogroove heat pipe. After preliminary sizing and screening, three of these concepts were selected to carry into the trade studies. The monogroove heat pipe concept was deemed unsuitable for further consideration because of its heat transport limitations. One additional concept utilizing capillary forces to drive the working fluid was added. Parametric system level trade studies were performed. Sizing and weight calculations were performed for thermal bus sizes ranging from 5 to 350 kW and operating temperatures in the range of 4 to 120 C. System level considerations such as heat rejection and electrical power penalties and interface temperature losses were included in the weight calculations.

Associations among endocrine, inflammatory, and bone markers, body composition and weight loss induced bone loss.

PubMed

Labouesse, Marie A; Gertz, Erik R; Piccolo, Brian D; Souza, Elaine C; Schuster, Gertrud U; Witbracht, Megan G; Woodhouse, Leslie R; Adams, Sean H; Keim, Nancy L; Van Loan, Marta D

2014-07-01

Weight loss reduces co-morbidities of obesity, but decreases bone mass. Our aims were to (1) determine if adequate dairy intake attenuates weight loss-induced bone loss; (2) evaluate the associations of endocrine, inflammatory and bone markers, anthropometric and other parameters to bone mineral density and content (BMD, BMC) pre- and post-weight loss; and (3) model the contribution of these variables to post weight-loss BMD and BMC. Overweight/obese women (BMI: 28-37 kg/m2) were enrolled in an energy reduced (-500 kcal/d; -2092 kJ/d) diet with adequate dairy (AD: 3-4 servings/d; n=25, 32.2±8.8 years) or low dairy (LD: ≤1 serving/d; n=26, 31.7±8.4 years). BMD, BMC and body composition were measured by DXA. Bone markers (CTX, PYD, BAP, OC), endocrine (PTH, vitamin D, leptin, adiponectin, ghrelin, amylin, insulin, GLP-1, PAI-1, HOMA) and inflammatory markers (CRP, IL1-β, IL-6, IL-8, TNF-α, cortisol) were measured in serum or plasma. PA was assessed by accelerometry. Following weight loss, AD intake resulted in significantly greater (p=0.004) lumbar spine BMD and serum osteocalcin (p=0.004) concentration compared to LD. Pre- and post-body fat was negatively associated with hip and lumbar spine BMC (r=-0.28, p=0.04 to -0.45, p=0.001). Of note were the significant negative associations among bone markers and IL-1β, TNFα and CRP ranging from r = -0.29 (p=0.04) to r = -0.34 (p=0.01); magnitude of associations did not change with weight loss. Adiponectin was negatively related to change in osteocalcin. Factor analysis resulted in 8 pre- and post-weight loss factors. Pre-weight loss factors accounted for 13.7% of the total variance in pre-weight loss hip BMD; post-weight loss factors explained 19.6% of the total variance in post-weight loss hip BMD. None of the factors contributed to the variance in lumbar spine BMD. AD during weight loss resulted in higher lumbar spine BMD and osteocalcin compared to LD. Significant negative associations were observed between bone and inflammatory markers suggesting that inflammation suppresses bone metabolism. Using factor analysis, 19.6% of total variance in post-weight loss hip BMD could be explained by endocrine, immune, and anthropometric variables, but not lumbar spine BMD. Published by Elsevier Inc.

Associations among Endocrine, Inflammatory, and Bone Markers, Body Composition and Physical Activity to Weight Loss Induced Bone Loss

PubMed Central

Labouesse, Marie A.; Gertz, Erik R.; Piccolo, Brian D.; Souza, Elaine C.; Schuster, Gertrud U.; Witbracht, Megan G.; Woodhouse, Leslie R.; Adams, Sean H.; Keim, Nancy L.; Van Loan, Marta D.

2015-01-01

INTRODUCTION Weight loss reduces co-morbidities of obesity, but decreases bone mass. PURPOSE Our aims were to 1) determine if adequate dairy intake attenuates weight loss-induced bone loss; 2) evaluate the associations of endocrine, inflammatory and bone markers, anthropometric and other parameters to bone mineral density and content (BMD, BMC) pre- and post-weight loss; 3) model the contribution of these variables to post weight-loss BMD and BMC METHODS Overweight/obese women (BMI: 28–37 kg/m2) were enrolled in an energy reduced (−500 kcal/d; −2092 kJ/d) diet with adequate dairy (AD: 3–4 servings/d; n=25, 32.2 ± 8.8y) or low dairy (LD: ≤ 1 serving/d; n=26, 31.7 ± 8.4 y). BMD, BMC and body composition were measured by DXA. Bone markers (CTX, PYD, BAP, OC), endocrine (PTH, vitamin D, leptin, adiponectin, ghrelin, amylin, insulin, GLP-1, PAI-1, HOMA) and inflammatory markers (CRP, IL1-β, IL-6, IL-8, TNF-α, cortisol) were measured in serum or plasma. PA was assessed by accelerometry. RESULTS Following weight loss, AD intake resulted in significantly greater (p= 0.004) lumbar spine BMD and serum osteocalcin (p=0.004) concentration compared to LD. Pre- and post- body fat were negatively associated with hip and lumbar spine BMC (r= −0.28, p=0.04 to −0.45, p=0.001). Of note were the significant negative associations among bone markers and IL-1β, TNFα and CRP ranging from r = −0.29 (p=0.04) to r = −0.34 (p=0.01); magnitude of associations did not change with weight loss. Adiponectin was negatively related to change in osteocalcin. Factor analysis resulted in 8 pre- and post-weight loss Factors. Pre-weight loss Factors accounted for 13.7% of the total variance in pre-weight loss hip BMD; post-weight loss Factors explained 19.6% of the total variance in post-weight loss hip BMD. None of the Factors contributed to the variance in lumbar spine BMD. CONCLUSION AD during weight loss resulted in higher lumbar spine BMD and osteocalcin compared to LD. Significant negative associations were observed between bone and inflammatory markers suggesting inflammation suppresses bone metabolism. Using Factor Analysis, 19.6% of total variance in post-weight loss hip BMD could be explained by endocrine, immune, and anthropometric variables, but not lumbar spine BMD. PMID:24709689

Physiological adaptations to weight loss and factors favouring weight regain

PubMed Central

Greenway, F L

2015-01-01

Obesity is a major global health problem and predisposes individuals to several comorbidities that can affect life expectancy. Interventions based on lifestyle modification (for example, improved diet and exercise) are integral components in the management of obesity. However, although weight loss can be achieved through dietary restriction and/or increased physical activity, over the long term many individuals regain weight. The aim of this article is to review the research into the processes and mechanisms that underpin weight regain after weight loss and comment on future strategies to address them. Maintenance of body weight is regulated by the interaction of a number of processes, encompassing homoeostatic, environmental and behavioural factors. In homoeostatic regulation, the hypothalamus has a central role in integrating signals regarding food intake, energy balance and body weight, while an ‘obesogenic' environment and behavioural patterns exert effects on the amount and type of food intake and physical activity. The roles of other environmental factors are also now being considered, including sleep debt and iatrogenic effects of medications, many of which warrant further investigation. Unfortunately, physiological adaptations to weight loss favour weight regain. These changes include perturbations in the levels of circulating appetite-related hormones and energy homoeostasis, in addition to alterations in nutrient metabolism and subjective appetite. To maintain weight loss, individuals must adhere to behaviours that counteract physiological adaptations and other factors favouring weight regain. It is difficult to overcome physiology with behaviour. Weight loss medications and surgery change the physiology of body weight regulation and are the best chance for long-term success. An increased understanding of the physiology of weight loss and regain will underpin the development of future strategies to support overweight and obese individuals in their efforts to achieve and maintain weight loss. PMID:25896063

Weight loss in the healthy elderly might be a non-cognitive sign of preclinical Alzheimer's disease.

PubMed

Jimenez, Amanda; Pegueroles, Jordi; Carmona-Iragui, María; Vilaplana, Eduard; Montal, Victor; Alcolea, Daniel; Videla, Laura; Illán-Gala, Ignacio; Pané, Adriana; Casajoana, Anna; Belbin, Olivia; Clarimón, Jordi; Moizé, Violeta; Vidal, Josep; Lleó, Alberto; Fortea, Juan; Blesa, Rafael

2017-12-01

Weight loss has been proposed as a sign of pre-clinical Alzheimer Disease (AD). To test this hypothesis, we have evaluated the association between longitudinal changes in weight trajectories, cognitive performance, AD biomarker profiles and brain structure in 363 healthy controls from the Alzheimer´s Disease Neuroimaging Initiative (mean follow-up 50.5±30.5 months). Subjects were classified according to body weight trajectory into a weight loss group (WLG; relative weight loss ≥ 5%) and a non-weight loss group (non-WLG; relative weight loss < 5%). Linear mixed effects models were used to estimate the effect of body weight changes on ADAS-Cognitive score across time. Baseline CSF tau/AΔ 42 ratio and AV45 PET uptake were compared between WLG and non-WLG by analysis of covariance. Atrophy maps were compared between groups at baseline and longitudinally at a 2-year follow-up using Freesurfer. WLG showed increased baseline levels of cerebrospinal fluid tau/AΔ 42 ratio, increased PET amyloid uptake and diminished cortical thickness at baseline. WLG also showed faster cognitive decline and faster longitudinal atrophy. Our data support weight loss as a non-cognitive manifestation of pre-clinical AD.

Weight loss in the healthy elderly might be a non-cognitive sign of preclinical Alzheimer's disease

PubMed Central

Carmona-Iragui, María; Vilaplana, Eduard; Montal, Victor; Alcolea, Daniel; Videla, Laura; Illán-Gala, Ignacio; Pané, Adriana; Casajoana, Anna; Belbin, Olivia; Clarimón, Jordi; Moizé, Violeta; Vidal, Josep; Lleó, Alberto; Fortea, Juan; Blesa, Rafael

2017-01-01

Weight loss has been proposed as a sign of pre-clinical Alzheimer Disease (AD). To test this hypothesis, we have evaluated the association between longitudinal changes in weight trajectories, cognitive performance, AD biomarker profiles and brain structure in 363 healthy controls from the Alzheimer´s Disease Neuroimaging Initiative (mean follow-up 50.5±30.5 months). Subjects were classified according to body weight trajectory into a weight loss group (WLG; relative weight loss ≥ 5%) and a non-weight loss group (non-WLG; relative weight loss < 5%). Linear mixed effects models were used to estimate the effect of body weight changes on ADAS-Cognitive score across time. Baseline CSF tau/AΔ42 ratio and AV45 PET uptake were compared between WLG and non-WLG by analysis of covariance. Atrophy maps were compared between groups at baseline and longitudinally at a 2-year follow-up using Freesurfer. WLG showed increased baseline levels of cerebrospinal fluid tau/AΔ42 ratio, increased PET amyloid uptake and diminished cortical thickness at baseline. WLG also showed faster cognitive decline and faster longitudinal atrophy. Our data support weight loss as a non-cognitive manifestation of pre-clinical AD. PMID:29285207

Social Media–Promoted Weight Loss Among an Occupational Population: Cohort Study Using a WeChat Mobile Phone App-Based Campaign

PubMed Central

Zhao, Yingying; Li, Zheng; Zhang, Yanyan; Le, Jia; Wang, Lei; Wan, Siyang; Li, Changqing; Li, Yindong

2017-01-01

Background Being overweight and obese are major risk factors for noncommunicable diseases such as cardiovascular diseases. The prevalence of overweight and obesity is high throughout the world and these issues are very serious in the Shunyi District in China. As mobile technologies have rapidly developed, mobile apps such as WeChat are well accepted and have the potential to improve health behaviors. Objective This study aims to evaluate the effectiveness of a mobile app (WeChat) as an intervention on weight loss behavior. Methods This study was conducted among an occupational population from August 2015 to February 2016 in the Shunyi District of Beijing. Before the intervention, the Shunyi District Government released an official document for weight loss to all 134 government agencies and enterprises in Shunyi District. Participants willing to use our official WeChat account were enrolled in a WeChat group and received 6 months of interventions for weight loss; those who were not willing to use the account were in a control group given routine publicity on weight loss. Results In total, 15,310 occupational participants including 3467 participants (22.65%) in the control group and 11,843 participants (77.35%) in the WeChat group were enrolled. Participants in the WeChat group lost more weight (mean 2.09, SD 3.43 kg) than people in the control group (mean 1.78, SD 2.96 kg), and the difference in mean weight loss between the two groups for males was significant based on the stratification of age and educational level. To control for confounding factors and to explore the effects of WeChat on weight loss, the propensity score method with a multinominal logistic regression was utilized. For males, this showed that the WeChat group (with both active and inactive subgroups) had a higher probability of maintaining weight, weight loss from 1 to 2 kg, or weight loss more than 2 kg than the control group. However, the control group had higher probability of weight loss from 0 to 1 kg. Being active in WeChat was likely to be associated with weight loss. The more active participants were in the weight loss program via WeChat, the more weight they lost. Conclusions The weight loss intervention campaign based on an official WeChat account focused on an occupation-based population in Shunyi District was effective for males. The more active male participants were in using WeChat, the more weight they lost. There might be no effect or there may even be a negative effect on weight loss for females. Future research should focus on how to improve adherence to the WeChat weight loss interventions, to improve and refine the WeChat content such as developing a variety of materials to attract interest, and to protect personal privacy, especially for females. PMID:29061555

Behavior Change Strategies for Successful Long-Term Weight Loss: Focusing on Dietary and Physical Activity Adherence, Not Weight Loss

ERIC Educational Resources Information Center

Hongu, Nobuko; Kataura, Martha P.; Block, Linda M.

2011-01-01

This article helps Extension professionals guide individuals in a successful long-term weight loss program. A program should focus on behavioral changes (improving eating habits and physical activity), not just weight loss. In order to do this, Extension professionals should implement behavior change strategies that motivate individuals to…

[Specific weight loss in hyper- and hypothyroidism (author's transl)].

PubMed

Schlick, W; Schmid, P; Irsigler, K

1975-02-07

By means of a new method of extremely precise weight measurement (buoyancy scale) it is possible to measure the continuous weight loss of the human body. This weight loss is made up of three components, viz. the weight difference between produced CO2 and consumed O2, water loss through the lungs and transpiration through the skin. In relation to body weight it is called "specific weight loss." This parameter was measured in healthy human subjects and found to be within a relatively narrow range (16.42 plus or minus 2.55 mg/min/kp body weight). In four patients with hypothyroidism the values were very low (5.5 to 8.5 mg/min/kp). An increased specific weight loss was found in patients with hyperthyroidism (38 to 102 mg/min/kp in clinically severe cases). The applicability of this method to examination of thyroid function is discussed. It is compared to the classical method of basal metabolic rate measurement and its advantages are enumerated.

Prospect theory and body mass: characterizing psychological parameters for weight-related risk attitudes and weight-gain aversion.

PubMed

Lim, Seung-Lark; Bruce, Amanda S

2015-01-01

We developed a novel decision-making paradigm that allows us to apply prospect theory in behavioral economics to body mass. 67 healthy young adults completed self-report measures and two decision-making tasks for weight-loss, as well as for monetary rewards. We estimated risk-related preference and loss aversion parameters for each individual, separately for weight-loss and monetary rewards choice data. Risk-seeking tendency for weight-loss was positively correlated with body mass index in individuals who desired to lose body weight, whereas the risk-seeking for momentary rewards was not. Risk-seeking for weight-loss was correlated to excessive body shape preoccupations, while aversion to weight-gain was correlated with self-reports of behavioral involvement for successful weight-loss. We demonstrated that prospect theory can be useful in explaining the decision-making process related to body mass. Applying prospect theory is expected to advance our understanding of decision-making mechanisms in obesity, which might prove helpful for improving healthy choices.

Prospect theory and body mass: characterizing psychological parameters for weight-related risk attitudes and weight-gain aversion

PubMed Central

Lim, Seung-Lark; Bruce, Amanda S.

2015-01-01

We developed a novel decision-making paradigm that allows us to apply prospect theory in behavioral economics to body mass. 67 healthy young adults completed self-report measures and two decision-making tasks for weight-loss, as well as for monetary rewards. We estimated risk-related preference and loss aversion parameters for each individual, separately for weight-loss and monetary rewards choice data. Risk-seeking tendency for weight-loss was positively correlated with body mass index in individuals who desired to lose body weight, whereas the risk-seeking for momentary rewards was not. Risk-seeking for weight-loss was correlated to excessive body shape preoccupations, while aversion to weight-gain was correlated with self-reports of behavioral involvement for successful weight-loss. We demonstrated that prospect theory can be useful in explaining the decision-making process related to body mass. Applying prospect theory is expected to advance our understanding of decision-making mechanisms in obesity, which might prove helpful for improving healthy choices. PMID:25852628

Financial incentive strategies for maintenance of weight loss: results from an internet-based randomized controlled trial.

PubMed

Yancy, William S; Shaw, Pamela A; Wesby, Lisa; Hilbert, Victoria; Yang, Lin; Zhu, Jingsan; Troxel, Andrea; Huffman, David; Foster, Gary D; Wojtanowski, Alexis C; Volpp, Kevin G

2018-05-25

Financial incentives can improve initial weight loss; we examined whether financial incentives can improve weight loss maintenance. Participants aged 30-80 years who lost at least 5 kg during the first 4-6 months in a nationally available commercial weight loss program were recruited via the internet into a three-arm randomized trial of two types of financial incentives versus active control during months 1-6 (Phase I) followed by passive monitoring during months 7-12 (Phase II). Interventions were daily self-weighing and text messaging feedback alone (control) or combined with a lottery-based incentive or a direct incentive. The primary outcome was weight change 6 months after initial weight loss. Secondary outcomes included weight change 12 months after initial weight loss (6 months after cessation of maintenance intervention), and self-reported physical activity and eating behaviors. Of 191 participants randomized, the mean age was 49.0 (SD = 10.5) years and weight loss prior to randomization was 11.4 (4.7) kg; 92% were women and 89% were White. Mean weight changes during the next 6 months (Phase I) were: lottery -3.0 (5.8) kg; direct -2.8 (5.8) kg; and control -1.4 (5.8) kg (all pairwise comparisons p > 0.1). Weight changes through the end of 12 months post-weight loss (Phase II) were: lottery -1.8 (10.5) kg; direct -0.7 (10.7) kg; and control -0.3 (9.4) kg (all pairwise comparisons p > 0.1). The percentages of participants who maintained their weight loss (defined as gaining ≤1.36 kg) were: lottery 79%, direct 76%, and control 67% at 6 months and lottery 66%, direct 62%, and control 59% at 12 months (all pairwise comparisons p > 0.1). At 6 and 12 months after initial weight loss, changes in self-reported physical activity or eating behaviors did not differ across arms. Compared with the active control of daily texting based on daily home weighing, lottery-based and direct monetary incentives provided no additional benefit for weight loss maintenance.

Ethnic differences in weight loss behavior among secondary school students in Beirut: the role of weight perception.

PubMed

Mehio-Sibai, Abla; Kanaan, Nabil; Chaaya, Monique; Rahal, Boushra; Abdullah, Ahmad; Sibai, Tarek

2003-01-01

Assessing the prevalence of weight loss attempts in Beirut, Lebanon, a country characterized by a diversity of ethnic and religious groups and examining the interplay between ethnicity, body mass index (BMI) and weight perception and their relationship to weight loss behavior. A school-based survey of risk behaviors conducted among secondary students (grade 10-12) in 1997. Subjects consisted of 827 boys and girls, aged 15 to 23 years, the majority of whom were Moslems (65.4%). Multiple logistic regression was used to estimate the association between ethnicity and weight perception with the likelihood of trying to lose weight controlling for BMI and a number of potential covariates. The prevalence of weight loss attempts was 19.1% and 42.6% in boys and girls respectively. Christians were more likely to perceive themselves as overweight and to attempt weight loss than Moslems across all BMI levels, however this trend was significant in the underweight category. While controlling for BMI did not change appreciably the results observed, after controlling for weight perception, ethnic differences in weight-loss behavior disappeared. Findings of the study suggest that whereas actual weight may constitute only partially the driving force for differentials by ethnicity, the perception of body weight acts as a mediating factor in the relationship between ethnicity and weight loss behavior. Understanding the disparities in weight management behavior across various adolescent groups is key to develop culturally appropriate educational and intervention programs for the youths.

Long-term weight loss observed with olanzapine orally disintegrating tablets in overweight patients with chronic schizophrenia. A 1 year open-label, prospective trial.

PubMed

Chawla, Bharat; Luxton-Andrew, Heather

2008-04-01

To investigate the long-term weight loss outcomes during usual clinical practice after switching from olanzapine standard oral tablet (SOT) to olanzapine orally disintegrating tablets (ODT). In this open-label prospective study, 26 patients with schizophrenia who were clinically stable on olanzapine SOT treatment were switched to olanzapine ODT. All other aspects of treatment remained constant. Weight was recorded at 3, 6, and 12 months. Patients incurred an average weight loss of 2.7 +/- 0.7 kg (p = 0.001) after switching patients from olanzapine SOT to olanzapine ODT at 12 months. Peak weight loss was observed at 6 months; however, significant weight loss was achieved as early as 3 months. The majority (81.9%) of patients lost weight, while 18.1% had no weight change or weight gain. Body mass index (BMI) significantly decreased by 1.0 +/- 0.3 kg/m(2) (p = 0.001). Interestingly, patients treated with higher doses of olanzapine (> or = 20 mg) incurred a greater weight loss of their body weight (5.6%), compared to those treated with lower doses (< 20 mg), who lost 1.9% of their body weight (p = 0.04). This study demonstrated that, in usual clinical practice, switching patients from olanzapine SOT to olanzapine ODT treatment resulted in significant weight loss that was maintained over 12 months. 2008 John Wiley & Sons, Ltd.

Long-Term Effects of Weight Loss and Exercise on Biomarkers Associated with Angiogenesis.

PubMed

Duggan, Catherine; Tapsoba, Jean de Dieu; Wang, Ching-Yun; Schubert, Karen E Foster; McTiernan, Anne

2017-12-01

Background: We tested the effect of weight loss on circulating levels of the angiogenic factors VEGF and pigment epithelium-derived factor (PEDF) in postmenopausal overweight/obese women, 18 months after completing a year-long 4-arm randomized controlled trial of behavioral weight loss and/or exercise versus control (i.e., 30 months postrandomization). Methods: The 439 overweight/obese, postmenopausal women, ages 50 to 75 years, were randomized to: diet (goal: 10% weight loss, N = 118), exercise (225 min/wk moderate-to-vigorous activity, N = 117), diet + exercise ( N = 117), or control ( N = 87). At 12 months, 399 women gave a blood sample; 156 returned at 30 months. Biomarkers were measured by immunoassay. Changes were compared using generalized estimating equations, adjusting for baseline BMI, age, and race/ethnicity. Results: Participants randomized to diet, exercise, and diet + exercise arms had greater reductions in VEGF at 30 months (-14.1% P = 0.02; -19.7% P = 0.003; -14.5% P = 0.002, respectively) versus controls (-4.5%). There were no statistically significant changes in PEDF in any intervention arm. Participants maintaining ≥10% of baseline weight loss at 30 months had greater reductions in VEGF versus those who gained weight/had no weight change (-22.3% vs. -10.2% respectively, P = 0.002). Participants maintaining any weight loss had significantly lower levels of PEDF at 30 months versus those who gained weight/no weight change. Conclusions: Sustained weight loss via diet and/or exercise results in reductions in angiogenic factors, and can be maintained up to 30-month follow-up. Limitations include relatively small numbers, and possible bias toward more successful weight loss among women who returned at 30 months. Impact: Maintaining weight loss can achieve long-term reductions in biomarkers of angiogenesis that can persist up to 18 months after completion of a weight loss intervention. Cancer Epidemiol Biomarkers Prev; 26(12); 1788-94. ©2017 AACR . ©2017 American Association for Cancer Research.

Prevalence of significant weight loss and hypernatremia in breast feeding jaundice infants readmitted to Phramongkutklao Hospital within 1 month of age.

PubMed

Suksumek, Nithipun; Pirunnet, Tanin; Chamnanvanakij, Sangkae; Saengaroon, Preyapan

2010-11-01

Neonatal jaundice, especially breast feeding jaundice is the most common cause of neonatal re-admission within the first month of life. Good maternal support and closed follow-up of newborn infants can promote successful breast feeding without causing any complications. To determine the rate of significant weight loss and hypernatremia in infants with breast feeding jaundice readmitted to Phramongkutklao Hospital within 1 month of age. Cross-sectional descriptive study was conducted in infants of gestational age > or = 35 weeks and birth weight > or = 2,000 grams who had breast feeding jaundice readmitted between January, 1st and December 31st, 2008. Maternal and neonatal history, laboratory result, complications and treatment were reviewed. Rates of significant weight loss and hypernatremia were calculated. The associations between weight loss and factors, serum sodium, serum bilirubin and weight loss were analyzed using Chi-square and Mann-Whitney U test. There were 30 infants in the study. 12 (40%) were male. The median gestational age and birth weight were 37 (35-40) weeks and 2,945 (2,100-3,810) grams, respectively. Three infants had significant weight loss more than 10% of birth weights. No infant had hyperbilirubinemia. Severity of weight loss was associated with weight loss at the time before discharge from hospital. Weight loss was not associated with gestational age, sex, parity, cesarean section, exclusive breast feeding, serum sodium level, and serum bilirubin level. Complications of dehydration such as hypernatremia was not observed in infants with breast feeding jaundice in this study. Maternal education, serial weight measurements and awareness of breast-feeding jaundice problems are helpful strategies to promote successful breast feeding.

Weight change in a commercial web-based weight loss program and its association with website use: cohort study.

PubMed

Neve, Melinda; Morgan, Philip J; Collins, Clare E

2011-10-12

There is a paucity of information in the scientific literature on the effectiveness of commercial weight loss programs, including Web-based programs. The potential of Web-based weight loss programs has been acknowledged, but their ability to achieve significant weight loss has not been proven. The objectives were to evaluate the weight change achieved within a large cohort of individuals enrolled in a commercial Web-based weight loss program for 12 or 52 weeks and to describe participants' program use in relation to weight change. Participants enrolled in an Australian commercial Web-based weight loss program from August 15, 2007, through May 31, 2008. Self-reported weekly weight records were used to determine weight change after 12- and 52-week subscriptions. The primary analysis estimated weight change using generalized linear mixed models (GLMMs) for all participants who subscribed for 12 weeks and also for those who subscribed for 52 weeks. A sensitivity analysis was conducted using the last observation carried forward (LOCF) method. Website use (ie, the number of days participants logged on, made food or exercise entries to the Web-based diary, or posted to the discussion forum) was described from program enrollment to 12 and 52 weeks, and differences in website use by percentage weight change category were tested using Kruskal-Wallis test for equality of populations. Participants (n = 9599) had a mean (standard deviation [SD]) age of 35.7 (9.5) years and were predominantly female (86% or 8279/9599) and obese (61% or 5866/9599). Results from the primary GLMM analysis including all enrollees found the mean percentage weight change was -6.2% among 12-week subscribers (n = 6943) and -6.9% among 52-week subscribers (n = 2656). Sensitivity analysis using LOCF revealed an average weight change of -3.0% and -3.5% after 12 and 52 weeks respectively. The use of all website features increased significantly (P < .01) as percentage weight change improved. The weight loss achieved by 12- and 52-week subscribers of a commercial Web-based weight loss program is likely to be in the range of the primary and sensitivity analysis results. While this suggests that, on average, clinically important weight loss may be achieved, further research is required to evaluate the efficacy of this commercial Web-based weight loss program prospectively using objective measures. The potential association between greater website use and increased weight loss also requires further evaluation, as strategies to improve participants' use of Web-based program features may be required.

Unreported sauna use in anorexia nervosa: evidence from the world-wide-web.

PubMed

Vähäsoini, A; Vazquez, R; Birmingham, C L; Gutierrez, E

2004-03-01

Weight loss methods employed in anorexia nervosa (AN) are vomiting, laxatives, diuretics, enemas, suppositories, ipecac, weight loss medications and inadequate insulin in diabetics. Some methods result in weight loss from fluid depletion and not a reduction in body fat. Sauna use causes rapid fluid loss, but has not been reported in the medical literature as a weight loss strategy used in AN. We found reports of sauna use in AN on the world-wide-web are rare. We hypothesize that the warming caused by the use of sauna, may result in physical improvement in AN and thereby reduce its acceptability as a weight loss strategy.

A tabulation of pipe length to diameter ratios as a function of Mach number and pressure ratios for compressible flow

NASA Technical Reports Server (NTRS)

Dixon, G. V.; Barringer, S. R.; Gray, C. E.; Leatherman, A. D.

1975-01-01

Computer programs and resulting tabulations are presented of pipeline length-to-diameter ratios as a function of Mach number and pressure ratios for compressible flow. The tabulations are applicable to air, nitrogen, oxygen, and hydrogen for compressible isothermal flow with friction and compressible adiabatic flow with friction. Also included are equations for the determination of weight flow. The tabulations presented cover a wider range of Mach numbers for choked, adiabatic flow than available from commonly used engineering literature. Additional information presented, but which is not available from this literature, is unchoked, adiabatic flow over a wide range of Mach numbers, and choked and unchoked, isothermal flow for a wide range of Mach numbers.

Psychosocial Predictors of Weight Loss among American Indian and Alaska Native Participants in a Diabetes Prevention Translational Project

PubMed Central

Dill, Edward J.; Manson, Spero M.; Jiang, Luohua; Pratte, Katherine A.; Gutilla, Margaret J.; Knepper, Stephanie L.; Beals, Janette; Roubideaux, Yvette; Special Diabetes Program for Indians Diabetes Prevention Demonstration Project

2016-01-01

The association of psychosocial factors (psychological distress, coping skills, family support, trauma exposure, and spirituality) with initial weight and weight loss among American Indians and Alaska Natives (AI/ANs) in a diabetes prevention translational project was investigated. Participants (n = 3,135) were confirmed as prediabetic and subsequently enrolled in the Special Diabetes Program for Indians Diabetes Prevention (SDPI-DP) demonstration project implemented at 36 Indian health care programs. Measures were obtained at baseline and after completing a 16-session educational curriculum focusing on weight loss through behavioral changes. At baseline, psychological distress and negative family support were linked to greater weight, whereas cultural spirituality was correlated with lower weight. Furthermore, psychological distress and negative family support predicted less weight loss, and positive family support predicted greater weight loss, over the course of the intervention. These bivariate relationships between psychosocial factors and weight remained statistically significant within a multivariate model, after controlling for sociodemographic characteristics. Conversely, coping skills and trauma exposure were not significantly associated with baseline weight or change in weight. These findings demonstrate the influence of psychosocial factors on weight loss in AI/AN communities and have substantial implications for incorporating adjunctive intervention components. PMID:26649314

Randomized Controlled Trial Examining the Ripple Effect of a Nationally Available Weight Management Program on Untreated Spouses.

PubMed

Gorin, Amy A; Lenz, Erin M; Cornelius, Talea; Huedo-Medina, Tania; Wojtanowski, Alexis C; Foster, Gary D

2018-03-01

For married couples, when one spouse participates in weight loss treatment, the untreated spouse can also experience weight loss. This study examined this ripple effect in a nationally available weight management program. One hundred thirty dyads were randomized to Weight Watchers (WW; n = 65) or to a self-guided control group (SG; n = 65) and assessed at 0, 3, and 6 months. Inclusion criteria were age ≥ 25 years, BMI 27 to 40 kg/m 2 (≥ 25 kg/m 2 for untreated spouses), and no weight loss contraindications. WW participants received 6 months of free access to in-person meetings and online tools. SG participants received a weight loss handout. Spouses did not receive treatment. Untreated spouses lost weight at 3 months (WW = -1.5 ± 2.9 kg; SG = -1.1 ± 3.3 kg) and 6 months (WW = -2.2 ± 4.2 kg; SG = -1.9 ± 3.6 kg), but weight losses did not differ by condition. Overall, 32.0% of untreated spouses lost ≥ 3% of initial body weight by 6 months. Baseline weight was significantly correlated within couples (r = 0.26; P < 0.01) as were weight loss trajectories (r = 0.52; P < 0.001). Evidence of a ripple effect was found in untreated spouses in both formal and self-guided weight management approaches. These data suggest that weight loss can spread within couples, and that widely available lifestyle programs have weight loss effects beyond the treated individual. © 2018 The Authors. Obesity published by Wiley Periodicals, Inc. on behalf of The Obesity Society (TOS).

A weight-neutral versus weight-loss approach for health promotion in women with high BMI: A randomized-controlled trial.

PubMed

Mensinger, Janell L; Calogero, Rachel M; Stranges, Saverio; Tylka, Tracy L

2016-10-01

Weight loss is the primary recommendation for health improvement in individuals with high body mass index (BMI) despite limited evidence of long-term success. Alternatives to weight-loss approaches (such as Health At Every Size - a weight-neutral approach) have been met with their own concerns and require further empirical testing. This study compared the effectiveness of a weight-neutral versus a weight-loss program for health promotion. Eighty women, aged 30-45 years, with high body mass index (BMI ≥ 30 kg/m(2)) were randomized to 6 months of facilitator-guided weekly group meetings using structured manuals that emphasized either a weight-loss or weight-neutral approach to health. Health measurements occurred at baseline, post-intervention, and 24-months post-randomization. Measurements included blood pressure, lipid panels, blood glucose, BMI, weight, waist circumference, hip circumference, distress, self-esteem, quality of life, dietary risk, fruit and vegetable intake, intuitive eating, and physical activity. Intention-to-treat analyses were performed using linear mixed-effects models to examine group-by-time interaction effects and between and within-group differences. Group-by-time interactions were found for LDL cholesterol, intuitive eating, BMI, weight, and dietary risk. At post-intervention, the weight-neutral program had larger reductions in LDL cholesterol and greater improvements in intuitive eating; the weight-loss program had larger reductions in BMI, weight, and larger (albeit temporary) decreases in dietary risk. Significant positive changes were observed overall between baseline and 24-month follow-up for waist-to-hip ratio, total cholesterol, physical activity, fruit and vegetable intake, self-esteem, and quality of life. These findings highlight that numerous health benefits, even in the absence of weight loss, are achievable and sustainable in the long term using a weight-neutral approach. The trial positions weight-neutral programs as a viable health promotion alternative to weight-loss programs for women of high weight. Copyright © 2016 Elsevier Ltd. All rights reserved.

Can early weight loss, eating behaviors and socioeconomic factors predict successful weight loss at 12- and 24-months in adolescents with obesity and insulin resistance participating in a randomised controlled trial?

PubMed

Gow, Megan L; Baur, Louise A; Ho, Mandy; Chisholm, Kerryn; Noakes, Manny; Cowell, Chris T; Garnett, Sarah P

2016-04-01

Lifestyle interventions in adolescents with obesity can result in weight loss following active intervention but individual responses vary widely. This study aimed to identify predictors of weight loss at 12- and 24-months in adolescents with obesity and clinical features of insulin resistance. Adolescents (n = 111, 66 girls, aged 10-17 years) were participants in a randomised controlled trial, the RESIST study, examining the effects of two diets differing in macronutrient content on insulin sensitivity. Eighty-five completed the 12-month program and 24-month follow-up data were available for 42 adolescents. Change in weight was determined by BMI expressed as a percentage of the 95th percentile (BMI95). The study physician collected socioeconomic data at baseline. Physical activity and screen time, and psychological dimensions of eating behavior were self-reported using the validated CLASS and EPI-C questionnaires, respectively. Stepwise multiple regressions were conducted to identify models that best predicted change in BMI95 at 12- and 24-months. Mean BMI95 was reduced at 12-months compared with baseline (mean difference [MD] ± SE: -6.9 ± 1.0, P < 0.001) but adolescents had significant re-gain from 12- to 24-months (MD ± SE: 3.7 ± 1.5, P = 0.017). Participants who achieved greater 12-month weight loss had: greater 3-month weight loss, a father with a higher education, lower baseline external eating and parental pressure to eat scores and two parents living at home. Participants who achieved greater 24-month weight loss had: greater 12-month weight loss and a lower baseline emotional eating score. Early weight loss is consistently identified as a strong predictor of long-term weight loss. This could be because early weight loss identifies those more motivated and engaged individuals. Patients who have baseline factors predictive of long-term weight loss failure may benefit from additional support during the intervention. Additionally, if a patient does not achieve early weight loss, further support or transition to an alternate intervention where they may have increased success may be considered. Australian New Zealand Clinical Trial Registration Number (ACTRN) 12608000416392 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=83071.

The Role of Resistance Exercise in Weight Loss.

ERIC Educational Resources Information Center

Alexander, Jeffrey L.

2002-01-01

Explains the role of weight training in weight loss, noting how weight training contributes to the creation of a negative energy balance and explaining how resistance exercise can cause an increase in fat oxidation, both acutely and chronically. Resistance exercise has an indirect impact on weight and fat loss through increasing resting metabolic…

Comparison of weight loss by weight classification in a commercial, community-based weight loss program

USDA-ARS?s Scientific Manuscript database

The objective of our study was to determine the impact of grade of obesity on weight-loss outcomes of a community-based, intensive behavioral counseling program (Weight Watchers Points-Plus). Previous studies have shown that individuals with a higher body mass index (BMI) at the beginning of treatme...

Reduced Reward-driven Eating Accounts for the Impact of a Mindfulness-Based Diet and Exercise Intervention on Weight Loss: Data from the SHINE Randomized Controlled Trial

PubMed Central

Mason, Ashley E.; Epel, Elissa S.; Aschbacher, Kirstin; Lustig, Robert H.; Acree, Michael; Kristeller, Jean; Cohn, Michael; Dallman, Mary; Moran, Patricia J.; Bacchetti, Peter; Laraia, Barbara; Hecht, Frederick M.; Daubenmier, Jennifer

2016-01-01

Many individuals with obesity report overeating despite intentions to maintain or lose weight. Two barriers to long-term weight loss are reward-driven eating, which is characterized by a lack of control over eating, a preoccupation with food, and a lack of satiety; and psychological stress. Mindfulness training may address these barriers by promoting awareness of hunger and satiety cues, self-regulatory control, and stress reduction. We examined these two barriers as potential mediators of weight loss in the Supporting Health by Integrating Nutrition and Exercise (SHINE) randomized controlled trial, which compared the effects of a 5.5-month diet and exercise intervention with or without mindfulness training on weight loss among adults with obesity. Intention-to-treat multiple mediation models tested whether post-intervention reward-driven eating and psychological stress mediated the impact of intervention arm on weight loss at 12-and 18-months post-baseline among 194 adults with obesity (BMI: 30–45). Mindfulness (relative to control) participants had significant reductions in reward-driven eating at 6 months (post-intervention), which, in turn, predicted weight loss at 12 months. Post-intervention reward-driven eating mediated 47.1% of the total intervention arm effect on weight loss at 12 months [β=-0.06, SE(β)=0.03, p=.030, 95% CI (−0.12, −0.01)]. This mediated effect was reduced when predicting weight loss at 18 months (p=.396), accounting for 23.0% of the total intervention effect, despite similar weight loss at 12 months. Psychological stress did not mediate the effect of intervention arm on weight loss at 12 or 18 months. In conclusion, reducing reward-driven eating, which can be achieved using a diet and exercise intervention that includes mindfulness training, may promote weight loss (clinicaltrials.gov registration: NCT00960414). PMID:26867697

Reduced reward-driven eating accounts for the impact of a mindfulness-based diet and exercise intervention on weight loss: Data from the SHINE randomized controlled trial.

PubMed

Mason, Ashley E; Epel, Elissa S; Aschbacher, Kirstin; Lustig, Robert H; Acree, Michael; Kristeller, Jean; Cohn, Michael; Dallman, Mary; Moran, Patricia J; Bacchetti, Peter; Laraia, Barbara; Hecht, Frederick M; Daubenmier, Jennifer

2016-05-01

Many individuals with obesity report over eating despite intentions to maintain or lose weight. Two barriers to long-term weight loss are reward-driven eating, which is characterized by a lack of control over eating, a preoccupation with food, and a lack of satiety; and psychological stress. Mindfulness training may address these barriers by promoting awareness of hunger and satiety cues, self-regulatory control, and stress reduction. We examined these two barriers as potential mediators of weight loss in the Supporting Health by Integrating Nutrition and Exercise (SHINE) randomized controlled trial, which compared the effects of a 5.5-month diet and exercise intervention with or without mindfulness training on weight loss among adults with obesity. Intention-to-treat multiple mediation models tested whether post-intervention reward-driven eating and psychological stress mediated the impact of intervention arm on weight loss at 12- and 18-months post-baseline among 194 adults with obesity (BMI: 30-45). Mindfulness (relative to control) participants had significant reductions in reward-driven eating at 6 months (post-intervention), which, in turn, predicted weight loss at 12 months. Post-intervention reward-driven eating mediated 47.1% of the total intervention arm effect on weight loss at 12 months [β = -0.06, SE(β) = 0.03, p = .030, 95% CI (-0.12, -0.01)]. This mediated effect was reduced when predicting weight loss at 18 months (p = .396), accounting for 23.0% of the total intervention effect, despite similar weight loss at 12 months. Psychological stress did not mediate the effect of intervention arm on weight loss at 12 or 18 months. In conclusion, reducing reward-driven eating, which can be achieved using a diet and exercise intervention that includes mindfulness training, may promote weight loss (clinicaltrials.gov registration: NCT00960414). Published by Elsevier Ltd.

Relationship of cravings with weight loss and hunger. Results from a 6 month worksite weight loss intervention.

PubMed

Batra, Payal; Das, Sai Krupa; Salinardi, Taylor; Robinson, Lisa; Saltzman, Edward; Scott, Tammy; Pittas, Anastassios G; Roberts, Susan B

2013-10-01

We examined the association of food cravings with weight loss and eating behaviors in a lifestyle intervention for weight loss in worksites. This research was part of a randomized controlled trial of a 6-month weight loss intervention versus a wait-listed control in 4 Massachusetts worksites. The intervention emphasized reducing energy intake by adherence to portion-controlled menu suggestions, and assessments were obtained in 95 participants at baseline and 6 months including non-fasting body weight, food cravings (Craving Inventory and Food Craving Questionnaire for state and trait) and the eating behavior constructs restraint, disinhibition and hunger (Eating Inventory). There were statistically significant reductions in all craving variables in the intervention group compared to the controls. Within the intervention group, changes in craving-trait were significantly associated with weight loss after controlling for baseline weight, age, gender and worksite. However, in a multivariate model with craving-trait and eating behaviors (restraint, disinhibition and hunger), hunger was the only significant predictor of weight change. In contrast to some previous reports of increased food cravings with weight loss in lifestyle interventions, this study observed a broad reduction in cravings associated with weight loss. In addition, greater reductions in craving-trait were associated with greater weight change, but craving-trait was not a significant independent correlate of weight change when hunger was included in statistical models. Studies are needed to examine the effectiveness of hunger suppressing versus craving-suppressing strategies in lifestyle interventions for obesity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Brain function predictors and outcome of weight loss and weight loss maintenance.

PubMed

Szabo-Reed, Amanda N; Breslin, Florence J; Lynch, Anthony M; Patrician, Trisha M; Martin, Laura E; Lepping, Rebecca J; Powell, Joshua N; Yeh, Hung-Wen Henry; Befort, Christie A; Sullivan, Debra; Gibson, Cheryl; Washburn, Richard; Donnelly, Joseph E; Savage, Cary R

2015-01-01

Obesity rates are associated with public health consequences and rising health care costs. Weight loss interventions, while effective, do not work for everyone, and weight regain is a significant problem. Eating behavior is influenced by a convergence of processes in the brain, including homeostatic factors and motivational processing that are important contributors to overeating. Initial neuroimaging studies have identified brain regions that respond differently to visual food cues in obese and healthy weight individuals that are positively correlated with reports of hunger in obese participants. While these findings provide mechanisms of overeating, many important questions remain. It is not known whether brain activation patterns change after weight loss, or if they change differentially based on amount of weight lost. Also, little is understood regarding biological processes that contribute to long-term weight maintenance. This study will use neuroimaging in participants while viewing food and non-food images. Functional Magnetic Resonance Imaging will take place before and after completion of a twelve-week weight loss intervention. Obese participants will be followed though a 6-month maintenance period. The study will address three aims: 1. Characterize brain activation underlying food motivation and impulsive behaviors in obese individuals. 2. Identify brain activation changes and predictors of weight loss. 3. Identify brain activation predictors of weight loss maintenance. Findings from this study will have implications for understanding mechanisms of obesity, weight loss, and weight maintenance. Results will be significant to public health and could lead to a better understanding of how differences in brain activation relate to obesity. Copyright © 2014 Elsevier Inc. All rights reserved.

Brain function predictors and outcome of weight loss and weight loss maintenance

PubMed Central

Szabo-Reed, Amanda N.; Breslin, Florence J.; Lynch, Anthony M.; Patrician, Trisha M.; Martin, Laura E.; Lepping, Rebecca J.; Powell, Joshua N.; Yeh, Hung-Wen (Henry); Befort, Christie A.; Sullivan, Debra; Gibson, Cheryl; Washburn, Richard; Donnelly, Joseph E.; Savage, Cary R.

2015-01-01

Obesity rates are associated with public health consequences and rising health care costs. Weight loss interventions, while effective, do not work for everyone, and weight regain is a significant problem. Eating behavior is influenced by a convergence of processes in the brain, including homeostatic factors and motivational processing that are important contributors to overeating. Initial neuroimaging studies have identified brain regions that respond differently to visual food cues in obese and healthy weight individuals that are positively correlated with reports of hunger in obese participants. While these findings provide mechanisms of overeating, many important questions remain. It is not known whether brain activation patterns change after weight loss, or if they change differentially based on amount of weight lost. Also, little is understood regarding biological processes that contribute to long-term weight maintenance. This study will use neuroimaging in participants while viewing food and non-food images. Functional Magnetic Resonance Imaging will take place before and after completion of a twelve-week weight loss intervention. Obese participants will be followed though a 6-month maintenance period. The study will address three aims: 1. Characterize brain activation underlying food motivation and impulsive behaviors in obese individuals. 2. Identify brain activation changes and predictors of weight loss. 3. Identify brain activation predictors of weight loss maintenance. Findings from this study will have implications for understanding mechanisms of obesity, weight loss, and weight maintenance. Results will be significant to public health and could lead to a better understanding of how differences in brain activation relate to obesity. PMID:25533729

Cognitive and Self-regulatory Mechanisms of Obesity Study (COSMOS): Study protocol for a randomized controlled weight loss trial examining change in biomarkers, cognition, and self-regulation across two behavioral treatments.

PubMed

Hawkins, M A W; Colaizzi, Janna; Gunstad, John; Hughes, Joel W; Mullins, Larry L; Betts, Nancy; Smith, Caitlin E; Keirns, Natalie G; Vohs, Kathleen D; Moore, Shirley M; Forman, Evan M; Lovallo, William R

2018-03-01

Obesity is a global epidemic, yet successful interventions are rare. Up to 60% of people fail to achieve clinically meaningful, short-term weight loss (5-10% of start weight), whereas up to 72% are unsuccessful at achieving long-term weight loss (5-10% loss for ≥5years). Understanding how biological, cognitive, and self-regulatory factors work together to promote or to impede weight loss is clearly needed to optimize obesity treatment. This paper describes the methodology of the Cognitive and Self-regulatory Mechanisms of Obesity Study (the COSMOS trial). COSMOS is the first randomized controlled trial to investigate how changes in multiple biopsychosocial and cognitive factors relate to weight loss and one another across two weight loss treatments. The specific aims are to: 1) Confirm that baseline obesity-related physiological dysregulation is linked to cognitive deficits and poorer self-regulation, 2) Evaluate pre- to post-treatment change across time to assess individual differences in biomarkers, cognition, and self-regulation, and 3) Evaluate whether the acceptance-based treatment (ABT) group has greater improvements in outcomes (e.g., greater weight loss and less weight regain, improvements in biomarkers, cognition, and self-regulation), than the standard behavioral treatment group (SBT) from pre- to post-treatment and 1-year follow-up. The results of COSMOS will provide critical information about how dysregulation in biomarkers, cognition, and/or self-regulation is related to weight loss and whether weight loss treatments are differentially associated with these factors. This information will be used to identify promising treatment targets that are informed by biological, cognitive, and self-regulatory factors in order to advance obesity treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of two self-directed weight loss interventions: Limited weekly support vs. no outside support.

PubMed

Smith, Bryan K; Van Walleghen, Emily L; Cook-Wiens, Galen; Martin, Rachael N; Curry, Chelsea R; Sullivan, Debra K; Gibson, Cheryl A; Donnelly, Joseph E

2009-08-01

The purpose of this study was to compare the efficacy of two home-based weight loss interventions that differ only in the amount of outside support provided. This was a 12-week, randomized, controlled trial. One group received limited support (LWS, n = 35) via a single 10 min phone call each week while another group received no weekly support (NWS, n = 28). Both the LWS and NWS received pre-packaged meals (PM) and shakes. A third group served as control (CON, n = 30) and received no components of the intervention. Weight loss at 12 weeks was the primary outcome. Diet (PM, shake, and fruit/vegetable (F/V) intake) and physical activity (PA) were self-monitored, recorded daily and reported weekly. An exit survey was completed by participants in the intervention groups upon completion of the study. Weight loss and percent weight loss in the LWS, NWS, and CON groups were 7.7 ± 4.4 kg (8.5 ± 4.2%), 5.9 ± 4.1 kg (6.0 ± 4.2%), and 0.3 ± 1.9 kg (0.4 ± 1.2%), respectively. The decrease in body weight and percent weight loss was significantly greater in the LWS and NWS groups when compared to the CON group and the percent weight loss was significantly greater in the LWS when compared to both the NWS and CON groups. A home-based weight loss program utilizing PM and shakes results in clinically significant percent weight loss and the addition of a brief weekly call promotes additional percent weight loss. © 2009 Asian Oceanian Association for the Study of Obesity . Published by Elsevier Ltd. All rights reserved.

HNF1A variant, energy-reduced diets and insulin resistance improvement during weight loss: The POUNDS Lost trial and DIRECT.

PubMed

Huang, Tao; Wang, Tiange; Heianza, Yoriko; Sun, Dianjianyi; Ivey, Kerry; Durst, Ronen; Schwarzfuchs, Dan; Stampfer, Meir J; Bray, George A; Sacks, Frank M; Shai, Iris; Qi, Lu

2018-06-01

To determine whether weight-loss diets varying in macronutrients modulate the genetic effect of hepatocyte nuclear factor 1α (HNF1A) rs7957197 on weight loss and improvement of insulin resistance. We analysed the interaction between HNF1A rs7957197 and weight-loss diets with regard to weight loss and insulin resistance improvement among 722 overweight/obese adults from a 2-year randomized weight-loss trial, the POUNDS Lost trial. The findings were replicated in another independent 2-year weight-loss trial, the Dietary Intervention Randomized Controlled Trial (DIRECT), in 280 overweight/obese adults. In the POUNDS Lost trial, we found that a high-fat diet significantly modified the genetic effect of HNF1A on weight loss and reduction in waist circumference (P for interaction = .006 and .005, respectively). Borderline significant interactions for fasting insulin and insulin resistance (P for interaction = .07 and .06, respectively) were observed. We replicated the results in DIRECT. Pooled results showed similar significant interactions with weight loss, waist circumference reduction, and improvement in fasting insulin and insulin resistance (P values for interaction = .001, .005, .02 and .03, respectively). Greater decreases in weight, waist circumference, fasting insulin level and insulin resistance were observed in participants with the T allele compared to those without the T allele in the high-fat diet group (P = .04, .03 and .01, respectively). Our replicable findings provide strong evidence that individuals with the HNF1A rs7957197 T allele might obtain more benefits in weight loss and improvement of insulin resistance by choosing a hypocaloric and high-fat diet. © 2018 John Wiley & Sons Ltd.

Effect of rapid weight loss on performance in combat sport male athletes: does adaptation to chronic weight cycling play a role?

PubMed

Mendes, Sandro H; Tritto, Aline C; Guilherme, João Paulo L F; Solis, Marina Y; Vieira, Douglas E; Franchini, Emerson; Lancha, Antonio H; Artioli, Guilherme G

2013-12-01

Studies failing to show a negative effect of rapid weight loss (RWL) on performance have been conducted in athletes who have been cycling weight for years. It has been suggested that chronic weight cycling could lead combat athletes to become resistant to the stresses associated with weight loss. To investigate the effects of RWL up to 5% of body mass on high-intensity intermittent performance in weight cyclers (WC) and non-weight cyclers (non-WC). Eighteen male combat athletes (WC: n=10; non-WC: n=8) reduced up to 5% of their body mass in 5 days. Body composition, high-intensity performance and plasma lactate were assessed preweight loss and postweight loss. Athletes had 4 h to re-feed and rehydrate following the weigh-in. Food intake was recorded during the weight loss and the recovery periods. Athletes significantly decreased body mass, lean body mass (most likely due to fluid loss) and fat mass following weight loss. No significant changes in performance were found from preweight loss to postweight loss in both groups. Plasma lactate was significantly elevated after exercise in both groups, but no differences were found between groups and in response to RWL. For all these variables no differences were observed between groups. Athletes from both groups ingested high amounts of energy and carbohydrates during the recovery period after the weigh-in. Chronic weight cycling does not protect athletes from the negative impact of RWL on performance. The time to recover after weigh-in and the patterns of food and fluid ingestion during this period is likely to play the major role in restoring performance to baseline levels.

Associated among endocrine, inflammatory, and bone markers, body composition and weight loss induced bone loss

USDA-ARS?s Scientific Manuscript database

Weight loss reduces co-¬morbidities of obesity but decreases bone mass. Our aims were to determine whether adequate dairy intake could prevent weight loss related bone loss and to evaluate the contribution of energy-related hormones and inflammatory markers to bone metabolism. Overweight and obese w...

Behaviours associated with weight loss maintenance and regaining in a Mediterranean population sample. A qualitative study.

PubMed

Karfopoulou, E; Mouliou, K; Koutras, Y; Yannakoulia, M

2013-10-01

In the US, the National Weight Control Registry revealed lifestyle behaviours shared by weight loss maintainers. In the US and the UK, qualitative studies compared the experiences of weight loss maintainers and regainers. High rates of physical activity, a low-energy/low-fat diet, weight self-monitoring, breakfast consumption and flexible control of eating are well-established maintenance behaviours. The Mediterranean lifestyle has not been studied relative to weight loss maintenance. This study focused on a sample of Greek maintainers and regainers. Maintainers emphasized home-cooked meals; their diet does not appear to be low-fat, as home-cooked Greek meals are rich in olive oil. Having a small dinner is a common strategy among maintainers. Health motives were not mentioned by maintainers. Maintainers, but not regainers, appeared to compensate for emotional eating. Weight loss maintenance is imperative to successful obesity treatment. We qualitatively explored lifestyle behaviours associated with weight regulation, in a sample of Greek volunteers who had lost weight and either maintained or regained it. A 10% intentional loss maintained for at least one year was considered successful maintenance. Volunteers (n = 44, 41% men) formed eight focus groups, four of maintainers and four of regainers. Questions regarded weight loss, weight maintenance or regaining, and beliefs on weight maintenance and regaining. All discussions were tape recorded. Maintainers lost weight on their own, whereas regainers sought professional help. Maintainers exercised during both the loss and maintenance phases, whereas regainers showed inconsistent physical activity levels. Health motives for weight loss were mentioned only by regainers. Emotional eating was a common barrier, but only maintainers compensated for it. Maintainers continuously applied specific strategies to maintain their weight: emphasizing home-cooked meals, high eating frequency, a small dinner, portion size regulation, and sweets' intake regulation. Regainers considered the behaviours leading to weight loss different from their normal lifestyle, and resumed their old habits when the diet was over. However, both groups believed that for long-term success, lifestyle changes need to be permanent. © 2013 The Authors. Clinical Obesity © 2013 International Association for the Study of Obesity.

Success of a weight loss plan for overweight dogs: The results of an international weight loss study

PubMed Central

Flanagan, John; Bissot, Thomas; Hours, Marie-Anne; Moreno, Bernabe; Feugier, Alexandre

2017-01-01

Introduction Obesity is a global concern in dogs with an increasing prevalence, and effective weight loss solutions are required that work in different geographical regions. The main objective was to conduct an international, multi-centre, weight loss trial to determine the efficacy of a dietary weight loss intervention in obese pet dogs. Methods A 3-month prospective observational cohort study of weight loss in 926 overweight dogs was conducted at 340 veterinary practices in 27 countries. Commercially available dry or wet weight loss diets were used, with the initial energy allocation being 250–335 kJ/kg target body weight0.75/day (60–80 kcal/kg target body weight0.75/day) depending on sex and neuter status. The primary outcome measure was percentage weight loss; the main secondary outcomes were changes in activity, quality of life, and food-seeking behaviour, which were subjectively determined from owner descriptions. Results At baseline, median (range) age was 74 (12 to 193) months and median body condition score was 8 (range 7–9). 896 of the 926 dogs (97%) lost weight, with mean weight loss being 11.4 ±5.84%. Sexually intact dogs lost more weight than neutered dogs (P = 0.001), whilst female dogs lost more weight than male dogs (P = 0.007), with the difference being more pronounced in North and South American dogs (median [Q1, Q3]: female: 11.5% [8.5%, 14.5%]; male: 9.1% [6.3%, 12.1%], P = 0.053) compared with those from Europe (female: 12.3% [8.9%, 14.9%]; male: 10.9% [8.6%, 15.4%]). Finally, subjective scores for activity (P<0.001) and quality of life (P<0.001) increased sequentially, whilst scores for food-seeking behaviour decreased sequentially (P<0.001) during the study. Conclusion This is the largest international multi-centre weight loss study conducted to date in obese dogs. Most dogs lost a clinically significant amount of weight, although there were notable differences between dogs of different sex, neuter status and in different geographical locations. PMID:28886096

Synthesis of polyimides from α,αʹ-bis(3-aminophenoxy)-p-xylene: Spectroscopic, single crystal XRD and thermal studies

NASA Astrophysics Data System (ADS)

Ashraf, Ahmad Raza; Akhter, Zareen; Simon, Leonardo C.; McKee, Vickie; Castel, Charles Dal

2018-05-01

The meta-catenated ether-based diamine monomer α,αʹ-bis(3-aminophenoxy)-p-xylene (3APX) was synthesized from dinitro precursor α,αʹ-bis(3-nitrophenoxy)-p-xylene (3NPX). FTIR, 1H and 13C NMR spectroscopic studies accompanied by elemental analysis were performed for structural elucidations of 3NPX and 3APX. The spatial orientations of 3APX were explored by single crystal X-ray diffraction analysis. Its crystal system was found to be monoclinic, adopting the space group P21/c. The synthesized diamine monomer (3APX) was used for preparation of new series of polyimides by reacting with three different dianhydrides (BTDA, ODPA, 6FDA). The relevant copolyimides were developed via incorporation of 4,4ʹ-methylenedianiline (MDA) in the backbone of afore-synthesized polyimides. The structures of polyimides and copolyimides were verified by FTIR and 1H NMR spectroscopic techniques. Their properties were evaluated by dynamic and isothermal TGA (nitrogen and air atmospheres) and WAXRD studies. Polyimides displayed significantly high thermal stability as their degradation started around 400 °C and it was improved further by execution of copolymerization strategy with MDA. The 5% weight loss temperature (T5) of polyimides under nitrogen atmosphere was in the range of 425-460 °C while for copolyimides it increased to 454-498 °C. Thermal decomposition in air was slower than nitrogen between 400 and 550 °C however it was accelerated above 550 °C. Isothermal TGA disclosed that copolyimides have the ability to endure elevated temperatures for extended period. WAXRD analysis showed the amorphous nature of polyimides and copolyimides.

Greater hunger and less restraint predict weight loss success with phentermine treatment

PubMed Central

Thomas, Elizabeth A.; McNair, Bryan; Bechtell, Jamie L.; Ferland, Annie; Cornier, Marc-Andre; Eckel, Robert H.

2015-01-01

Objective Phentermine is thought to cause weight loss through a reduction in hunger. We hypothesized that higher hunger ratings would predict greater weight loss with phentermine. Design and Methods This is an observational pilot study in which all subjects were treated with phentermine for 8 weeks and appetite and eating behaviors were measured at baseline and week 8. Outcomes were compared in subjects with ≥5% vs <5% weight loss, and linear regression was used to identify predictors of percent weight loss. Results 27 subjects (37 ± 4.5 yrs, 93.8 ± 12.1 kg, BMI 33.8 ± 3.1 kg/m2) completed the study, with mean weight loss of -5.4 ± 3.3 kg (-5.7 ± 3.2%). Subjects with ≥5% weight loss had higher baseline pre-breakfast hunger (p=0.017), desire to eat (p=0.003), and prospective food consumption (0.006), and lower baseline cognitive restraint (p=0.01). In addition, higher baseline home prospective food consumption (p=0.002) and lower baseline cognitive restraint (p<0.001) were found to be predictors of weight loss. Conclusion These results suggest that individuals reporting greater hunger and less restraint are more likely to achieve significant weight loss with phentermine. This information can be used clinically to determine who might benefit most from phentermine treatment. PMID:26584649

Greater hunger and less restraint predict weight loss success with phentermine treatment.

PubMed

Thomas, Elizabeth A; Mcnair, Bryan; Bechtell, Jamie L; Ferland, Annie; Cornier, Marc-Andre; Eckel, Robert H

2016-01-01

Phentermine is thought to cause weight loss through a reduction in hunger. It was hypothesized that higher hunger ratings would predict greater weight loss with phentermine. This is an observational pilot study in which all subjects were treated with phentermine for 8 weeks and appetite and eating behaviors were measured at baseline and week 8. Outcomes were compared in subjects with ≥5% vs. <5% weight loss, and linear regression was used to identify predictors of percent weight loss. Twenty-seven subjects (37 ± 4.5 years, 93.8 ± 12.1 kg, BMI 33.8 ± 3.1 kg m(-2) ) completed the study, with mean weight loss of -5.4 ± 3.3 kg (-5.7% ± 3.2%). Subjects with ≥5% weight loss had higher baseline pre-breakfast hunger (P = 0.017), desire to eat (P =0.003), and prospective food consumption (0.006) and lower baseline cognitive restraint (P = 0.01). In addition, higher baseline home prospective food consumption (P = 0.002) and lower baseline cognitive restraint (P < 0.001) were found to be predictors of weight loss. These results suggest that individuals reporting greater hunger and less restraint are more likely to achieve significant weight loss with phentermine. This information can be used clinically to determine who might benefit most from phentermine treatment. © 2015 The Obesity Society.

Obesity-induced decreases in muscle performance are not reversed by weight loss.

PubMed

Seebacher, F; Tallis, J; McShea, K; James, R S

2017-08-01

Obesity can affect muscle phenotypes, and may thereby constrain movement and energy expenditure. Weight loss is a common and intuitive intervention for obesity, but it is not known whether the effects of obesity on muscle function are reversible by weight loss. Here we tested whether obesity-induced changes in muscle metabolic and contractile phenotypes are reversible by weight loss. We used zebrafish (Danio rerio) in a factorial design to compare energy metabolism, locomotor capacity, muscle isometric force and work-loop power output, and myosin heavy chain (MHC) composition between lean fish, diet-induced obese fish, and fish that were obese and then returned to lean body mass following diet restriction. Obesity increased resting metabolic rates (P<0.001) and decreased maximal metabolic rates (P=0.030), but these changes were reversible by weight loss, and were not associated with changes in muscle citrate synthase activity. In contrast, obesity-induced decreases in locomotor performance (P=0.0034), and isolated muscle isometric stress (P=0.01), work-loop power output (P<0.001) and relaxation rates (P=0.012) were not reversed by weight loss. Similarly, obesity-induced decreases in concentrations of fast and slow MHCs, and a shift toward fast MHCs were not reversed by weight loss. Obesity-induced changes in locomotor performance and muscle contractile function were not reversible by weight loss. These results show that weight loss alone may not be a sufficient intervention.

Using Avatars to Model Weight Loss Behaviors: Participant Attitudes and Technology Development

PubMed Central

Napolitano, Melissa A.; Hayes, Sharon; Russo, Giuseppe; Muresu, Debora; Giordano, Antonio; Foster, Gary D.

2013-01-01

Background: Virtual reality and other avatar-based technologies are potential methods for demonstrating and modeling weight loss behaviors. This study examined avatar-based technology as a tool for modeling weight loss behaviors. Methods: This study consisted of two phases: (1) an online survey to obtain feedback about using avatars for modeling weight loss behaviors and (2) technology development and usability testing to create an avatar-based technology program for modeling weight loss behaviors. Results: Results of phase 1 (n = 128) revealed that interest was high, with 88.3% stating that they would participate in a program that used an avatar to help practice weight loss skills in a virtual environment. In phase 2, avatars and modules to model weight loss skills were developed. Eight women were recruited to participate in a 4-week usability test, with 100% reporting they would recommend the program and that it influenced their diet/exercise behavior. Most women (87.5%) indicated that the virtual models were helpful. After 4 weeks, average weight loss was 1.6 kg (standard deviation = 1.7). Conclusion: This investigation revealed a high level of interest in an avatar-based program, with formative work indicating promise. Given the high costs associated with in vivo exposure and practice, this study demonstrates the potential use of avatar-based technology as a tool for modeling weight loss behaviors. PMID:23911189

Effect of deacetylation on property of electrospun chitosan/PVA nanofibrous membrane and removal of methyl orange, Fe(III) and Cr(VI) ions.

PubMed

Habiba, Umma; Siddique, Tawsif A; Talebian, Sepehr; Lee, Jacky Jia Li; Salleh, Areisman; Ang, Bee Chin; Afifi, Amalina M

2017-12-01

In this study, effect of degree of deacetylation on property and adsorption capacity of chitosan/polyvinyl Alcohol electrospun membrane has been investigated. Resulting nanofibers were characterized by FESEM, FTIR, XRD, TGA, tensile testing, weight loss test and adsorption test. FESEM result shows, finer nanofiber was fabricated from 42h hydrolyzed chitosan and PVA blend solution. FTIR and XRD result showed a strong interaction between chitosan and polyvinyl alcohol. Higher tensile strength was observed for the nanofiber having 42h hydrolyzed chitosan. Blend solution of chitosan/PVA having low DD chitosan had higher viscosity. The nanofibrous membrane was stable in distilled water, acidic and basic medium. The isotherm study shows that the adsorption capacity (q m ) of nanofiber containing higher DD chitosan was higher for Cr(VI). In contrary, the membrane containing chitosan with lower DD showed the higher adsorption capacity for Fe(III) and methyl orange. Moreover, the effect of DD on removal percentage of adsorbate was dependent on the initial concentration of the adsorbate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Curcumin Derivatives as Green Corrosion Inhibitors for α-Brass in Nitric Acid Solution

NASA Astrophysics Data System (ADS)

Fouda, A. S.; Elattar, K. M.

2012-11-01

1,7- Bis-(4-hydroxy-3-methoxy-phenyl)-hepta-1,6-diene-4-arylazo-3,5-dione I-V have been investigated as corrosion inhibitors for α-brass in 2 M nitric acid solution using weight-loss and galvanostatic polarization techniques. The efficiency of the inhibitors increases with the increase in the inhibitor concentration but decreases with a rise in temperature. The conjoint effect of the curcumin derivatives and KSCN has also been studied. The apparent activation energy ( E a*) and other thermodynamic parameters for the corrosion process have also been calculated. The galvanostatic polarization data indicated that the inhibitors were of mixed-type, but the cathode is more polarized than the anode. The slopes of the cathodic and anodic Tafel lines ( b c and b a) are maintained approximately equal for various inhibitor concentrations. However, the value of the Tafel slopes increases together as inhibitor concentration increases. The adsorption of these compounds on α-brass surface has been found to obey the Frumkin's adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

New coumarin derivative as an eco-friendly inhibitor of corrosion of mild steel in Acid medium.

PubMed

Al-Amiery, Ahmed A; Al-Majedy, Yasameen K; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

2014-12-29

The anticorrosion ability of a synthesized coumarin, namely 2-(coumarin-4-yloxy)acetohydrazide (EFCI), for mild steel (MS) in 1 M hydrochloric acid solution has been studied using a weight loss method. The effect of temperature on the corrosion rate was investigated, and some thermodynamic parameters were calculated. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. The IE value reaches 94.7% at the highest used concentration of the new eco-friendly inhibitor. The adsorption of inhibitor on MS surface was found to obey a Langmuir adsorption isotherm. Scanning electron microscopy (SEM) was performed on inhibited and uninhibited mild steel samples to characterize the surface. The Density Function theory (DFT) was employed for quantum-chemical calculations such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy) and μ (dipole moment), and the obtained results were found to be consistent with the experimental findings. The synthesized inhibitor was characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopic studies.

Adding evidence-based behavioral weight loss strategies to a statewide wellness campaign: a randomized clinical trial.

PubMed

Leahey, Tricia M; Thomas, Graham; Fava, Joseph L; Subak, Leslee L; Schembri, Michael; Krupel, Katie; Kumar, Rajiv; Weinberg, Brad; Wing, Rena R

2014-07-01

We determined the efficacy and cost-effectiveness of adding an evidence-based Internet behavioral weight loss intervention alone or combined with optional group sessions to ShapeUp Rhode Island 2011 (SURI), a 3-month statewide wellness campaign. We randomized participants (n = 230; body mass index = 34.3 ±6.8 kg/m(2); 84% female) to the standard SURI program (S) or to 1 of 2 enhanced programs: SURI plus Internet behavioral program (SI) or SI plus optional group sessions (SIG). The primary outcome was weight loss at the end of the 3-month program. Weight losses differed among all 3 conditions (S: 1.1% ±0.9%; SI: 4.2% ±0.6%; SIG: 6.1% ±0.6%; Ps ≤ .04). Both SI and SIG increased the percentage of individuals who achieved a 5% weight loss (SI: 42%; SIG: 54%; S: 7%; Ps < .001). Cost per kilogram of weight loss was similar for S ($39) and SI ($35); both were lower than SIG ($114). Although weight losses were greatest at the end of SURI with optional group sessions, the addition of an Internet behavioral program was the most cost-effective method to enhance weight losses.

Treatment response to the RENEW weight loss intervention in schizophrenia: Impact of intervention setting

PubMed Central

Brown, Catana; Goetz, Jeannine; Hamera, Edna; Gajewski, Byron

2014-01-01

Background Individuals with serious mental illness have high rates of obesity and a need for specialized weight loss intervention programs. This study examines the efficacy of the RENEW weight loss intervention and examines the impact of the intervention setting on outcomes. Method 136 individuals with serious mental illness from 4 different settings were randomly assigned to receive the RENEW weight loss intervention or a control condition of treatment as usual. The RENEW intervention is a one year program that includes an intensive, maintenance and intermittent supports phase. Results The intervention group experienced a modest weight loss of 4.8 lbs at 3 months, 4.1 lbs at 6 months and a slight weight gain of 1.5 lbs at 12 months. The control group gained a total of 6.2 lbs at 12 months. However when settings were examined separately the responder sites had a weight loss of 9.4 lbs at 3 months, 10.9 lbs at 6 months and 7 lbs at 12 months. Discussion These results suggest that the settings in which individuals receive services may act as a support or hindrance toward response to weight loss interventions. The concept of the obesogenic environment deserves further examination as a factor in the success of weight loss programs. PMID:25261884

Treatment response to the RENEW weight loss intervention in schizophrenia: impact of intervention setting.

PubMed

Brown, Catana; Goetz, Jeannine; Hamera, Edna; Gajewski, Byron

2014-11-01

Individuals with serious mental illness have high rates of obesity and a need for specialized weight loss intervention programs. This study examines the efficacy of the RENEW weight loss intervention and examines the impact of the intervention setting on outcomes. 136 individuals with serious mental illness from 4 different settings were randomly assigned to receive the RENEW weight loss intervention or a control condition of treatment as usual. The RENEW intervention is a one year program that includes an intensive, maintenance and intermittent supports phase. The intervention group experienced a modest weight loss of 4.8 lbs at 3 months, 4.1 lbs at 6 months and a slight weight gain of 1.5 lbs at 12 months. The control group gained a total of 6.2 lbs at 12 months. However when settings were examined separately the responder sites had a weight loss of 9.4 lbs at 3 months, 10.9 lbs at 6 months and 7 lbs at 12 months. These results suggest that the settings in which individuals receive services may act as a support or hindrance toward response to weight loss interventions. The concept of the obesogenic environment deserves further examination as a factor in the success of weight loss programs. Copyright © 2014 Elsevier B.V. All rights reserved.

Improving Weight Loss Outcomes of Community Interventions by Incorporating Behavioral Strategies

PubMed Central

Crane, Melissa M.; Thomas, J. Graham; Kumar, Rajiv; Weinberg, Brad

2010-01-01

Objectives. We examined whether adding behavioral weight loss strategies could improve the outcomes of a community weight loss campaign. Methods. Shape Up RI is a 12-week, online, team-based program for health improvement in Rhode Island. In study 1, we randomly assigned participants to the standard Shape Up RI program or to the program plus video lessons on weight loss. In study 2, we randomly assigned participants to the standard program or to the program plus video lessons; daily self-monitoring of weight, eating, and exercise; and computer-generated feedback. Results. Adding video lessons alone (study 1) did not result in significantly improved weight loss (2.0 ±2.8 kg vs 1.4 ±2.9 kg; P = .15). However, when the video lessons were supplemented with self-monitoring and feedback (study 2), the average weight loss more than doubled (3.5 ±3.8 kg vs 1.4 ±2.7 kg; P < .01), and the proportion of individuals achieving a weight loss of 5% or more tripled (40.5% vs 13.2%; P < .01). Participants in study 2 submitted self-monitoring records on 78% of days, and adherence was significantly related to outcome. Conclusions. Adding behavioral strategies to community campaigns may improve weight loss outcomes with minimal additional cost. PMID:20966375

Intentional weight loss in older adults: useful or wasting disease generating strategy?

PubMed

Darmon, Patrice

2013-05-01

Strategies for weight management in older adults remain controversial as overweight may protect them against mortality whereas weight loss may have harmful effects by promoting sarcopenia and bone loss. It has been suggested that weight management for obese older adults should focus more on maintaining weight and improving physical function than promoting weight loss. This review aims to specify whether intentional weight loss in older adults is a useful or a wasting disease generating strategy. Recent randomized controlled studies have shown that a supervised, moderate caloric restriction coupled with regular exercise (both aerobic and resistance) in obese older adults do not increase mortality risk and may conversely reduce insulin resistance, metabolic complications, and disabilities without exacerbating lean mass and bone mineral density loss. In obese older adults, moderate weight loss may have beneficial effects on comorbidities, functional performances, and quality of life provided that regular physical activity can be associated. An individual approach considering life expectancy, chronic comorbidities, functional status, personal motivation, and social support should be preferred. More research is needed to define the circumstances in which cautious dietary restrictions are reasonably justified in older adults. In any case, in the oldest (≥80 years) as in frail individuals, it seems reasonable to abstain from recommending weight loss.

Effect of weight loss by a low-fat diet and a low-carbohydrate diet on peptide YY levels.

PubMed

Essah, P A; Levy, J R; Sistrun, S N; Kelly, S M; Nestler, J E

2010-08-01

To compare the effects of weight loss by an energy-restricted low-fat diet vs low-carbohydrate diet on serum peptide YY (PYY) levels. 8-Week prospective study of 30 obese adults (mean age: 42.8+/-2.0 years, mean body mass index 35.5+/-0.6 kg m(-2)). After 8 weeks, subjects on the low-carbohydrate diet lost substantially more weight than those on the low-fat diet (5.8 vs 0.99 kg, P<0.001). Weight loss by either diet resulted in a 9% reduction in both mean fasting serum PYY levels (baseline: 103.5+/-8.8 pg ml(-1), after weight loss: 94.1+/-6.5 pg ml(-1), P<0.01) and postprandial area under the curve (AUC) PYY (baseline: (20.5+/-1.5) x 10(3) pg h(-1) ml(-1), after weight loss: mean AUC PYY (18.8+/-1.4) x 10(3) pg h(-1) ml(-1), P<0.001). There was a trend towards lower levels of PYY with greater degrees of weight loss. Reduced PYY levels after weight loss by an energy-restricted low-fat or low-carbohydrate diet likely represents a compensatory response to maintain energy homeostasis and contributes to difficulty in weight loss during energy-restricted diets.

DietBet: A Web-Based Program that Uses Social Gaming and Financial Incentives to Promote Weight Loss

PubMed Central

Rosen, Jamie

2014-01-01

Background Web-based commercial weight loss programs are increasing in popularity. Despite their significant public health potential, there is limited research on the effectiveness of such programs. Objective The objective of our study was to examine weight losses produced by DietBet and explore whether baseline and engagement variables predict weight outcomes. Methods DietBet is a social gaming website that uses financial incentives and social influence to promote weight loss. Players bet money and join a game. All players have 4 weeks to lose 4% of their initial body weight. At enrollment, players can choose to share their participation on Facebook. During the game, players interact with one another and report their weight loss on the DietBet platform. At week 4, all players within each game who lose at least 4% of initial body weight are declared winners and split the pool of money bet at the start of the game. Official weigh-in procedures are used to verify weights at the start of the game and at the end. Results From December 2012 to July 2013, 39,387 players (84.04% female, 33,101/39,387; mean weight 87.8kg, SD 22.6kg) competed in 1934 games. The average amount bet was US $27 (SD US $22). A total of 65.63% (25,849/39,387) provided a verified weight at the end of the 4-week competition. The average intention-to-treat weight loss was 2.6% (SD 2.3%). Winners (n=17,171) won an average of US $59 (SD US $35) and lost 4.9% (SD 1.0%) of initial body weight, with 30.68% (5268/17,171) losing 5% or more of their initial weight. Betting more money at game entry, sharing on Facebook, completing more weigh-ins, and having more social interactions during the game predicted greater weight loss and greater likelihood of winning (Ps<.001). In addition, weight loss clustered within games (P<.001), suggesting that players influenced each others’ weight outcomes. Conclusions DietBet, a social gaming website, reached nearly 40,000 individuals in just 7 months and produced excellent 4-week weight loss results. Given its reach and potential public health impact, future research may consider examining whether a longer program promotes additional weight loss. PMID:25658966

“At 150 kg, you can't run” men's weight loss stories in a popular health magazine provide appropriate examples of good health practice

PubMed Central

Couch, Danielle; Han, Gil-Soo; Robinson, Priscilla; Komesaroff, Paul

2014-01-01

We explore weight loss stories from 47 men collected from the Australian edition of Men's Health magazine between January 2009 and December 2012. Our analysis uses a mixed methods approach that combines thematic analysis and descriptive statistics to examine weight loss strategies against clinical practice guidelines for the management of overweight and obesity. All the stories reported the use of physical activity for weight loss and most stories detailed dietary changes for weight loss. Our findings indicate that most of the men reportedly used some form of behavioural strategies to assist them in their behaviour change efforts. The weight loss methods used were consistent with clinical practice guidelines, with the exception of some dietary practices. As narratives may assist with behaviour change, stories like those examined in this study could prove to be very useful in promoting weight loss to men. PMID:25750780

Liraglutide 3.0 mg for weight management: weight-loss dependent and independent effects.

PubMed

Bays, Harold; Pi-Sunyer, Xavier; Hemmingsson, Joanna Uddén; Claudius, Birgitte; Jensen, Christine B; Van Gaal, Luc

2017-02-01

As an adjunct to a reduced-calorie diet and increased physical activity, treatment with liraglutide 3.0 mg for weight management provides a statistically significant and clinically meaningful weight loss of 5.7%-8.0% compared to 1.6%-2.6% with placebo. The objective of this post hoc analysis was to quantify the relative contribution of weight loss to the treatment effects of liraglutide 3.0 mg on key efficacy endpoints. The analysis utilized data from 4725 participants across three randomized, placebo-controlled, double-blind trials that evaluated the efficacy and safety of liraglutide 3.0 mg versus placebo, as an adjunct to a reduced-calorie diet and increased physical activity (ClinicalTrials.gov identifiers: NCT01272219, NCT01272232 and NCT01557166). The duration of two of the trials was 56 weeks; one trial was of 32 weeks' duration. A mediation analysis was performed, which ranked the relative contribution of weight loss to the treatment effects of liraglutide 3.0 mg on key cardiometabolic efficacy endpoints, Apnea-Hypopnea Index (AHI) and health-related quality of life (QoL). A limitation of this type of analysis is that it cannot conclusively prove a causal relationship. In individuals without type 2 diabetes mellitus (T2DM), endpoints predominantly driven by liraglutide-induced weight loss included waist circumference, diastolic blood pressure, triglycerides, high density lipoprotein cholesterol, AHI, and Impact of Weight on Quality of Life-Lite total and physical function scores. Endpoints predominantly independent of weight loss included the glycemic endpoints hemoglobin A1c and fasting plasma glucose in individuals with and without T2DM. Regardless of the degree of dependence on weight loss according to the mediation analysis, greater weight loss was associated with greater improvement in all endpoints. Treatment with liraglutide 3.0 mg contributes to improved cardiometabolic parameters, AHI and health-related QoL through both weight-loss dependent and weight-loss independent mechanisms.

Weight loss after head and neck cancer: A dynamic relationship with depressive symptoms.

PubMed

Van Liew, Julia R; Brock, Rebecca L; Christensen, Alan J; Karnell, Lucy Hynds; Pagedar, Nitin A; Funk, Gerry F

2017-02-01

Weight loss and depressive symptoms are critical head and neck cancer outcomes, yet their relation over the illness course is unclear. Associations between self-reported depressive symptoms and objective weight loss across the year after head and neck cancer diagnosis were examined using growth curve modeling techniques (n = 564). A reciprocal covariation pattern emerged-changes in depressive symptoms over time were associated with same-month changes in weight loss (t [1148] = 2.05; p = .041), and changes in weight loss were associated with same-month changes in depressive symptoms (t [556] = 2.43; p = .015). To the extent that depressive symptoms increased, patients lost incrementally more weight than was lost due to the passage of time and vice versa. Results also suggested that pain and eating-related quality of life might explain the reciprocal association between depressive symptoms and weight loss. In head and neck cancer, a transactional interplay between depressive symptoms and weight loss unfolds over time. © 2016 Wiley Periodicals, Inc. Head Neck 39: 370-379, 2017. © 2016 Wiley Periodicals, Inc.

Comparison of physician weight loss goals for obese male and female patients.

PubMed

Dutton, Gareth R; Perri, Michael G; Stine, Curtis C; Goble, Mary; Van Vessem, Nancy

2010-04-01

The aim of this study was to compare physicians' weight loss goals for obese male and female patients. This study was conducted in 2008-2009 in Florida, USA. Physicians (N=108; 79.6% primary care specialty) reviewed two hypothetical clinical scenarios that were identical with respect to health status and obesity (BMI=33 kg/m(2)) but differed in the gender of the patient. Physicians then completed a survey about the need for weight loss, intentions to provide weight loss counseling, and weight loss goals (i.e., ideal, successful, and acceptable goal weights) for each hypothetical patient. Physicians strongly agreed that both patients should lose weight and physician counseling and/or treatment referrals would be appropriate; however, physician weight loss goals for male and female patients differed. BMI values calculated from the suggested ideal, successful, and acceptable weight goals were significantly lower for female patients than male patients, 22.0 vs. 25. 2 kg/m(2); 25.4 vs. 27. 8 kg/m(2); and 27.0 vs. 29. 2 kg/m(2), respectively, P values <.001. Physicians endorsed significantly more stringent weight loss goals for obese female patients than obese male patients. Regardless of patient gender, physician goals exceeded the 5-10% losses currently recommended. Additional research is needed to better understand this gender discrepancy in physician expectations for obese patients. Copyright 2010 Elsevier Inc. All rights reserved.

Behavioral Weight Loss for the Management of Menopausal Hot Flashes: A Pilot Study

PubMed Central

Thurston, Rebecca C.; Ewing, Linda J.; Low, Carissa A.; Christie, Aimee J.; Levine, Michele D.

2014-01-01

Objective Although adiposity has been considered protective against hot flashes, newer data suggest positive relations between flashes and adiposity. No studies have been specifically designed to test whether weight loss reduces hot flashes. This pilot study aimed to evaluate the feasibility, acceptability, and initial efficacy of behavioral weight loss to reduce hot flashes. Methods Forty overweight/obese women with hot flashes (≥4/day) were randomized to a behavioral weight loss intervention or to wait list control. Hot flashes were assessed pre- and post-intervention via physiologic monitor, diary, and questionnaire. Comparisons of changes in hot flashes and anthropometrics between conditions were tested via Wilcoxon tests. Results Study retention (83%) and intervention satisfaction (93.8%) were high. Most women (74.1%) reported that hot flash reduction was a main motivator to lose weight. Women randomized to the weight loss intervention lost more weight (-8.86 kg) than did women randomized to control (+0.23 kg, p<.0001). Women randomized to weight loss also showed greater reductions in questionnaire-reported hot flashes (2-week hot flashes: −63.0) than did women in the control (−28.0, p=.03), a difference not demonstrated in other hot flash measures. Reductions in weight and hot flashes were significantly correlated (e.g., r=.47, p=.006). Conclusions This pilot study showed a behavioral weight loss program to be feasible, acceptable, and effective in producing weight loss among overweight/obese women with hot flashes. Findings indicate the importance of a larger study designed to test behavioral weight loss for hot flash reduction. Hot flash management could motivate women to engage in this health-promoting behavior. PMID:24977456

Behavioral weight loss for the management of menopausal hot flashes: a pilot study.

PubMed

Thurston, Rebecca C; Ewing, Linda J; Low, Carissa A; Christie, Aimee J; Levine, Michele D

2015-01-01

Although adiposity has been considered to be protective against hot flashes, newer data suggest positive relationships between hot flashes and adiposity. No studies have been specifically designed to test whether weight loss reduces hot flashes. This pilot study aimed to evaluate the feasibility, acceptability, and initial efficacy of behavioral weight loss in reducing hot flashes. Forty overweight or obese women with hot flashes (≥ 4 hot flashes/d) were randomized to either behavioral weight loss intervention or wait-list control. Hot flashes were assessed before and after intervention via physiologic monitoring, diary, and questionnaire. Comparisons of changes in hot flashes and anthropometrics between conditions were performed via Wilcoxon tests. Study retention (83%) and intervention satisfaction (93.8%) were high. Most women (74.1%) reported that hot flash reduction was a major motivator for losing weight. Women randomized to the weight loss intervention lost more weight (-8.86 kg) than did women randomized to control (+0.23 kg; P < 0.0001). Women randomized to weight loss also showed greater reductions in questionnaire-reported hot flashes (2-wk hot flashes, -63.0) than did women in the control group (-28.0; P = 0.03)-a difference not demonstrated in other hot flash measures. Reductions in weight and hot flashes were significantly correlated (eg, r = 0.47, P = 0.006). This pilot study shows a behavioral weight loss program that is feasible, acceptable, and effective in producing weight loss among overweight or obese women with hot flashes. Findings indicate the importance of a larger study designed to test behavioral weight loss for hot flash reduction. Hot flash management could motivate women to engage in this health-promoting behavior.

Principal component analysis of synthetic adulterants in herbal supplements advertised as weight loss drugs.

PubMed

Dastjerdi, Akram Ghasemi; Akhgari, Maryam; Kamali, Artin; Mousavi, Zahra

2018-05-01

Obesity is one of the major problems in many countries. Herbal drugs are widely used to treat obesity. Unfortunately the majority of herbal weight loss drugs are adulterated with active pharmaceutical ingredients. The purpose of the present study was to analyse herbal weight loss drugs for the general search for pharmaceuticals. sixty one herbal weight loss drugs that were collected from herb shops and internet in Kermanshah, Iran were analysed qualitatively using gas chromatography/mass spectrometry. Of the 61 weight loss products sampled, 72% were found to be adulterated with tramadol, caffeine, fluoxetine, rizatriptan, venlafaxine and methadone. Herbal weight loss products were adulterated with controlled and legitimate drugs. Patients should be aware of the danger of using adulterated supplements. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dietary habits and weight maintenance success in high versus low exercisers in the National Weight Control Registry

PubMed Central

Ogden, Lorraine G.; Phelan, Suzanne; Thomas, J. Graham; Hill, James O; Wing, Rena R.; Wyatt, Holly R.

2015-01-01

Background The National Weight Control Registry (NWCR) was established to examine characteristics of successful weight loss maintainers. This study compares the diet and behavioral characteristics and weight regain trajectories of NWCR members with differing physical activity (PA) levels at baseline. Methods Participants (n=3591) were divided into 4 levels of self-reported PA at registry entry (<1000, 1000 to <2250, 2250 to <3500, and ≥3500 kcals/week). We compared self-reported energy intake (EI), macronutrient composition, eating behaviors (dietary restraint, hunger, and disinhibition), weight loss maintenance strategies, and 3 year weight regain between these 4 activity groups. Results Those with the highest PA at registry entry had lost the most weight, and reported lower fat intake, more dietary restraint, and greater reliance on several specific dietary strategies to maintain weight loss. Those in the lowest PA category maintained weight loss despite low levels of PA and without greater reliance on dietary strategies. There were no differences in odds of weight regain at year 3 between PA groups. Conclusions These findings suggest that there is not a “one size fits all strategy” for successful weight loss maintenance and that weight loss maintenance may require the use of more strategies by some individuals than others. PMID:24385447

A Different Weight Loss Experience: A Qualitative Study Exploring the Behavioral, Physical, and Psychosocial Changes Associated with Yoga That Promote Weight Loss

PubMed Central

Brooks, A.; Touchton-Leonard, K.

2016-01-01

Yoga interventions improve obesity-related outcomes including body mass index (BMI), body weight, body fat, and waist circumference, yet it is unclear whether these improvements are due to increased physical activity, increased lean muscle mass, and/or changes in eating behaviors. The purpose of this study is to expand our understanding of the experience of losing weight through yoga. Methods. Semistructured interviews were qualitatively analyzed using a descriptive phenomenological approach. Results. Two distinct groups who had lost weight through yoga responded: those who were overweight and had repeatedly struggled in their attempts to lose weight (55%, n = 11) and those who were of normal weight and had lost weight unintentionally (45%, n = 9). Five themes emerged that differed slightly by group: shift toward healthy eating, impact of the yoga community/yoga culture, physical changes, psychological changes, and the belief that the yoga weight loss experience was different than past weight loss experiences. Conclusions. These findings imply that yoga could offer diverse behavioral, physical, and psychosocial effects that may make it a useful tool for weight loss. Role modeling and social support provided by the yoga community may contribute to weight loss, particularly for individuals struggling to lose weight. PMID:27594890

A Different Weight Loss Experience: A Qualitative Study Exploring the Behavioral, Physical, and Psychosocial Changes Associated with Yoga That Promote Weight Loss.

PubMed

Ross, A; Brooks, A; Touchton-Leonard, K; Wallen, G

2016-01-01

Yoga interventions improve obesity-related outcomes including body mass index (BMI), body weight, body fat, and waist circumference, yet it is unclear whether these improvements are due to increased physical activity, increased lean muscle mass, and/or changes in eating behaviors. The purpose of this study is to expand our understanding of the experience of losing weight through yoga. Methods. Semistructured interviews were qualitatively analyzed using a descriptive phenomenological approach. Results. Two distinct groups who had lost weight through yoga responded: those who were overweight and had repeatedly struggled in their attempts to lose weight (55%, n = 11) and those who were of normal weight and had lost weight unintentionally (45%, n = 9). Five themes emerged that differed slightly by group: shift toward healthy eating, impact of the yoga community/yoga culture, physical changes, psychological changes, and the belief that the yoga weight loss experience was different than past weight loss experiences. Conclusions. These findings imply that yoga could offer diverse behavioral, physical, and psychosocial effects that may make it a useful tool for weight loss. Role modeling and social support provided by the yoga community may contribute to weight loss, particularly for individuals struggling to lose weight.

Intentional Weight Loss and Endometrial Cancer Risk.

PubMed

Luo, Juhua; Chlebowski, Rowan T; Hendryx, Michael; Rohan, Thomas; Wactawski-Wende, Jean; Thomson, Cynthia A; Felix, Ashley S; Chen, Chu; Barrington, Wendy; Coday, Mace; Stefanick, Marcia; LeBlanc, Erin; Margolis, Karen L

2017-04-10

Purpose Although obesity is an established endometrial cancer risk factor, information about the influence of weight loss on endometrial cancer risk in postmenopausal women is limited. Therefore, we evaluated associations among weight change by intentionality with endometrial cancer in the Women's Health Initiative (WHI) observational study. Patients and Methods Postmenopausal women (N = 36,794) ages 50 to 79 years at WHI enrollment had their body weights measured and body mass indices calculated at baseline and at year 3. Weight change during that period was categorized as follows: stable (change within ± 5%), loss (change ≥ 5%), and gain (change ≥ 5%). Weight loss intentionality was assessed via self-report at year 3; change was characterized as intentional or unintentional. During the subsequent 11.4 years (mean) of follow-up, 566 incident endometrial cancer occurrences were confirmed by medical record review. Multivariable Cox proportional hazards regression models were used to evaluate relationships (hazard ratios [HRs] and 95% CIs) between weight change and endometrial cancer incidence. Results In multivariable analyses, compared with women who had stable weight (± 5%), women with weight loss had a significantly lower endometrial cancer risk (HR, 0.71; 95% CI, 0.54 to 0.95). The association was strongest among obese women with intentional weight loss (HR, 0.44; 95% CI, 0.25 to 0.78). Weight gain (≥ 10 pounds) was associated with a higher endometrial cancer risk than was stable weight, especially among women who had never used hormones. Conclusion Intentional weight loss in postmenopausal women is associated with a lower endometrial cancer risk, especially among women with obesity. These findings should motivate programs for weight loss in obese postmenopausal women.

Intentional Weight Loss and Endometrial Cancer Risk

PubMed Central

Chlebowski, Rowan T.; Hendryx, Michael; Rohan, Thomas; Wactawski-Wende, Jean; Thomson, Cynthia A.; Felix, Ashley S.; Chen, Chu; Barrington, Wendy; Coday, Mace; Stefanick, Marcia; LeBlanc, Erin; Margolis, Karen L.

2017-01-01

Purpose Although obesity is an established endometrial cancer risk factor, information about the influence of weight loss on endometrial cancer risk in postmenopausal women is limited. Therefore, we evaluated associations among weight change by intentionality with endometrial cancer in the Women’s Health Initiative (WHI) observational study. Patients and Methods Postmenopausal women (N = 36,794) ages 50 to 79 years at WHI enrollment had their body weights measured and body mass indices calculated at baseline and at year 3. Weight change during that period was categorized as follows: stable (change within ± 5%), loss (change ≥ 5%), and gain (change ≥ 5%). Weight loss intentionality was assessed via self-report at year 3; change was characterized as intentional or unintentional. During the subsequent 11.4 years (mean) of follow-up, 566 incident endometrial cancer occurrences were confirmed by medical record review. Multivariable Cox proportional hazards regression models were used to evaluate relationships (hazard ratios [HRs] and 95% CIs) between weight change and endometrial cancer incidence. Results In multivariable analyses, compared with women who had stable weight (± 5%), women with weight loss had a significantly lower endometrial cancer risk (HR, 0.71; 95% CI, 0.54 to 0.95). The association was strongest among obese women with intentional weight loss (HR, 0.44; 95% CI, 0.25 to 0.78). Weight gain (≥ 10 pounds) was associated with a higher endometrial cancer risk than was stable weight, especially among women who had never used hormones. Conclusion Intentional weight loss in postmenopausal women is associated with a lower endometrial cancer risk, especially among women with obesity. These findings should motivate programs for weight loss in obese postmenopausal women. PMID:28165909

Expert Coaching in Weight Loss: Retrospective Analysis.

PubMed

Painter, Stefanie Lynn; Ahmed, Rezwan; Kushner, Robert F; Hill, James O; Lindquist, Richard; Brunning, Scott; Margulies, Amy

2018-03-13

Providing coaches as part of a weight management program is a common practice to increase participant engagement and weight loss success. Understanding coach and participant interactions and how these interactions impact weight loss success needs to be further explored for coaching best practices. The purpose of this study was to analyze the coach and participant interaction in a 6-month weight loss intervention administered by Retrofit, a personalized weight management and Web-based disease prevention solution. The study specifically examined the association between different methods of coach-participant interaction and weight loss and tried to understand the level of coaching impact on weight loss outcome. A retrospective analysis was performed using 1432 participants enrolled from 2011 to 2016 in the Retrofit weight loss program. Participants were males and females aged 18 years or older with a baseline body mass index of ≥25 kg/m², who also provided at least one weight measurement beyond baseline. First, a detailed analysis of different coach-participant interaction was performed using both intent-to-treat and completer populations. Next, a multiple regression analysis was performed using all measures associated with coach-participant interactions involving expert coaching sessions, live weekly expert-led Web-based classes, and electronic messaging and feedback. Finally, 3 significant predictors (P<.001) were analyzed in depth to reveal the impact on weight loss outcome. Participants in the Retrofit weight loss program lost a mean 5.14% (SE 0.14) of their baseline weight, with 44% (SE 0.01) of participants losing at least 5% of their baseline weight. Multiple regression model (R 2 =.158, P<.001) identified the following top 3 measures as significant predictors of weight loss at 6 months: expert coaching session attendance (P<.001), live weekly Web-based class attendance (P<.001), and food log feedback days per week (P<.001). Attending 80% of expert coaching sessions, attending 60% of live weekly Web-based classes, and receiving a minimum of 1 food log feedback day per week were associated with clinically significant weight loss. Participant's one-on-one expert coaching session attendance, live weekly expert-led interactive Web-based class attendance, and the number of food log feedback days per week from expert coach were significant predictors of weight loss in a 6-month intervention. ©Stefanie Lynn Painter, Rezwan Ahmed, Robert F Kushner, James O Hill, Richard Lindquist, Scott Brunning, Amy Margulies. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 13.03.2018.

Amiodarone-induced hyperthyroidism during massive weight loss following gastric bypass.

PubMed

Bourron, Olivier; Ciangura, Cécile; Bouillot, Jean-Luc; Massias, Laurent; Poitou, Christine; Oppert, Jean-Michel

2007-11-01

Gastric bypass is increasingly used in morbidly obese patients to achieve significant reduction of body weight and fat mass and concurrent improvement in co-morbidities. We report the case of a 53-year-old male patient (141 kg, BMI 50 kg/m2), successfully treated by amiodarone for supraventricular arrythmia, who underwent Roux-en-Y gastric bypass (RYGBP). 6 months after surgery, he had lost 45% of his preoperative weight (44.8% of weight loss was lean mass) and developed amiodarone-induced subclinical hyperthyroidism. We hypothesize the following sequence of events: weight loss after RYGBP, therefore fat loss, decrease in distribution volume of amiodarone inducing iodine overload and hyperthyroidism, reinforcing weight loss and particularly loss of lean mass. This report emphasizes the importance of careful monitoring of weight and body composition changes after RYGBP. In this situation, checking thyroid status is recommended, especially when there is a history of thyroid disease or potentially toxic thyroid medication.

Effect of the Health Tourism weight loss programme on body composition and health outcomes in healthy and excess-weight adults.

PubMed

Sagayama, Hiroyuki; Shizuma, Kayoko; Toguchi, Makiko; Mizuhara, Hiroji; Machida, Yukiko; Yamada, Yosuke; Ebine, Naoyuki; Higaki, Yasuki; Tanaka, Hiroaki

2018-05-01

Excess weight loss while minimising fat-free mass (FFM) loss is important for health. Travel is a particular period at risk for weight gain and for which the effects of a short-term intensive weight loss programme have not been studied. Therefore, we studied the effect of a novel, 1-week supervised health travel programme combining high volume, low-to-moderate intensity exercise and energy intake restriction on weight, body composition and health outcomes in adults. Weight was also monitored for 12 weeks after the programme. In all, thirty-six subjects (nineteen men, seventeen women) consisting of sixteen excess-weight (BMI: 27·1 (sd 1·7) kg/m2) and twenty healthy-weight (BMI: 22·3 (sd 1·8) kg/m2) individuals participated. Subjects performed 1 h of slow-paced intermittent jogging three times per d and other leisure activities, whereas consuming only provided foods without water restriction. Body mass significantly decreased from pre- to post-intervention in excess-weight and healthy-weight individuals (-3·5 (sd 1·5) and -3·5 (sd 1·3) %, respectively; P<0·001 for both), and losses were maintained at 12 weeks post-intervention in both groups (-6·3 (sd 3·8) and -1·7 (sd 4·0) %, respectively; P<0·01 for both). Fat mass also significantly decreased in both groups (excess weight: -9·2 (sd 4·6) %: healthy weight: -13·4 (sd 9·0) %; P<0·01 for both), whereas FFM was maintained. Similar improvements were observed for blood biochemistry and pressure in both groups. This short-term weight loss intervention yielded favourable outcomes in both excess- and healthy-weight adults, particularly a 3·5 % weight loss with no significant change to FFM. In addition, participants maintained weight loss for at least 12 weeks. Of multiple programme choices, the Health Tourism weight loss programme's results indicate that it is a viable option.

Self-reported body weight perception and dieting practices in community-dwelling patients with schizophrenia.

PubMed

Strassnig, Martin; Brar, Jaspreet S; Ganguli, Rohan

2005-06-15

Many patients with schizophrenia are exposed to serious health risks associated with their excess body weight. Evidence exists that even a moderate amount of weight loss may have significant health benefits. Thus, weight control in schizophrenia patients has become an important treatment goal. Although studies in the general population show that satisfaction with body weight is an important predictor for engagement in various weight loss measures, the perspective of schizophrenia patients has not been assessed. Information on self-reported weight perception, desire to lose weight as well as weight loss attempts was obtained according to methods employed in the National Health and Nutrition Examination Survey, Cycle III (NHANES III). Body weight and height were measured and body mass index (BMI) was calculated. Perception of body weight and desire to lose weight were correlated to BMI. Both obese female and male subjects (BMI30) were aware of their weight status. However, whereas overweight females (BMI>25< or =29.9) accurately perceived themselves so, males in this category had difficulties perceiving themselves overweight, and consequently neither wanted to lose weight, nor tried to lose weight. As means of weight loss, caloric restriction (diet) was most frequently employed (by more than 80% of study subjects); yet only a third of study subjects (34.4%) engaged in the recommended combination of diet and exercise to lose weight. Questionable weight loss practices were also frequently employed, especially among women. Obese patients (BMI> or =30) were generally aware of their excess body weight and wanted to lose weight. Only non-obese, yet overweight males (BMI>25< or =29.9) did not perceive themselves as overweight and consequently did not try to lose weight. Weight loss practices did not always follow established recommendations. Especially women were likely to approach weight loss with questionably appropriate and unsafe methods.

Mechanisms of Weight Regain following Weight Loss.

PubMed

Blomain, Erik Scott; Dirhan, Dara Anne; Valentino, Michael Anthony; Kim, Gilbert Won; Waldman, Scott Arthur

2013-01-01

Obesity is a world-wide pandemic and its incidence is on the rise along with associated comorbidities. Currently, there are few effective therapies to combat obesity. The use of lifestyle modification therapy, namely, improvements in diet and exercise, is preferable over bariatric surgery or pharmacotherapy due to surgical risks and issues with drug efficacy and safety. Although they are initially successful in producing weight loss, such lifestyle intervention strategies are generally unsuccessful in achieving long-term weight maintenance, with the vast majority of obese patients regaining their lost weight during followup. Recently, various compensatory mechanisms have been elucidated by which the body may oppose new weight loss, and this compensation may result in weight regain back to the obese baseline. The present review summarizes the available evidence on these compensatory mechanisms, with a focus on weight loss-induced changes in energy expenditure, neuroendocrine pathways, nutrient metabolism, and gut physiology. These findings have added a major focus to the field of antiobesity research. In addition to investigating pathways that induce weight loss, the present work also focuses on pathways that may instead prevent weight regain. Such strategies will be necessary for improving long-term weight loss maintenance and outcomes for patients who struggle with obesity.

IN-HOSPITAL WEIGHT LOSS, PRESCRIBED DIET AND FOOD ACCEPTANCE

PubMed Central

LEANDRO-MERHI, Vania Aparecida; SREBERNICH, Silvana Mariana; GONÇALVES, Gisele Mara Silva; de AQUINO, José Luiz Braga

2015-01-01

Background Weight loss and malnutrition may be caused by many factors, including type of disease and treatment. Aim The present study investigated the occurrence of in-hospital weight loss and related factors. Method This cross-sectional study investigated the following variables of 456 hospitalized patients: gender, age, disease, weight variation during hospital stay, and type and acceptance of the prescribed diet. Repeated measures analysis of variance (ANOVA) was used for comparing patients' weight in the first three days in hospital stay and determining which factors affect weight. The generalized estimating equation was used for comparing the food acceptance rates. The significance level was set at 5%. Results The most prescribed diet was the regular (28.8%) and 45.5% of the patients lost weight during their stay. Acceptance of hospital food increased from the first to the third days of stay (p=0.0022) but weight loss was still significant (p<0.0001). Age and type of prescribed diet did not affect weight loss during the study period but type of disease and gender did. Patients with neoplasms (p=0.0052) and males (p=0.0002) lost more weight. Conclusion Weight loss during hospital stay was associated only with gender and type of disease. PMID:25861060

Promotion of healthy weight-control practices in young athletes.

PubMed

2005-12-01

Children and adolescents are often involved in sports in which weight loss or weight gain is perceived as an advantage. This policy statement describes unhealthy weight-control practices that may be harmful to the health and/or performance of athletes. Healthy methods of weight loss and weight gain are discussed, and physicians are given resources and recommendations that can be used to counsel athletes, parents, coaches, and school administrators in discouraging inappropriate weight-control behaviors and encouraging healthy methods of weight gain or loss, when needed.

Describing patterns of weight changes using principal components analysis: results from the Action for Health in Diabetes (Look AHEAD) research group.

PubMed

Espeland, Mark A; Bray, George A; Neiberg, Rebecca; Rejeski, W Jack; Knowler, William C; Lang, Wei; Cheskin, Lawrence J; Williamson, Don; Lewis, C Beth; Wing, Rena

2009-10-01

To demonstrate how principal components analysis can be used to describe patterns of weight changes in response to an intensive lifestyle intervention. Principal components analysis was applied to monthly percent weight changes measured on 2,485 individuals enrolled in the lifestyle arm of the Action for Health in Diabetes (Look AHEAD) clinical trial. These individuals were 45 to 75 years of age, with type 2 diabetes and body mass indices greater than 25 kg/m(2). Associations between baseline characteristics and weight loss patterns were described using analyses of variance. Three components collectively accounted for 97.0% of total intrasubject variance: a gradually decelerating weight loss (88.8%), early versus late weight loss (6.6%), and a mid-year trough (1.6%). In agreement with previous reports, each of the baseline characteristics we examined had statistically significant relationships with weight loss patterns. As examples, males tended to have a steeper trajectory of percent weight loss and to lose weight more quickly than women. Individuals with higher hemoglobin A(1c) (glycosylated hemoglobin; HbA(1c)) tended to have a flatter trajectory of percent weight loss and to have mid-year troughs in weight loss compared to those with lower HbA(1c). Principal components analysis provided a coherent description of characteristic patterns of weight changes and is a useful vehicle for identifying their correlates and potentially for predicting weight control outcomes.

Human cardiovascular disease IBC chip-wide association with weight loss and weight regain in the look AHEAD trial.

PubMed

McCaffery, Jeanne M; Papandonatos, George D; Huggins, Gordon S; Peter, Inga; Erar, Bahar; Kahn, Steven E; Knowler, William C; Lipkin, Edward W; Kitabchi, Abbas E; Wagenknecht, Lynne E; Wing, Rena R

2013-01-01

The present study identified genetic predictors of weight change during behavioral weight loss treatment. Participants were 3,899 overweight/obese individuals with type 2 diabetes from Look AHEAD, a randomized controlled trial to determine the effects of intensive lifestyle intervention (ILI), including weight loss and physical activity, relative to diabetes support and education, on cardiovascular outcomes. Analyses focused on associations of single nucleotide polymorphisms (SNPs) on the Illumina CARe iSelect (IBC) chip (minor allele frequency >5%; n = 31,959) with weight change at year 1 and year 4, and weight regain at year 4, among individuals who lost ≥ 3% at year 1. Two novel regions of significant chip-wide association with year-1 weight loss in ILI were identified (p < 2.96E-06). ABCB11 rs484066 was associated with 1.16 kg higher weight per minor allele at year 1, whereas TNFRSF11A, or RANK, rs17069904 was associated with 1.70 kg lower weight per allele at year 1. This study, the largest to date on genetic predictors of weight loss and regain, indicates that SNPs within ABCB11, related to bile salt transfer, and TNFRSF11A, implicated in adipose tissue physiology, predict the magnitude of weight loss during behavioral intervention. These results provide new insights into potential biological mechanisms and may ultimately inform weight loss treatment. © 2013 S. Karger AG, Basel.

Social Media-Promoted Weight Loss Among an Occupational Population: Cohort Study Using a WeChat Mobile Phone App-Based Campaign.

PubMed

He, Chao; Wu, Shiyan; Zhao, Yingying; Li, Zheng; Zhang, Yanyan; Le, Jia; Wang, Lei; Wan, Siyang; Li, Changqing; Li, Yindong; Sun, Xinying

2017-10-23

Being overweight and obese are major risk factors for noncommunicable diseases such as cardiovascular diseases. The prevalence of overweight and obesity is high throughout the world and these issues are very serious in the Shunyi District in China. As mobile technologies have rapidly developed, mobile apps such as WeChat are well accepted and have the potential to improve health behaviors. This study aims to evaluate the effectiveness of a mobile app (WeChat) as an intervention on weight loss behavior. This study was conducted among an occupational population from August 2015 to February 2016 in the Shunyi District of Beijing. Before the intervention, the Shunyi District Government released an official document for weight loss to all 134 government agencies and enterprises in Shunyi District. Participants willing to use our official WeChat account were enrolled in a WeChat group and received 6 months of interventions for weight loss; those who were not willing to use the account were in a control group given routine publicity on weight loss. In total, 15,310 occupational participants including 3467 participants (22.65%) in the control group and 11,843 participants (77.35%) in the WeChat group were enrolled. Participants in the WeChat group lost more weight (mean 2.09, SD 3.43 kg) than people in the control group (mean 1.78, SD 2.96 kg), and the difference in mean weight loss between the two groups for males was significant based on the stratification of age and educational level. To control for confounding factors and to explore the effects of WeChat on weight loss, the propensity score method with a multinominal logistic regression was utilized. For males, this showed that the WeChat group (with both active and inactive subgroups) had a higher probability of maintaining weight, weight loss from 1 to 2 kg, or weight loss more than 2 kg than the control group. However, the control group had higher probability of weight loss from 0 to 1 kg. Being active in WeChat was likely to be associated with weight loss. The more active participants were in the weight loss program via WeChat, the more weight they lost. The weight loss intervention campaign based on an official WeChat account focused on an occupation-based population in Shunyi District was effective for males. The more active male participants were in using WeChat, the more weight they lost. There might be no effect or there may even be a negative effect on weight loss for females. Future research should focus on how to improve adherence to the WeChat weight loss interventions, to improve and refine the WeChat content such as developing a variety of materials to attract interest, and to protect personal privacy, especially for females. ©Chao He, Shiyan Wu, Yingying Zhao, Zheng Li, Yanyan Zhang, Jia Le, Lei Wang, Siyang Wan, Changqing Li, Yindong Li, Xinying Sun. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 23.10.2017.

Equation of State of Ammonium Nitrate

NASA Astrophysics Data System (ADS)

Robbins, David L.; Sheffield, Stephen A.; Dattelbaum, Dana M.; Velisavljevic, Nenad; Stahl, David B.

2009-12-01

Ammonium nitrate (AN) is a widely used fertilizer and mining explosive. AN is commonly used in ammonium nitrate-fuel oil (ANFO), which is a mixture of explosive-grade AN prills and fuel oil in a 94:6 ratio by weight. ANFO is a non-ideal explosive with measured detonation velocities around 4 km/s. The equation of state properties and known initiation behavior of neat AN are limited. We present the results of a series of gas gun-driven plate impact experiments on pressed neat ammonium nitrate at 1.72 g/cm3. No evidence of initiation was observed under shock loading to 22 GPa. High pressure x-ray diffraction experiments in diamond anvil cells provided insight into the high pressure phase behavior over the same pressure range (to 25 GPa), as well as a static isotherm at ambient temperature. From the isotherm and thermodynamic properties at ambient conditions, a preliminary unreacted equation of state (EOS) has been developed based on the Murnaghan isotherm and Helmholtz formalism [1], which compares favorably with the available experimental Hugoniot data on several densities of AN.

Effect of hydrophobicity of pharmaceuticals and personal care products for adsorption on activated carbon: Adsorption isotherms, kinetics and mechanism.

PubMed

Kaur, Harkirat; Bansiwal, Amit; Hippargi, Girivyankatesh; Pophali, Girish R

2017-09-11

Adsorption of three pharmaceuticals and personal care products (PPCPs), namely caffeine, ibuprofen and triclosan on commercial powdered activated carbon was examined in aqueous medium. The contaminants were chosen based on their diverse log K ow (octanol-water partition coefficient) viz. - 0.07 for caffeine, 3.97 for ibuprofen and 4.76 for triclosan to examine the role of hydrophobicity on adsorption process. The adsorbent characterisation was achieved using BET surface area, SEM, pore size distribution studies and FTIR. Influence of mass of PAC, contact time, solution pH and initial concentration on adsorption capacity of PAC was studied. Adsorption isotherms and kinetics were applied to establish the mechanism of adsorption. The kinetics followed pseudo-second order with physisorption occurring through particle diffusion. The Freundlich model fitted best among the isotherm models. The adsorption capacity increased in the order CFN < IBU < TCS which correlates with increasing hydrophobicity (log K ow ), molecular weight and decreasing water solubility, respectively. We conclude that micro-pollutant hydrophobicity contributes towards adsorption on activated carbon.

Energy loss of solar p modes due to the excitation of magnetic sausage tube waves: Importance of coupling the upper atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gascoyne, A.; Jain, R.; Hindman, B. W., E-mail: a.d.gascoyne@sheffield.ac.uk, E-mail: r.jain@sheffield.ac.uk

2014-07-10

We consider damping and absorption of solar p modes due to their energy loss to magnetic tube waves that can freely carry energy out of the acoustic cavity. The coupling of p modes and sausage tube waves is studied in a model atmosphere composed of a polytropic interior above which lies an isothermal upper atmosphere. The sausage tube waves, excited by p modes, propagate along a magnetic fibril which is assumed to be a vertically aligned, stratified, thin magnetic flux tube. The deficit of p-mode energy is quantified through the damping rate, Γ, and absorption coefficient, α. The variation ofmore » Γ and α as a function of frequency and the tube's plasma properties is studied in detail. Previous similar studies have considered only a subphotospheric layer, modeled as a polytrope that has been truncated at the photosphere. Such studies have found that the resulting energy loss by the p modes is very sensitive to the upper boundary condition, which, due to the lack of an upper atmosphere, have been imposed in a somewhat ad hoc manner. The model presented here avoids such problems by using an isothermal layer to model the overlying atmosphere (chromosphere, and, consequently, allows us to analyze the propagation of p-mode-driven sausage waves above the photosphere. In this paper, we restrict our attention to frequencies below the acoustic cut off frequency. We demonstrate the importance of coupling all waves (acoustic, magnetic) in the subsurface solar atmosphere with the overlying atmosphere in order to accurately model the interaction of solar f and p modes with sausage tube waves. In calculating the absorption and damping of p modes, we find that for low frequencies, below ≈3.5 mHz, the isothermal atmosphere, for the two-region model, behaves like a stress-free boundary condition applied at the interface (z = –z{sub 0}).« less

Energy Loss of Solar p Modes due to the Excitation of Magnetic Sausage Tube Waves: Importance of Coupling the Upper Atmosphere

NASA Astrophysics Data System (ADS)

Gascoyne, A.; Jain, R.; Hindman, B. W.

2014-07-01

We consider damping and absorption of solar p modes due to their energy loss to magnetic tube waves that can freely carry energy out of the acoustic cavity. The coupling of p modes and sausage tube waves is studied in a model atmosphere composed of a polytropic interior above which lies an isothermal upper atmosphere. The sausage tube waves, excited by p modes, propagate along a magnetic fibril which is assumed to be a vertically aligned, stratified, thin magnetic flux tube. The deficit of p-mode energy is quantified through the damping rate, Γ, and absorption coefficient, α. The variation of Γ and α as a function of frequency and the tube's plasma properties is studied in detail. Previous similar studies have considered only a subphotospheric layer, modeled as a polytrope that has been truncated at the photosphere. Such studies have found that the resulting energy loss by the p modes is very sensitive to the upper boundary condition, which, due to the lack of an upper atmosphere, have been imposed in a somewhat ad hoc manner. The model presented here avoids such problems by using an isothermal layer to model the overlying atmosphere (chromosphere, and, consequently, allows us to analyze the propagation of p-mode-driven sausage waves above the photosphere. In this paper, we restrict our attention to frequencies below the acoustic cut off frequency. We demonstrate the importance of coupling all waves (acoustic, magnetic) in the subsurface solar atmosphere with the overlying atmosphere in order to accurately model the interaction of solar f and p modes with sausage tube waves. In calculating the absorption and damping of p modes, we find that for low frequencies, below ≈3.5 mHz, the isothermal atmosphere, for the two-region model, behaves like a stress-free boundary condition applied at the interface (z = -z 0).

Performance on the Iowa gambling task is related to magnitude of weight loss and salivary cortisol in a diet-induced weight loss intervention in overweight women

USDA-ARS?s Scientific Manuscript database

The overall objective of this study was to examine the relationship between executive function, specifically decision making, and weight loss. We used the Iowa Gambling Task (IGT) to characterize decision making and compared performance on this task to weight loss in obese women (n=29) participatin...

Feasibility and indicative results from a 12-month low-energy liquid diet treatment and maintenance programme for severe obesity

PubMed Central

Lean, Michael; Brosnahan, Naomi; McLoone, Philip; McCombie, Louise; Higgs, Anna Bell; Ross, Hazel; Mackenzie, Mhairi; Grieve, Eleanor; Finer, Nick; Reckless, John; Haslam, David; Sloan, Billy; Morrison, David

2013-01-01

Background There is no established primary care solution for the rapidly increasing numbers of severely obese people with body mass index (BMI) > 40 kg/m2. Aim This programme aimed to generate weight losses of ≥15 kg at 12 months, within routine primary care. Design and setting Feasibility study in primary care. Method Patients with a BMI ≥40 kg/m2 commenced a micronutrient-replete 810–833 kcal/day low-energy liquid diet (LELD), delivered in primary care, for a planned 12 weeks or 20 kg weight loss (whichever was the sooner), with structured food reintroduction and then weight-loss maintenance, with optional orlistat to 12 months. Result Of 91 patients (74 females) entering the programme (baseline: weight 131 kg, BMI 48 kg/m2, age 46 years), 58/91(64%) completed the LELD stage, with a mean duration of 14.4 weeks (standard deviation [SD] = 6.0 weeks), and a mean weight loss of 16.9 kg (SD = 6.0 kg). Four patients commenced weight-loss maintenance omitting the food-reintroduction stage. Of the remaining 54, 37(68%) started and completed food reintroduction over a mean duration of 9.3 weeks (SD = 5.7 weeks), with a further mean weight loss of 2.1 kg (SD = 3.7 kg), before starting a long-term low-fat-diet weight-loss maintenance plan. A total of 44/91 (48%) received orlistat at some stage. At 12 months, weight was recorded for 68/91 (75%) patients, with a mean loss of 12.4 kg (SD = 11.4 kg). Of these, 30 (33% of all 91 patients starting the programme) had a documented maintained weight loss of ≥15 kg at 12 months, six (7%) had a 10–15 kg loss, and 11 (12%) had a 5–10 kg loss. The indicative cost of providing this entire programme for wider implementation would be £861 per patient entered, or £2611 per documented 15 kg loss achieved. Conclusion A care package within routine primary care for severe obesity, including LELD, food reintroduction, and weight-loss maintenance, was well accepted and achieved a 12-month-maintained weight loss of ≥15 kg for one-third of all patients entering the programme. PMID:23561690

Feasibility and indicative results from a 12-month low-energy liquid diet treatment and maintenance programme for severe obesity.

PubMed

Lean, Michael; Brosnahan, Naomi; McLoone, Philip; McCombie, Louise; Higgs, Anna Bell; Ross, Hazel; Mackenzie, Mhairi; Grieve, Eleanor; Finer, Nick; Reckless, John; Haslam, David; Sloan, Billy; Morrison, David

2013-02-01

There is no established primary care solution for the rapidly increasing numbers of severely obese people with body mass index (BMI) > 40 kg/m(2). This programme aimed to generate weight losses of ≥15 kg at 12 months, within routine primary care. Feasibility study in primary care. Patients with a BMI ≥40 kg/m(2) commenced a micronutrient-replete 810-833 kcal/day low-energy liquid diet (LELD), delivered in primary care, for a planned 12 weeks or 20 kg weight loss (whichever was the sooner), with structured food reintroduction and then weight-loss maintenance, with optional orlistat to 12 months. Of 91 patients (74 females) entering the programme (baseline: weight 131 kg, BMI 48 kg/m(2), age 46 years), 58/91(64%) completed the LELD stage, with a mean duration of 14.4 weeks (standard deviation [SD] = 6.0 weeks), and a mean weight loss of 16.9 kg (SD = 6.0 kg). Four patients commenced weight-loss maintenance omitting the food-reintroduction stage. Of the remaining 54, 37(68%) started and completed food reintroduction over a mean duration of 9.3 weeks (SD = 5.7 weeks), with a further mean weight loss of 2.1 kg (SD = 3.7 kg), before starting a long-term low-fat-diet weight-loss maintenance plan. A total of 44/91 (48%) received orlistat at some stage. At 12 months, weight was recorded for 68/91 (75%) patients, with a mean loss of 12.4 kg (SD = 11.4 kg). Of these, 30 (33% of all 91 patients starting the programme) had a documented maintained weight loss of ≥15 kg at 12 months, six (7%) had a 10-15 kg loss, and 11 (12%) had a 5-10 kg loss. The indicative cost of providing this entire programme for wider implementation would be £861 per patient entered, or £2611 per documented 15 kg loss achieved. A care package within routine primary care for severe obesity, including LELD, food reintroduction, and weight-loss maintenance, was well accepted and achieved a 12-month-maintained weight loss of ≥15 kg for one-third of all patients entering the programme.

Realistic weight perception and body size assessment in a racially diverse community sample of dieters.

PubMed

Cachelin, F M; Striegel-Moore, R H; Elder, K A

1998-01-01

Recently, a shift in obesity treatment away from emphasizing ideal weight loss goals to establishing realistic weight loss goals has been proposed; yet, what constitutes "realistic" weight loss for different populations is not clear. This study examined notions of realistic shape and weight as well as body size assessment in a large community-based sample of African-American, Asian, Hispanic, and white men and women. Participants were 1893 survey respondents who were all dieters and primarily overweight. Groups were compared on various variables of body image assessment using silhouette ratings. No significant race differences were found in silhouette ratings, nor in perceptions of realistic shape or reasonable weight loss. Realistic shape and weight ratings by both women and men were smaller than current shape and weight but larger than ideal shape and weight ratings. Compared with male dieters, female dieters considered greater weight loss to be realistic. Implications of the findings for the treatment of obesity are discussed.

Diet and Physical Activity Behaviors in Primary Care Patients with Recent Intentional Weight Loss.

PubMed

Gibbs, Bethany Barone; Tudorascu, Dana; Bryce, Cindy L; Comer, Diane; Fischer, Gary S; Hess, Rachel; Huber, Kimberly A; McTigue, Kathleen M; Simkin-Silverman, Laurey R; Conroy, Molly B

2017-01-01

Lifestyle habits of primary care patients with recent, intentional weight loss are unclear and need to be better understood to aid in translational health promotion efforts. We aimed to characterize diet and exercise habits in primary care patients with recent, intentional weight loss, comparing those with greater (≥10%) vs. lesser (5 to <10%) weight loss. This was a cross-sectional analysis of baseline data from a randomized trial comparing weight loss maintenance interventions. The study included primary care patients, 18-75 years old, with ≥5% intentional weight loss via lifestyle change in the past 2 years. Participants (74% female, 87% white) had mean age 53 (12) years, body mass index 30.4 (5.9) kg/m 2 , and recent weight loss of 11 (8)%. Dietary habits were measured by the Diet Habits Survey. Physical activity and sedentary behavior were measured by self-report and objectively by pedometer. On average, participants reported high fruits and vegetables intake (5 servings/day), and low intake of fried foods (1 serving/week), desserts (1 serving/week) and sugar-sweetened beverages (0 servings/week). Those with greater vs. lesser weight loss had higher intake of fruits and vegetables (p=0.037) and low fat foods or recipes (p=0.019). Average self-reported moderate-vigorous physical activity was 319 (281) minutes/week, with significant differences between greater (374 (328) minutes/week) vs. lesser (276 (230) minutes/week) weight loss groups (p=0.017). By pedometer, 30% had ≥7,500 steps/day; the proportion was higher in greater (43%) vs. lesser (19%) weight loss groups (p=0.005). For weight loss, clinical patients typically employ simple strategies such as 5+ fruits and vegetables per day, fried foods and desserts ≤1 per week, elimination of sugary drinks, choosing low fat foods/recipes, and physical activity 45-60 min/day.

Spectral characterization and surface complexation modeling of low molecular weight organics on hematite nanoparticles: Role of electrolytes in the binding mechanism

USDA-ARS?s Scientific Manuscript database

Given the ubiquity of organic-metal oxide interfaces in environmental and medical systems, it is incumbent to obtain mechanistic details at the molecular level from experimental procedures that mimic real systems and conditions. We report herein the adsorption pH envelopes (range 9-5) and isotherms...

The effects of weight loss on relative bone mineral density in premenopausal women.

PubMed

Hamilton, Kara C; Fisher, Gordon; Roy, Jane L; Gower, Barbara A; Hunter, Gary R

2013-03-01

This study compared BMD relative to body weight following a ∼6-month weight loss program and a 1-year weight maintenance phase in premenopausal women and determined whether African American (AA) and European-American (EA) women's BMD respond similarly during weight loss. Premenopausal women (n = 115, 34 ± 5 years) were evaluated in an overweight state (BMI between 27 and 30 kg/m(2) ), following an 800 kcal/day diet/exercise program designed to reduce BMI<25 kg/m(2) , and 1-year following weight loss. BMD relative to body weight (Z-scores) increased after weight loss, but decreased during the 1-year weight maintenance phase. All 1-year follow-up BMD Z-scores were increased (except L1) compared to baseline measurements (P < 0.05). These sites included the hip neck (+0.088, P = 0.014), total hip (+0.099, P = 0.001), L2 (+0.127, P = 0.013), L3 (+0.135, P = 0.014), and L4 (+0.199, P = 0.002). AAs had significantly higher absolute BMD at all sites (P < 0.05) compared to EAs, but no time by race interactions were evident during weight loss (except in L3). These results may indicate that weight loss is safe with regard to bone health for overweight premenopausal women. Copyright © 2013 The Obesity Society.

Meal replacement with a low-calorie diet formula in weight loss maintenance after weight loss induction with diet alone.

PubMed

Vázquez, C; Montagna, C; Alcaraz, F; Balsa, J A; Zamarrón, I; Arrieta, F; Botella-Carretero, J I

2009-10-01

Weight loss in obesity can reduce morbidity and mortality and benefits persist as long as weight loss is maintained. Weight maintenance is difficult in the long term and new strategies need to be developed to achieve this goal. We aimed to evaluate the efficacy of substituting a low-calorie diet formula for a meal in a weight loss program during the maintenance phase. Randomized paralleled clinical trial including 62 adult patients with at least a 5% weight loss with diet alone for 6 months, randomized to two groups: daily replacement of one meal with a low-calorie diet formula, or dieting alone for another 6 months (weight maintenance phase). Weight maintenance or further weight loss occurred in 83.9% of patients in the intervention group, whereas only in 58.1% in the control group (P=0.025). As a whole, patients in the intervention group lost a further 3.2+/-3.7% of initial weight compared with a 1.3+/-3.6% in the control group (P=0.030). Body fat mass diminished in both groups, with no differences between them (1.6+/-3.5 vs 1.0+/-9.3 kg, respectively, P=0.239), and the same happened with free fat mass (0.9+/-3.3 vs 0.4+/-6.7 kg, respectively, P=0.471). A multivariate logistic regression analysis (R (2)=0.114, P=0.023) retained only the intervention as a predictor of the achievement of weight maintenance with an odds ratio (95% confidence interval) of 3.756 (1.138-12.391). Substitution of a low-calorie diet formula for a meal is an effective measure for weight loss maintenance compared with dieting alone.

The WORD (Wholeness, Oneness, Righteousness, Deliverance): design of a randomized controlled trial testing the effectiveness of an evidence-based weight loss and maintenance intervention translated for a faith-based, rural, African American population using a community-based participatory approach.

PubMed

Yeary, Karen Hye-cheon Kim; Cornell, Carol E; Prewitt, Elaine; Bursac, Zoran; Tilford, J Mick; Turner, Jerome; Eddings, Kenya; Love, ShaRhonda; Whittington, Emily; Harris, Kimberly

2015-01-01

The positive effects of weight loss on obesity-related risk factors diminish unless weight loss is maintained. Yet little work has focused on the translation of evidence-based weight loss interventions with the aim of sustaining weight loss in underserved populations. Using a community-based participatory approach (CBPR) that engages the strong faith-based social infrastructure characteristic of rural African American communities is a promising way to sustain weight loss in African Americans, who bear a disproportionate burden of the obesity epidemic. Led by a collaborative community-academic partnership, The WORD aims to change dietary and physical activity behaviors to produce and maintain weight loss in rural, African American adults of faith. The WORD is a randomized controlled trial with 450 participants nested within 30 churches. All churches will receive a 16-session core weight loss intervention. Half of the churches will be randomized to receive an additional 12-session maintenance component. The WORD is a cultural adaptation of the Diabetes Prevention Program, whereby small groups will be led by trained church members. Participants will be assessed at baseline, 6, 12, and 18 months. A detailed cost-effectiveness and process evaluation will be included. The WORD aims to sustain weight loss in rural African Americans. The utilization of a CBPR approach and the engagement of the faith-based social infrastructure of African American communities will maximize the intervention's sustainability. Unique aspects of this trial include the focus on weight loss maintenance and the use of a faith-based CBPR approach in translating evidence-based obesity interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

A pilot study comparing two weight loss maintenance interventions among low-income, mid-life women.

PubMed

Samuel-Hodge, Carmen D; Johnston, Larry F; Gizlice, Ziya; Garcia, Beverly A; Lindsley, Sara C; Gold, Alison D; Braxton, Danielle F; Keyserling, Thomas C

2013-07-15

Despite high obesity prevalence rates, few low-income midlife women participate in weight loss maintenance trials. This pilot study aims to assess the effectiveness of two weight loss maintenance interventions in this under-represented population. Low-income midlife women who completed a 16-week weight loss intervention and lost  ≥ 8 lbs (3.6 kg) were eligible to enroll in one of two 12-month maintenance programs. The programs were similar in content and had the same number of total contacts, but were different in the contact modality (Phone + Face-to-Face vs. Face-to-Face Only). Two criteria were used to assess successful weight loss maintenance at 12 months: (1) retaining a loss of  ≥ 5% of body weight from the start of the weight loss phase and (2) a change in body weight of  < 3%, from the start to the end of the maintenance program. Outcome measures of changes in physiologic and psychosocial factors, and evaluations of process measures and program acceptability (measured at 12 months) are also reported. For categorical variables, likelihood ratio or Fisher's Exact (for small samples) tests were used to evaluate statistically significant relationships; for continuous variables, t-tests or their equivalents were used to assess differences between means and also to identify correlates of weight loss maintenance. Overall, during the 12-month maintenance period, 41% (24/58) of participants maintained a loss of  ≥ 5% of initial weight and 43% (25/58) had a <3% change in weight. None of the comparisons between the two maintenance programs were statistically significant. However, improvements in blood pressure and dietary behaviors remained significant at the end of the 12-month maintenance period for participants in both programs. Participant attendance and acceptability were high for both programs. The effectiveness of two pilot 12-month maintenance interventions provides support for further research in weight loss maintenance among high-risk, low-income women. ClinicalTrials.gov Identifier: NCT00288301.

Effect of feeding a weight loss food beyond a caloric restriction period on body composition and resistance to weight gain in cats.

PubMed

Floerchinger, Amanda M; Jackson, Matthew I; Jewell, Dennis E; MacLeay, Jennifer M; Hahn, Kevin A; Paetau-Robinson, Inke

2015-08-15

To determine the effect of feeding a food with coconut oil and supplemental L-carnitine, lysine, leucine, and fiber on weight loss and maintenance in cats. Prospective clinical study. 50 overweight cats. The study consisted of 2 trials. During trial 1, 30 cats were allocated to 3 groups (10 cats/group) to be fed a dry maintenance cat food to maintain body weight (group 1) or a dry test food at the same amount on a mass (group 2) or energy (group 3) basis as group 1. During trial 2, each of 20 cats was fed the test food and caloric intake was adjusted to maintain a weight loss rate of 1%/wk (weight loss phase). Next, each cat was fed the test food in an amount calculated to maintain the body weight achieved at the end of the weight loss phase (weight maintenance phase). Cats were weighed and underwent dual-energy x-ray absorptiometry monthly. Metabolomic data were determined before (baseline) and after each phase. During trial 1, cats in groups 2 and 3 lost significantly more weight than did those in group 1. During trial 2, cats lost a significant amount of body weight and fat mass but retained lean body mass during the weight loss phase and continued to lose body weight and fat mass but gained lean body mass during the weight maintenance phase. Evaluation of metabolomic data suggested that fat metabolism was improved from baseline for cats fed the test food. Results suggested that feeding overweight cats the test food caused weight loss and improvements in body condition during the weight maintenance phase, possibly because the food composition improved energy metabolism.

Treatment of Obesity: Weight Loss and Bariatric Surgery

PubMed Central

Wolfe, Bruce M.; Kvach, Elizaveta; Eckel, Robert H.

2016-01-01

This review focuses on the mechanisms underlying, and indications for, bariatric surgery in the reduction of cardiovascular disease (CVD) as well as other expected benefits of this intervention. The fundamental basis for bariatric surgery for the purpose of accomplishing weight loss is the determination that severe obesity is a disease associated with multiple adverse effects on health which can be reversed or improved by successful weight loss in patients who have been unable to sustain weight loss by non-surgical means. An explanation of possible indications for weight loss surgery as well as specific bariatric surgical procedures is presented, along with review of the safety literature of such procedures. Procedures that are less invasive or those that involve less gastrointestinal rearrangement accomplish considerably less weight loss but have substantially lower perioperative and longer-term risk. The ultimate benefit of weight reduction relates to the reduction of the co-morbidities, quality of life and all-cause mortality. With weight loss being the underlying justification for bariatric surgery in ameliorating CVD risk, current evidence-based research is discussed concerning body fat distribution, dyslipidemia, hypertension, diabetes, inflammation, obstructive sleep apnea and others. The rationale for bariatric surgery reducing CVD events is discussed and juxtaposed with impacts on all-cause mortalities. Given the improvement of established obesity-related CVD risk factors following weight loss, it is reasonable to expect a reduction of CVD events and related mortality following weight loss in populations with obesity. The quality of the current evidence is reviewed and future research opportunities and summaries are stated. PMID:27230645

Association between change in body weight after midlife and risk of hip fracture-the Singapore Chinese Health Study.

PubMed

Dai, Z; Ang, L-W; Yuan, J-M; Koh, W-P

2015-07-01

The relationship between change in body weight and risk of fractures is inconsistent in epidemiologic studies. In this cohort of middle-aged to elderly Chinese in Singapore, compared to stable weight, weight loss ≥10 % over an average of 6 years is associated with nearly 40 % increase in risk of hip fracture. Findings on the relationship between change in body weight and risk of hip fracture are inconsistent. In this study, we examined this association among middle-aged and elderly Chinese in Singapore. We used prospective data from the Singapore Chinese Health Study, a population-based cohort of 63,257 Chinese men and women aged 45-74 years at recruitment in 1993-1998. Body weight and height were self-reported at recruitment and reassessed during follow-up interview in 1999-2004. Percent in weight change was computed based on the weight difference over an average of 6 years, and categorized as loss ≥10 %, loss 5 to <10 %, loss or gain <5 % (stable weight), gain 5 to <10 %, and gain ≥10 %. Multivariable Cox proportional hazards regression model was applied with adjustment for risk factors for hip fracture and body mass index (BMI) reported at follow-up interview. About 12 % experienced weight loss ≥10 %, and another 12 % had weight gain ≥10 %. After a mean follow-up of 9.0 years, we identified 775 incident hip fractures among 42,149 eligible participants. Compared to stable weight, weight loss ≥10 % was associated with 39 % increased risk (hazard ratio 1.39; 95 % confidence interval 1.14, 1.69). Such elevated risk with weight loss ≥10 % was observed in both genders and age groups at follow-up (≤65 and >65 years) and in those with baseline BMI ≥20 kg/m(2).There was no significant association with weight gain. Our findings provide evidence that substantial weight loss is an important risk factor for osteoporotic hip fractures among the middle-aged to elderly Chinese.

The utility of monetary contingency contracts for weight loss: a systematic review and meta-analysis.

PubMed

Sykes-Muskett, Bianca J; Prestwich, Andrew; Lawton, Rebecca J; Armitage, Christopher J

2015-01-01

Financial incentives to improve health have received increasing attention, but are subject to ethical concerns. Monetary Contingency Contracts (MCCs), which require individuals to deposit money that is refunded contingent on reaching a goal, are a potential alternative strategy. This review evaluates systematically the evidence for weight loss-related MCCs. Randomised controlled trials testing the effect of weight loss-related MCCs were identified in online databases. Random-effects meta-analyses were used to calculate overall effect sizes for weight loss and participant retention. The association between MCC characteristics and weight loss/participant retention effects was calculated using meta-regression. There was a significant small-to-medium effect of MCCs on weight loss during treatment when one outlier study was removed. Group refunds, deposit not paid as lump sum, participants setting their own deposit size and additional behaviour change techniques were associated with greater weight loss during treatment. Post-treatment, there was no significant effect of MCCs on weight loss. There was a significant small-to-medium effect of MCCs on participant retention during treatment. Researcher-set deposits paid as one lump sum, refunds delivered on an all-or-nothing basis and refunds contingent on attendance at classes were associated with greater retention during treatment. Post-treatment, there was no significant effect of MCCs on participant retention. The results support the use of MCCs to promote weight loss and participant retention up to the point that the incentive is removed and identifies the conditions under which MCCs work best.

Brief report: Weight dissatisfaction, weight status, and weight loss in Mexican-American children

USDA-ARS?s Scientific Manuscript database

The study objectives were to assess the association between weight dissatisfaction, weight status, and weight loss in Mexican-American children participating in a weight management program. Participants included 265 Mexican American children recruited for a school-based weight management program. Al...

Dietary Management of Obesity: Cornerstones of Healthy Eating Patterns.

PubMed

Smethers, Alissa D; Rolls, Barbara J

2018-01-01

Several dietary patterns, both macronutrient and food based, can lead to weight loss. A key strategy for weight management that can be applied across dietary patterns is to reduce energy density. Clinical trials show that reducing energy density is effective for weight loss and weight loss maintenance. A variety of practical strategies and tools can help facilitate successful weight management by reducing energy density, providing portion control, and improving diet quality. The flexibility of energy density gives patients options to tailor and personalize their dietary pattern to reduce energy intake for sustainable weight loss. Copyright © 2017 Elsevier Inc. All rights reserved.

Weight Loss Associated With Employee Income in an Incentivized Employee Wellness Program.

PubMed

Fink, Jennifer T; Rich, Jennifer; Smith, David R; Singh, Maharaj; Sutton, Kelly; Mueller, George; Ihrke, Doug M; Skalla, Jessica L; Cisler, Ron A

2016-12-01

We examined the relationship between the type of incentivized wellness program and employee weight loss and the effects of participant income. We retrospectively examined employees who participated in one of six weight loss wellness programs, which were categorized for the present analysis: reweigh/body mass index, Coaching, and Weight Watchers/Meal Replacement. Those who participated were eligible for a $350/year insurance premium discount. Employees in the low-income category of $45K or less participated at a higher rate, however, did not lose as much weight as those participants in the higher income categories of $70K or more. We found a positive association with weight loss in two of the categories, reweigh/body mass index, and Weight Watchers/Meal Replacement programs. Wellness programs have a significant impact on employee weight loss, but this relationship may vary across the income level of participants.

Value self-confrontation as a method to aid in weight loss.

PubMed

Schwartz, S H; Inbar-Saban, N

1988-03-01

The impact on weight loss of an adaptation of the Rokeach (1973) value self-confrontation method was investigated in a field experiment. This method confronts people who have ranked their own values with information about the value priorities that discriminate between a positive and a negative reference group. A preliminary study revealed that successful weight losers differ from unsuccessful weight losers in valuing "wisdom" more than "happiness." Eighty-seven overweight adults were randomly assigned to one of three conditions: value self-confrontation, group discussion, or non-treatment control. Value self-confrontation subjects lost more weight than the other subjects over 2 months, and this weight loss persisted for an additional year. Changes in value priorities during the first 2 months suggest that weight loss was mediated by an increase in the importance attributed to wisdom relative to happiness. Implications for the theory of value-behavior relations and for practical application in weight loss programs are discussed.

A Family and Community Focused Lifestyle Program Prevents Weight Regain in Pacific Islanders: A Pilot Randomized Controlled Trial

ERIC Educational Resources Information Center

Kaholokula, Joseph Keawe'aimoku; Mau, Marjorie K.; Efird, Jimmy T.; Leake, Anne; West, Margaret; Palakiko, Donna-Marie; Yoshimura, Sheryl R.; Kekauoha, B. Puni; Rose, Charles; Gomes, Henry

2012-01-01

Preventing weight regain after the loss of excess weight is challenging for people, especially for ethnic minorities in the United States. A 6-month weight loss maintenance intervention designed for Pacific Islanders, called the PILI Lifestyle Program (PLP), was compared with a 6-month standard behavioral weight loss maintenance program (SBP) in a…

Mediating Effect of Body Image Distortion on Weight Loss Efforts in Normal-Weight and Underweight Korean Adolescent Girls

ERIC Educational Resources Information Center

Choi, Jeong-Sil; Kim, Ji-Soo

2017-01-01

Background: We explored the relationship between body mass index-for-age percentile, body image distortion, and unnecessary weight loss efforts in Korean adolescent girls who are underweight and normal weight and examined the mediating effect of body image distortion on weight loss efforts. Methods: This study used data from the 2013 Korea Youth…

Web-Based Interventions Alone or Supplemented with Peer-Led Support or Professional Email Counseling for Weight Loss and Weight Maintenance in Women from Rural Communities: Results of a Clinical Trial

PubMed Central

Pullen, Carol H.; Pozehl, Bunny; Eisenhauer, Christine; Boeckner, Linda S.

2017-01-01

Objective. This trial compared the effectiveness of a web-based only (WO) intervention with web-based supplemented by peer-led discussion (WD) or professional email counseling (WE) across 3 phases to achieve weight loss and weight maintenance in women from underserved rural communities. Methods. 301 women (BMI of 28–45 kg/m2) randomly assigned to groups participated in guided weight loss (baseline to 6 months), guided weight loss and maintenance (6 to 18 months), and self-managed weight maintenance (18 to 30 months). Results. Retention was 88.7%, 76.5%, and 71.8% at 6, 18, and 30 months, respectively. Intent-to-treat analyses demonstrated no group differences in change in weight within any phases. At 6 months, observed mean (SD) weight loss was 5.1 (6.0) kg in WO, 4.1 (5.6) kg in WD, and 6.0 (6.3) kg in WE, with 42%, 38%, and 51%, respectively, meeting ≥ 5% weight loss. These proportions dropped by a third after phase 2 with no further change during phase 3. Conclusion. Web-based interventions assisted women from rural communities in achieving 6-month weight loss, with weight regain by half at 30 months. No group differences were potentially due to the robust nature of the web-based intervention. Trial Registration. This trial is registered with ClinicalTrials.gov NCT01307644. PMID:28480078

Effect of weight loss by a low-fat diet and a low-carbohydrate diet on peptide YY levels

PubMed Central

Essah, P. A.; Levy, J. R.; Sistrun, S. N.; Kelly, S. M.; Nestler, J. E.

2010-01-01

Objective To compare the effects of weight loss by an energy-restricted low-fat diet versus low-carbohydrate diet on serum peptide YY (PYY) levels. Design 8-week prospective study of 30 obese adults (mean age: 42.8 ± 2.0 years, mean BMI 35.5 ± 0.6 kg/m2). Results After 8 weeks, subjects on the low-carbohydrate diet lost substantially more weight than those on the low-fat diet (5.8 kg vs. 0.99 kg, p<0.001). Weight loss by either diet resulted in a 9% reduction in both mean fasting serum PYY levels (baseline: 103.5 ± 8.8 pg/ml, after weight loss: 94.1 ± 6.5 pg/ml, p<0.01) and postprandial AUC PYY (baseline: (20.5 ± 1.5) × 103 pg·hr−1ml−1, after weight loss: mean AUC PYY (18.8 ± 1.4) × 103 pg·hr−1ml−1 p<0.001). There was a trend towards lower levels of PYY with greater degrees of weight loss. Conclusions Reduced PYY levels after weight loss by an energy-restricted low-fat or low-carbohydrate diet likely represents a compensatory response to maintain energy homeostasis and contributes to difficulty in weight loss during energy-restricted diets. PMID:20351741

Evaluation of early weight loss thresholds for identifying nonresponders to an intensive lifestyle intervention.

PubMed

Unick, Jessica L; Hogan, Patricia E; Neiberg, Rebecca H; Cheskin, Lawrence J; Dutton, Gareth R; Evans-Hudnall, Gina; Jeffery, Robert; Kitabchi, Abbas E; Nelson, Julie A; Pi-Sunyer, F Xavier; West, Delia Smith; Wing, Rena R

2014-07-01

Weight losses in lifestyle interventions are variable, yet prediction of long-term success is difficult. The utility of using various weight loss thresholds in the first 2 months of treatment for predicting 1-year outcomes was examined. Participants included 2327 adults with type 2 diabetes (BMI:35.8 ± 6.0) randomized to the intensive lifestyle intervention (ILI) of the Look AHEAD trial. ILI included weekly behavioral sessions designed to increase physical activity and reduce caloric intake. 1-month, 2-month, and 1-year weight changes were calculated. Participants failing to achieve a ≥2% weight loss at Month 1 were 5.6 (95% CI:4.5, 7.0) times more likely to also not achieve a ≥10% weight loss at Year 1, compared to those losing ≥2% initially. These odds were increased to 11.6 (95% CI:8.6, 15.6) when using a 3% weight loss threshold at Month 2. Only 15.2% and 8.2% of individuals failing to achieve the ≥2% and ≥3% thresholds at Months 1 and 2, respectively, go on to achieve a ≥10% weight loss at Year 1. Given the association between initial and 1-year weight loss, the first few months of treatment may be an opportune time to identify those who are unsuccessful and utilize rescue efforts. clinicaltrials.gov Identifier: NCT00017953. © 2014 The Obesity Society.

Motivation and Its Relationship to Adherence to Self-Monitoring and Weight Loss in a 16-Week Internet Behavioral Weight Loss Intervention

ERIC Educational Resources Information Center

Webber, Kelly H.; Tate, Deborah F.; Ward, Dianne S.; Bowling, J. Michael

2010-01-01

Objective: To examine changes in motivation and the relationship of motivation to adherence to self-monitoring and weight loss in a 16-week Internet behavioral weight-loss intervention. Design: Two-group randomized design. Setting: This study was conducted over the Internet. Participants: Sixty-six women, ages 22-65, with a body mass index (BMI)…

Adding Evidence-Based Behavioral Weight Loss Strategies to a Statewide Wellness Campaign: A Randomized Clinical Trial

PubMed Central

Thomas, Graham; Fava, Joseph L.; Subak, Leslee L.; Schembri, Michael; Krupel, Katie; Kumar, Rajiv; Weinberg, Brad; Wing, Rena R.

2014-01-01

Objectives. We determined the efficacy and cost-effectiveness of adding an evidence-based Internet behavioral weight loss intervention alone or combined with optional group sessions to ShapeUp Rhode Island 2011 (SURI), a 3-month statewide wellness campaign. Methods. We randomized participants (n = 230; body mass index = 34.3 ±6.8 kg/m2; 84% female) to the standard SURI program (S) or to 1 of 2 enhanced programs: SURI plus Internet behavioral program (SI) or SI plus optional group sessions (SIG). The primary outcome was weight loss at the end of the 3-month program. Results. Weight losses differed among all 3 conditions (S: 1.1% ±0.9%; SI: 4.2% ±0.6%; SIG: 6.1% ±0.6%; Ps ≤ .04). Both SI and SIG increased the percentage of individuals who achieved a 5% weight loss (SI: 42%; SIG: 54%; S: 7%; Ps < .001). Cost per kilogram of weight loss was similar for S ($39) and SI ($35); both were lower than SIG ($114). Conclusions. Although weight losses were greatest at the end of SURI with optional group sessions, the addition of an Internet behavioral program was the most cost-effective method to enhance weight losses. PMID:24832424

Predictors of weight loss in low-income mothers of young children.

PubMed

Clarke, Kristine K; Freeland-Graves, Jeanne; Klohe-Lehman, Deborah M; Bohman, Thomas M

2007-07-01

To identify predictors of weight loss in a tri-ethnic population of low-income mothers. An 8-week dietary and physical activity program was tested. Demographic data were collected at baseline; anthropometric, dietary, physical activity, and psychosocial data were measured at baseline and week 8. A convenience sample of 114 Hispanic, African-American, and white, low-income mothers with a body mass index > or = 25 (calculated as kg/m2) participated in the intervention. Weight-loss classes that incorporated nutrition, physical activity, and behavior modification were administered for 8 weeks. Anthropometry (body weight, weight loss). Analysis of variance, chi2 tests, and Spearman and Pearson correlations were used to test for associations between baseline and change data and total weight loss. Hierarchical regression was employed to assess the marginal importance of factors beyond socioeconomic influences. Correlates of weight loss included less satisfaction with appearance (r=0.24), greater percentage of energy from protein (r=-0.22), enhanced nutrition knowledge (r=-0.23), and higher scores for benefits of weight loss (r =-0.20) at baseline; and the change in healthful eating attitudes (r=-0.28) and social support (r=-0.21) at 8 weeks. The predictive models of baseline and change variables represented 11.4% and 13.8% of the variance, respectively. Weight-management programs serving low-income mothers should provide techniques to enhance social support, attitudes toward healthful eating, benefits of weight loss, and nutrition knowledge.

Genetic Predictors of ≥5% Weight Loss by Multidisciplinary Advice to Severely Obese Subjects

PubMed Central

Aller, Erik E.J.G.; Mariman, Edwin C.M.; Bouwman, Freek G.; van Baak, Marleen A.

2017-01-01

Background Weight loss success is determined by genetic factors, which may differ according to treatment strategy. Methods From a multidisciplinary obesity treatment program involving dietary advice, psychological counseling, and increased physical activity, 587 subjects (68% female; 46.1 ± 12.4 years; BMI 39.9 ± 6.3) were recruited. At baseline, a blood sample was drawn for DNA isolation. Genotypes were determined for 30 polymorphisms in 25 candidate genes. The association between genotypes and weight loss was assessed after 3 months (short-term) and after 12 months of treatment (long-term). Weight loss was categorized as ≥5% or <5% of initial weight. Results The G/G genotype of PLIN1 (rs2289487) and PLIN1 (rs2304795), the T/T genotype of PLIN1 (rs1052700), and the C/C genotype of MMP2 predicted ≥5% weight loss in the first 3 months. The C/G-G/G genotype of PPARγ (rs1801282) and the T/C genotype of TIMP4 (rs3755724) predicted ≥5% weight loss after 12 months. Subjects with the combination of PPARγ (rs1801282) C/G-G/G and TIMP4 (rs3755724) T/C lost even more weight. Conclusion Polymorphisms in genes related to regulation of fat storage and structural adaptation of the adipocytes are predictors for weight loss success with different genes being relevant for short-term and long-term weight loss success. PMID:28578327

Randomized Clinical Trial of Portion-Controlled Prepackaged Foods to Promote Weight Loss

PubMed Central

Rock, Cheryl L.; Flatt, Shirley W.; Pakiz, Bilgé; Barkai, Hava-Shoshana; Heath, Dennis D.; Krumhar, Kim C.

2017-01-01

Objective Providing portion-controlled prepackaged foods in a behavioral counseling intervention may promote more weight and fat loss than a standard self-selected diet. Methods: The primary aim was to test whether providing portion-controlled prepackaged lunch and dinner entrées within a behavioral weight loss intervention promotes greater weight loss at 12 weeks in overweight/obese adults compared to self-selected foods. Other aims were to examine effects on biological factors, fitness, and meal satisfaction. One-half of those assigned to prepackaged entrées were provided items with a higher protein level (>25% energy) as an exploratory aim. Results Participants (N=183) had a baseline weight of 95.9 (15.6) kg (mean [SD]) and BMI of 33.2 (3.5) kg/m2. Weight data at 12 weeks were available for 180 subjects. Weight loss for regular entrée, higher protein entrée and control groups was 8.6 (3.9), 7.8 (5.1), and 6.0 (4.4)%, respectively (P<0.05, intervention vs. control). Intervention participants lost more body fat than controls (5.7 [3.4] vs. 4.4 [3.3] kg, P<0.05). Conclusions A meal plan incorporating portion-controlled prepackaged entrées promotes greater weight and fat loss than a standard self-selected diet, with comparable meal satisfaction. Initial weight loss predicts long-term weight loss so these results are relevant to likelihood of longer term success. PMID:27225596

Protein Recommendations for Weight Loss in Elite Athletes: A Focus on Body Composition and Performance.

PubMed

Hector, Amy J; Phillips, Stuart M

2018-03-01

There exists a large body of scientific evidence to support protein intakes in excess of the recommended dietary allowance (RDA) (0.8 g protein/kg/day) to promote the retention of skeletal muscle and loss of adipose tissue during dietary energy restriction. Diet-induced weight loss with as low as possible ratio of skeletal muscle to fat mass loss is a situation we refer to as high-quality weight loss. We propose that high-quality weight loss is often of importance to elite athletes in order to maintain their muscle (engine) and shed unwanted fat mass, potentially improving athletic performance. Current recommendations for protein intakes during weight loss in athletes are set at 1.6-2.4 g protein/kg/day. However, the severity of the caloric deficit and type and intensity of training performed by the athlete will influence at what end of this range athletes choose to be. Other considerations regarding protein intake that may help elite athletes achieve weight loss goals include the quality of protein consumed, and the timing and distribution of protein intake throughout the day. This review highlights the scientific evidence used to support protein recommendations for high-quality weight loss and preservation of performance in athletes. Additionally, the current knowledge surrounding the use of protein supplements, branched chain amino acids (BCAA), β-hydroxy β-methylbutyrate (HMB), and other dietary supplements with weight loss claims will be discussed.

Long-term persistence of hormonal adaptations to weight loss.

PubMed

Sumithran, Priya; Prendergast, Luke A; Delbridge, Elizabeth; Purcell, Katrina; Shulkes, Arthur; Kriketos, Adamandia; Proietto, Joseph

2011-10-27

After weight loss, changes in the circulating levels of several peripheral hormones involved in the homeostatic regulation of body weight occur. Whether these changes are transient or persist over time may be important for an understanding of the reasons behind the high rate of weight regain after diet-induced weight loss. We enrolled 50 overweight or obese patients without diabetes in a 10-week weight-loss program for which a very-low-energy diet was prescribed. At baseline (before weight loss), at 10 weeks (after program completion), and at 62 weeks, we examined circulating levels of leptin, ghrelin, peptide YY, gastric inhibitory polypeptide, glucagon-like peptide 1, amylin, pancreatic polypeptide, cholecystokinin, and insulin and subjective ratings of appetite. Weight loss (mean [±SE], 13.5±0.5 kg) led to significant reductions in levels of leptin, peptide YY, cholecystokinin, insulin (P<0.001 for all comparisons), and amylin (P=0.002) and to increases in levels of ghrelin (P<0.001), gastric inhibitory polypeptide (P=0.004), and pancreatic polypeptide (P=0.008). There was also a significant increase in subjective appetite (P<0.001). One year after the initial weight loss, there were still significant differences from baseline in the mean levels of leptin (P<0.001), peptide YY (P<0.001), cholecystokinin (P=0.04), insulin (P=0.01), ghrelin (P<0.001), gastric inhibitory polypeptide (P<0.001), and pancreatic polypeptide (P=0.002), as well as hunger (P<0.001). One year after initial weight reduction, levels of the circulating mediators of appetite that encourage weight regain after diet-induced weight loss do not revert to the levels recorded before weight loss. Long-term strategies to counteract this change may be needed to prevent obesity relapse. (Funded by the National Health and Medical Research Council and others; ClinicalTrials.gov number, NCT00870259.).

Mail and phone interventions for weight loss in a managed-care setting: Weigh-To-Be one-year outcomes.

PubMed

Jeffery, R W; Sherwood, N E; Brelje, K; Pronk, N P; Boyle, R; Boucher, J L; Hase, K

2003-12-01

To describe methods, recruitment success, and 1-y results of a study evaluating the effectiveness of phone- and mail-based weight-loss interventions in a managed care setting. Randomized clinical trial with three groups, that is, usual care, mail intervention, and phone intervention. In total, 1801 overweight members of a managed-care organization (MCO). Height, weight, medical status, and weight-loss history were measured at baseline. Participation in intervention activities was monitored for 12 months in the two active treatment groups. Self-reported weight was obtained at 6 and 12 months. More individuals assigned to mail treatment started it (88%) than did those assigned to phone treatment (69%). However, program completion rates were higher in the phone (36%) than mail (7%) intervention. The mean weight losses were 1.93, 2.38, and 1.47 kg at 6 months in the mail, phone, and usual care groups, respectively. The differences between the phone and usual care groups were statistically significant. The mean weight losses at 12 months did not differ by treatment group (2.28 kg mail, 2.29 kg phone, and 1.92 kg usual care). Greater weight loss was seen in men, older participants, and those with no prior experience in a weight-loss program. Heavier participants and those who reported current treatment for depression lost less weight. Although mail- and phone-based weight-loss programs can be delivered to large numbers of people in an MCO setting, additional work is needed to enhance their clinical efficacy as well as to assess their costs.

Effect of feeding a weight loss food beyond a caloric restriction period on body composition and resistance to weight gain in dogs.

PubMed

Floerchinger, Amanda M; Jackson, Matthew I; Jewell, Dennis E; MacLeay, Jennifer M; Paetau-Robinson, Inke; Hahn, Kevin A

2015-08-15

To determine the effect of feeding a food with coconut oil and supplemental L-carnitine, lipoic acid, lysine, leucine, and fiber on weight loss and maintenance in dogs. Prospective clinical study. 50 overweight dogs. The study consisted of 2 trials. During trial 1, 30 dogs were allocated to 3 groups (10 dogs/group) to be fed a dry maintenance dog food to maintain body weight (group 1) or a dry test food at the same amount on a mass (group 2) or energy (group 3) basis as group 1. During trial 2, each of 20 dogs was fed the test food and caloric intake was adjusted to maintain a weight loss rate of 1% to 2%/wk (weight loss phase). Next, each dog was fed the test food in an amount calculated to maintain the body weight achieved at the end of the weight loss phase (weight maintenance phase). Dogs were weighed and underwent dual-energy x-ray absorptiometry monthly. Metabolomic data were determined before (baseline) and after each phase. During trial 1, dogs in groups 2 and 3 lost significantly more weight than did those in group 1. During trial 2, dogs lost a significant amount of body weight and fat mass but retained lean body mass (LBM) during the weight loss phase and continued to lose body fat but gained LBM during the weight maintenance phase. Evaluation of metabolomic data suggested that fat metabolism and LBM retention were improved from baseline for dogs fed the test food. Results suggested that feeding overweight dogs the test food caused weight loss and improvements in body condition during the weight-maintenance phase, possibly because the food composition improved energy metabolism.

Effective weight loss management with endoscopic gastric plication using StomaphyX device: is it achievable?

PubMed

Ong'uti, Sharon K; Ortega, Gezzer; Onwugbufor, Michael T; Ivey, Gabriel D; Fullum, Terrence M; Tran, Daniel D

2013-01-01

Despite the effectiveness of Roux-en-Y gastric bypass (RYGB) in promoting excess weight loss, 40% of the patients regain weight. Endoscopic gastric plication (EGP) using the StomaphyX device can serve as a less-invasive procedure for promoting the loss of regained weight. Our objective was to evaluate the effectiveness of the StomaphyX device in sustaining ongoing weight loss in patients who have regained weight after RYGB at the Division of Minimally Invasive and Bariatric Surgery, Howard University Hospital. We performed a retrospective chart review of patients undergoing EGP using the StomaphyX device from April 2008 to May 2010. The patient demographics and clinical information were assessed. Effective weight loss and the proportion of weight lost after EGP relative to the weight regained after achieving the lowest weight following RYGB was calculated. A total of 27 patients underwent EGP using the StomaphyX device; of these, most were women (n = 25, 93%) and black (n = 14, 52%), followed by white (n = 11, 42%), and Hispanic (n = 1, 4%). The median interval between RYGB and EGP was 6 years, with an interquartile range of 5-8 years. After the EGP procedure, the median effective weight loss was 37% (interquartile range 24-61%). Of the 27 patients, 18 had ≥6 months of follow-up after EGP. Eleven patients had achieved their lowest weight at 1-3 months, 7 at 6 months, and 3 at 12 months. Of the 18 patients, 13 (72%) experienced an increase in weight after achieving their lowest weight after EGP. The use of the StomaphyX device achieved the maximum effective weight loss during the 1-6-month period after EGP. Copyright © 2013 American Society for Metabolic and Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Daily Self-Monitoring of Body Weight, Step Count, Fruit/Vegetable Intake and Water Consumption: A Feasible and Effective Long-Term Weight Loss Maintenance Approach

PubMed Central

Akers, Jeremy D.; Cornett, Rachel A.; Savla, Jyoti S.; Davy, Kevin P.; Davy, Brenda M.

2012-01-01

Maintenance of weight loss remains a challenge for most individuals, thus practical and effective weight loss maintenance (WTLM) strategies are needed. A two-group (WEV versus WEV+) 12-month WTLM intervention trial was conducted (June 2007–February 2010) to determine the feasibility and effectiveness of weight loss maintenance intervention for older adults using daily self-monitoring of body weight, step count, fruit/vegetable intake and water consumption. Forty weight-reduced (mean weight lost = 6.7 ± 0.6 kg; BMI 29.2 ± 1.1 kg/m2) individuals aged 63 ± 1 yrs, who had previously participated in a 12-week randomized controlled weight loss intervention trial, were instructed to record daily body weight (Weight), step count (Exercise), and fruit/vegetable intake (Vegetable). Experimental group (WEV+) participants were also instructed to consume 16 floz of water before each main meal (i.e., three times daily), and to record daily water intake. Outcome measures included weight change, diet/physical activity behaviors, theoretical constructs related to health behaviors, and other clinical measures. Statistical analyses included growth curve analyses and repeated measures ANOVA. Over 12 months, there was a linear decline in weight (β = −0.32, P < 0.001) and a quadratic trend (β = 0.02, P < 0.01) over time, but no group difference (β = −0.23, P = 0.08). Analysis of the 365 days of self-reported body weight for each participant determined that weight loss was greater over the study period in WEV+ than WEV, corresponding to weight changes of −0.67 kg and 1.00 kg respectively, and an 87% greater weight loss (β = −0.01, P < 0.01). Overall compliance to daily tracking was 76 ± 5%. Daily self-monitoring of weight, physical activity, and fruit/vegetable consumption is a feasible and effective approach for maintaining weight loss for 12 months, and daily self-monitoring of increased water consumption may provide additional WTLM benefits. PMID:22709772

The effects of high protein diets on thermogenesis, satiety and weight loss: a critical review.

PubMed

Halton, Thomas L; Hu, Frank B

2004-10-01

For years, proponents of some fad diets have claimed that higher amounts of protein facilitate weight loss. Only in recent years have studies begun to examine the effects of high protein diets on energy expenditure, subsequent energy intake and weight loss as compared to lower protein diets. In this study, we conducted a systematic review of randomized investigations on the effects of high protein diets on dietary thermogenesis, satiety, body weight and fat loss. There is convincing evidence that a higher protein intake increases thermogenesis and satiety compared to diets of lower protein content. The weight of evidence also suggests that high protein meals lead to a reduced subsequent energy intake. Some evidence suggests that diets higher in protein result in an increased weight loss and fat loss as compared to diets lower in protein, but findings have not been consistent. In dietary practice, it may be beneficial to partially replace refined carbohydrate with protein sources that are low in saturated fat. Although recent evidence supports potential benefit, rigorous longer-term studies are needed to investigate the effects of high protein diets on weight loss and weight maintenance.

Self-expansion is associated with better adherence and obesity treatment outcomes in adults

PubMed Central

Xu, Xiaomeng; Leahey, Tricia M.; Boguszewski, Katherine; Krupel, Katie; Mailloux, Kimberly A.; Wing, Rena R.

2016-01-01

Background Previous studies have shown that self-expansion (e.g., increasing positive self-content via engaging in novel, rewarding activities) is associated with smoking cessation and attenuated cigarette cue-reactivity. Purpose This study examined whether self-expansion is associated with better adherence, weight loss, and physical activity (PA) outcomes within a weight loss intervention. Methods Participants from Shape Up Rhode Island 2012, a Web-based community wellness initiative, took part in a randomized controlled trial that involved a 12-week behavioral weight loss intervention (1). At baseline and post-intervention, objective weights and self-reported self-expansion and PA were obtained from 239 participants. Treatment adherence was assessed objectively. Results Self-expansion during treatment was significantly associated with percent weight loss including clinically significant weight loss (i.e. 5%), minutes of PA, and treatment adherence. These results held after controlling for relevant covariates. Conclusions This is the first study to show that self-expansion is associated with better behavioral weight loss outcomes including weight loss, adherence, and PA. These results suggest that self-expansion is a promising novel target for future research which could inform health interventions. PMID:27436226

Weight Loss and Malnutrition in Patients with Parkinson's Disease: Current Knowledge and Future Prospects

PubMed Central

Ma, Kai; Xiong, Nian; Shen, Yan; Han, Chao; Liu, Ling; Zhang, Guoxin; Wang, Luxi; Guo, Shiyi; Guo, Xingfang; Xia, Yun; Wan, Fang; Huang, Jinsha; Lin, Zhicheng; Wang, Tao

2018-01-01

Parkinson's Disease (PD) is currently considered a systemic neurodegenerative disease manifested with not only motor but also non-motor symptoms. In particular, weight loss and malnutrition, a set of frequently neglected non-motor symptoms, are indeed negatively associated with the life quality of PD patients. Moreover, comorbidity of weight loss and malnutrition may impact disease progression, giving rise to dyskinesia, cognitive decline and orthostatic hypotension, and even resulting in disability and mortality. Nevertheless, the underlying mechanism of weight loss and malnutrition in PD remains obscure and possibly involving multitudinous, exogenous or endogenous, factors. What is more, there still does not exist any weight loss and malnutrition appraision standards and management strategies. Given this, here in this review, we elaborate the weight loss and malnutrition study status in PD and summarize potential determinants and mechanisms as well. In conclusion, we present current knowledge and future prospects of weight loss and malnutrition in the context of PD, aiming to appeal clinicians and researchers to pay a closer attention to this phenomena and enable better management and therapeutic strategies in future clinical practice. PMID:29403371

The effect of liraglutide on weight loss in women with polycystic ovary syndrome: an observational study.

PubMed

Rasmussen, Christina B; Lindenberg, Svend

2014-01-01

The aim of the present study was to evaluate the effect of the glucagon-like peptide-1 analog liraglutide on weight loss in overweight and obese women with polycystic ovary syndrome (PCOS). In an observational study, 84 overweight or obese women with PCOS were treated with liraglutide. Baseline characteristics and weight changes at clinical follow-up were recorded. Main outcome measures were absolute and relative weight loss. In overweight or obese women with PCOS treated with liraglutide for a minimum of 4 weeks, a mean weight loss of 9.0 kg (95% CI: 7.8-10.1, p < 0.0001) and a mean decrease in BMI of 3.2 kg/m(2) (95% CI: 2.8-3.6, p < 0.0001) were found. A weight loss of more than 5 and 10% of baseline weight was seen in 81.7 and 32.9% of patients, respectively. The mean duration of treatment with liraglutide was 27.8 weeks (SD 19.2). Treatment with liraglutide in combination with metformin and lifestyle intervention resulted in a significant weight loss in overweight and obese women with PCOS, indicating that liraglutide may be an effective alternative for weight loss in this group of patients. However, larger placebo-controlled studies are needed to confirm this.

The role of physical activity in producing and maintaining weight loss.

PubMed

Catenacci, Victoria A; Wyatt, Holly R

2007-07-01

The majority of randomized, controlled trials (RCTs) show only modest weight loss with exercise intervention alone, and slight increases in weight loss when exercise intervention is added to dietary restriction. In most RCTs, the energy deficit produced by the prescribed exercise is far smaller than that usually produced by dietary restriction. In prospective studies that prescribed high levels of exercise, enrolled individuals achieved substantially greater weight loss-comparable to that obtained after similar energy deficits were produced by caloric restriction. High levels of exercise might, however, be difficult for overweight or obese adults to achieve and sustain. RCTs examining exercise and its effect on weight-loss maintenance demonstrated mixed results; however, weight maintenance interventions were usually of limited duration and long-term adherence to exercise was problematic. Epidemiologic, cross-sectional, and prospective correlation studies suggest an essential role for physical activity in weight-loss maintenance, and post hoc analysis of prospective trials shows a clear dose-response relationship between physical activity and weight maintenance. This article reviews the role of physical activity in producing and maintaining weight loss. We focus on prospective, RCTs lasting at least 4 months; however, other prospective trials, meta-analyses and large systematic reviews are included. Limitations in the current body of literature are discussed.

Relationships among intrapartum maternal fluid intake, birth type, neonatal output, and neonatal weight loss during the first 48 hours after birth.

PubMed

Lamp, Jane M; Macke, Judi K

2010-01-01

To examine predictive relationships among intrapartum maternal fluid intake, birth type, neonatal output, and neonatal weight loss during the first 48 hours after birth. Prospective descriptive design. Women's center of a 900-bed regional acute care facility with 6,700 births per year. A convenience sample of 200 mother/neonate dyads. The Optimality Index of Murphy and Fullerton guided the inclusion and exclusion criteria to ensure healthy dyads. Data collection began in the intrapartum period and concluded with maternal/neonatal discharge. Measures included maternal intrapartum fluid intake from admission to birth, daily neonatal weight, output, and feedings. Data were analyzed via descriptive statistics, tests of significance and multiple regression. Neonatal weight loss was not significantly related to intrapartum maternal fluid intake. Strong predictors of neonatal weight loss and significant weight loss within the first 48 hours were type of feeding (p=.000) and average number of wet diapers (p=.003). Variables predictive of neonatal weight loss can facilitate identification of at-risk neonates to prevent significant weight loss. Close monitoring of the number of wet diapers in the first 48 hours and accurate daily weights at birth time can lead to early detection and preventive interventions.

Interactive computer-based interventions for weight loss or weight maintenance in overweight or obese people

PubMed Central

Wieland, L. Susan; Falzon, Louise; Sciamanna, Chris N; Trudeau, Kimberlee J; Folse, Suzanne Brodney; Schwartz, Joseph E; Davidson, Karina W

2014-01-01

Background The World Health Organization (WHO) estimates that the number of obese or overweight individuals worldwide will increase to 1.5 billion by 2015. Chronic diseases associated with overweight or obesity include diabetes, heart disease, hypertension and stroke. Objectives To assess the effects of interactive computer-based interventions for weight loss or weight maintenance in overweight or obese people. Search methods We searched several electronic databases, including CENTRAL, MEDLINE, EMBASE, CINAHL, LILACS and PsycINFO, through 25 May 2011. We also searched clinical trials registries to identify studies. We scanned reference lists of included studies and relevant systematic reviews. Selection criteria Studies were included if they were randomized controlled trials or quasi-randomized controlled trials that evaluated interactive computer-based weight loss or weight maintenance programs in adults with overweight or obesity. We excluded trials if the duration of the intervention was less than four weeks or the loss to follow-up was greater than 20% overall. Data collection and analysis Two authors independently extracted study data and assessed risk of bias. Where interventions, control conditions, outcomes and time frames were similar between studies, we combined study data using meta-analysis. Main results We included 14 weight loss studies with a total of 2537 participants, and four weight maintenance studies with a total of 1603 participants. Treatment duration was between four weeks and 30 months. At six months, computer-based interventions led to greater weight loss than minimal interventions (mean difference (MD) −1.5 kg; 95% confidence interval (CI) −2.1 to −0.9; two trials) but less weight loss than in-person treatment (MD 2.1 kg; 95% CI 0.8 to 3.4; one trial). At six months, computer-based interventions were superior to a minimal control intervention in limiting weight regain (MD −0.7 kg; 95% CI −1.2 to −0.2; two trials), but not superior to infrequent in-person treatment (MD 0.5 kg; 95% −0.5 to 1.6; two trials). We did not observe consistent differences in dietary or physical activity behaviors between intervention and control groups in either weight loss or weight maintenance trials. Three weight loss studies estimated the costs of computer-based interventions compared to usual care, however two of the studies were 11 and 28 years old, and recent advances in technology render these estimates unlikely to be applicable to current or future interventions, while the third study was conducted in active duty military personnel, and it is unclear whether the costs are relevant to other settings. One weight loss study reported the cost-effectiveness ratio for a weekly in-person weight loss intervention relative to a computer-based intervention as USD 7177 (EUR 5678) per life year gained (80% CI USD 3055 to USD 60,291 (EUR 2417 to EUR 47,702)). It is unclear whether this could be extrapolated to other studies. No data were identified on adverse events, morbidity, complications or health-related quality of life. Authors’ conclusions Compared to no intervention or minimal interventions (pamphlets, usual care), interactive computer-based interventions are an effective intervention for weight loss and weight maintenance. Compared to in-person interventions, interactive computer-based interventions result in smaller weight losses and lower levels of weight maintenance. The amount of additional weight loss, however, is relatively small and of brief duration, making the clinical significance of these differences unclear. PMID:22895964

Dietary and body weight control: therapeutic education, motivational interviewing and cognitive-behavioral approaches for long-term weight loss maintenance.

PubMed

Golay, Alain

2006-01-01

A diet always induces weight loss in the short term. The loss does not depend on the dietary composition but rather on the caloric deficit. However, a drastic diet often induces binge eating disorders and can lead to a weight gain in the long term. A cognitive-behavioral-nutritional approach allows lasting weight loss and best results with low fat diets in the long term. Therapeutic education is a patient-centered humanistic approach which allows patients to be actors in their own treatment and own diet to improve their success in losing weight and their quality of life. Motivational interviewing and cognitive-behavioral approaches are perfect complements to therapeutic education for long-term weight loss maintenance. Finally, the best diet is the one that the patient can follow in the long term.

Taking weight-loss supplements may elicit liberation from dietary control. A laboratory experiment.

PubMed

Chang, Yevvon Yi-Chi; Chiou, Wen-Bin

2014-01-01

Given that changes in diet and exercise habits are difficult to initiate and maintain, the use of weight-loss supplements has become an appealing alternative approach to weight management for many individuals. The current research examined whether the use of weight-loss supplements induced overly optimistic assessments of progress toward weight reduction, leading to psychological abdication of dietary regulation. Participants were randomly assigned to take either an identified placebo or a purported weight-loss supplement (actually the same placebo). Each participant reported perceived progress toward weight reduction following the manipulation. Consumption of snacks in a taste test and choice of sugary drinks were recorded. The results showed that participants receiving a purported supplement ate more in a taste task and preferred larger quantities of sugar in their reward drinks than did controls. Mediation analysis supported that the perception of progress toward weight reduction contributed to the liberating effect. Using weight-loss supplements may increase perceived progress toward weight reduction but decrease dietary self-regulation. These thought-provoking findings can serve as a basis for educating the public about the myth that they are free to feel liberated from the need to regulate their eating when using weight-loss supplements. Copyright © 2013 Elsevier Ltd. All rights reserved.

Genetic predictors of weight loss and weight regain after intensive lifestyle modification, metformin treatment, or standard care in the Diabetes Prevention Program.

PubMed

Delahanty, Linda M; Pan, Qing; Jablonski, Kathleen A; Watson, Karol E; McCaffery, Jeanne M; Shuldiner, Alan; Kahn, Steven E; Knowler, William C; Florez, Jose C; Franks, Paul W

2012-02-01

We tested genetic associations with weight loss and weight regain in the Diabetes Prevention Program, a randomized controlled trial of weight loss-inducing interventions (lifestyle and metformin) versus placebo. Sixteen obesity-predisposing single nucleotide polymorphisms (SNPs) were tested for association with short-term (baseline to 6 months) and long-term (baseline to 2 years) weight loss and weight regain (6 months to study end). Irrespective of treatment, the Ala12 allele at PPARG associated with short- and long-term weight loss (-0.63 and -0.93 kg/allele, P ≤ 0.005, respectively). Gene-treatment interactions were observed for short-term (LYPLAL1 rs2605100, P(lifestyle*SNP) = 0.032; GNPDA2 rs10938397, P(lifestyle*SNP) = 0.016; MTCH2 rs10838738, P(lifestyle*SNP) = 0.022) and long-term (NEGR1 rs2815752, P(metformin*SNP) = 0.028; FTO rs9939609, P(lifestyle*SNP) = 0.044) weight loss. Three of 16 SNPs were associated with weight regain (NEGR1 rs2815752, BDNF rs6265, PPARG rs1801282), irrespective of treatment. TMEM18 rs6548238 and KTCD15 rs29941 showed treatment-specific effects (P(lifestyle*SNP) < 0.05). Genetic information may help identify people who require additional support to maintain reduced weight after clinical intervention.

Screening the nutritional status in oncology: a preliminary report on 1,000 outpatients.

PubMed

Bozzetti, Federico

2009-03-01

This study presents the preliminary data of a prospective multi-centre investigation on the screening of the nutritional status of cancer outpatients with the purpose to define: (1) prevalence and rate of weight loss and nutritional risk in this patient population, and (2) to assess the association among some patient-dependent, tumour-dependent and therapy-dependent variables with the nutritional status and the nutritional risk. Seventeen centres were involved to collect demographic data (age and sex), oncologic data (site of primary tumour, stage, Eastern Cooperative Oncology Group Performance State, oncologic therapy) and presence and severity of systemic and digestive/nutritional symptoms (fatigue, anorexia, nausea/vomiting, early satiety, dysgeusia/dysosmia, dysphagia/odynophagia, diarrhoea/constipation). Furthermore, the percentage of the weight loss on the usual body weight and the body mass index were computed. The nutritional risk was assessed according to the Nutrition Risk Screening 2002 questionnaire which scores the risk from 0 to 7. On the first 1,000 screened patients, a significant weight loss (>or=10%) and a nutritional risk score >or=3 were observed in 39.7% and 33.8% of patients, respectively. Weight loss was higher in upper gastrointestinal tumours, in advanced stages of disease and in patients with a poor performance status. Similarly, the nutritional risk was higher in esophageal and pancreatic cancer and in those with a worse performance status. There was a good correlation between the severity of anorexia and the rate of the weight loss The majority of patients with no weight loss or a weight loss <10% were not anorectic; on the contrary, the majority of those with more severe weight loss had some degree of anorexia. Weight loss and nutritional risk are frequent in an unselected series of cancer outpatients. Site of primary tumour, stage and performance state appear to be associated, at a preliminary analysis, with significant weight loss and nutritional risk. Anorexia and weight loss are closely related, and this supports the concept that nutritional depletion can play a major role in the onset of malnutrition-cachexia.

Changes in eating, physical activity and related behaviors in a primary care-based weight loss intervention.

PubMed

Volger, S; Wadden, T A; Sarwer, D B; Moore, R H; Chittams, J; Diewald, L K; Panigrahi, E; Berkowitz, R I; Schmitz, K; Vetter, M L

2013-08-01

To examine changes in eating behaviors and physical activity, as well as predictors of weight loss success, in obese adults who participated in a 2-year behavioral weight loss intervention conducted in a primary care setting. A longitudinal, randomized controlled, multisite trial. Three hundred ninety obese (body mass index, 30-50 kg m(-2)) adults, ≥ 21 years, in the Philadelphia region. Participants were assigned to one of three interventions: (1) Usual Care (quarterly primary care provider (PCP) visits that included education on diet and exercise); (2) Brief Lifestyle Counseling (quarterly PCP visits plus monthly lifestyle counseling (LC) sessions about behavioral weight control); or (3) Enhanced Brief LC (the previous intervention with a choice of meal replacements or weight loss medication). At month 24, participants in both Brief LC and Enhanced Brief LC reported significantly greater improvements in mean (± s.e.) dietary restraint than those in Usual Care (4.4 ± 0.5, 4.8 ± 0.5 and 2.8 ± 0.5, respectively; both P-values ≤ 0.016). The percentage of calories from fat, along with fruit and vegetable consumption, did not differ significantly among the three groups. At month 24, both the Brief LC and Enhanced Brief LC groups reported significantly greater increases than usual care in energy expenditure (kcal per week) from moderately vigorous activity (+593.4 ± 175.9, +415.4 ± 179.6 and -70.4 ± 185.5 kcal per week, respectively; both P-values ≤ 0.037). The strongest predictor of weight loss at month 6 (partial R(2)=33.4%, P<0.0001) and at month 24 (partial R(2)=19.3%, P<0.001) was food records completed during the first 6 months. Participants who achieved a 5% weight loss at month 6 had 4.7 times greater odds of maintaining a ≥ 5% weight loss at month 24. A behavioral weight loss intervention delivered in a primary care setting can result in significant weight loss, with corresponding improvements in eating restraint and energy expenditure. Moreover, completion of food records, along with weight loss at month 6, is a strong predictor of long-term weight loss.

Randomized controlled trial of a comprehensive home environment-focused weight loss program for adults

PubMed Central

Gorin, Amy A.; Raynor, Hollie A.; Fava, Joseph; Maguire, Kimberly; Robichaud, Erica; Trautvetter, Jennifer; Crane, Melissa; Wing, Rena R.

2012-01-01

Objective Behavioral weight loss programs (BWL) provide limited instruction on how to change the environmental context of weight-regulating behaviors, perhaps contributing to regain. Drawing on social ecological models, this trial evaluated a comprehensive weight loss program that targeted both an individual’s behavior and their physical and social home environment. Methods Overweight and obese adults (N=201; 48.9±10.5 years; 78.1% women) were randomized to BWL or to BWL plus home environment changes (BWL+H). Groups met weekly for 6 months and bi-monthly for 12 months. BWL+H participants were given items to facilitate healthy choices in their homes (e.g., exercise equipment, portion plates) and attended treatment with a household partner. Weight loss at 6 and 18 months was the primary outcome. Results BWL+H changed many aspects of the home environment and produced better 6 month weight losses than BWL (p=.017). At 18 months, no weight loss differences were observed (p=.19) and rates of regain were equivalent (p=.30). Treatment response was moderated by gender (6 month p=.01; 18 month p=.006). Women lost more weight in BWL+H than BWL at 6 and 18 months, whereas men in BWL lost more weight than those in BWL+H at 18 months. Partners, regardless of gender, lost more weight in BWL+H than BWL at both time points (ps<.0001). Conclusion The home food and exercise environment is malleable and targeting this microenvironment appears to improve initial weight loss, and in women, 18-month outcomes. Research is needed to understand this gender difference and to develop home-focused strategies with more powerful and sustained weight loss effects. PMID:22309885

A 6-month telephone-based weight loss intervention in overweight and obese subjects with idiopathic intracranial hypertension.

PubMed

Weil, Richard; Kovacs, Betty; Miller, Neil; McDermott, Michael P; Wall, Michael; Kupersmith, Mark; Pi-Sunyer, F Xavier

2016-06-01

The purpose of this paper is to measure the change in body weight after a 6-month telephone-based weight loss intervention in overweight and obese subjects with idiopathic intracranial hypertension (IIH) and mild visual loss randomized to receive either acetazolamide or placebo. One hundred sixty-five subjects with IIH, aged 29.1 ± 7.5 (mean ± SD) and BMI 39.9 + 8.3 kg/m 2 , enrolled at 38 academic and private practice sites in North America, participated in this trial. This was a randomized, double-masked, placebo-controlled trial of acetazolamide in subjects with IIH and mild visual loss. All participants received a reduced-sodium, weight-reduction diet and a 6-month telephone-based weight loss intervention. Six-month changes from baseline in body weight, perimetric mean deviation as assessed by automated perimetry and quality of life using the National Eye Institute Visual Function Questionnaire 25 and the 36-item Short Form Health Survey were measured. Mean percent weight change at 6 months was -5.9% ± 6.7% of initial body weight overall, -3.5% ± 5.9% in the placebo group and -7.8% ± 6.8% in the acetazolamide group. Weight change was not associated with changes in either mean deviation or quality of life scores. Patients with IIH and mild visual loss assigned to either acetazolamide or placebo, all of whom received a 6-month telephone-based weight loss intervention, lost an average of 5.9% of initial body weight, consistent with NHLBI guidelines of 5% to 10% of body weight loss for clinically significant health benefit.

Isothermic and fixed intensity heat acclimation methods induce similar heat adaptation following short and long-term timescales.

PubMed

Gibson, Oliver R; Mee, Jessica A; Tuttle, James A; Taylor, Lee; Watt, Peter W; Maxwell, Neil S

2015-01-01

Heat acclimation requires the interaction between hot environments and exercise to elicit thermoregulatory adaptations. Optimal synergism between these parameters is unknown. Common practise involves utilising a fixed workload model where exercise prescription is controlled and core temperature is uncontrolled, or an isothermic model where core temperature is controlled and work rate is manipulated to control core temperature. Following a baseline heat stress test; 24 males performed a between groups experimental design performing short term heat acclimation (STHA; five 90 min sessions) and long term heat acclimation (LTHA; STHA plus further five 90 min sessions) utilising either fixed intensity (50% VO2peak), continuous isothermic (target rectal temperature 38.5 °C for STHA and LTHA), or progressive isothermic heat acclimation (target rectal temperature 38.5 °C for STHA, and 39.0 °C for LTHA). Identical heat stress tests followed STHA and LTHA to determine the magnitude of adaptation. All methods induced equal adaptation from baseline however isothermic methods induced adaptation and reduced exercise durations (STHA = -66% and LTHA = -72%) and mean session intensity (STHA = -13% VO2peak and LTHA = -9% VO2peak) in comparison to fixed (p < 0.05). STHA decreased exercising heart rate (-10 b min(-1)), core (-0.2 °C) and skin temperature (-0.51 °C), with sweat losses increasing (+0.36 Lh(-1)) (p<0.05). No difference between heat acclimation methods, and no further benefit of LTHA was observed (p > 0.05). Only thermal sensation improved from baseline to STHA (-0.2), and then between STHA and LTHA (-0.5) (p<0.05). Both the continuous and progressive isothermic methods elicited exercise duration, mean session intensity, and mean T(rec) analogous to more efficient administration for maximising adaptation. Short term isothermic methods are therefore optimal for individuals aiming to achieve heat adaptation most economically, i.e. when integrating heat acclimation into a pre-competition taper. Fixed methods may be optimal for military and occupational applications due to lower exercise intensity and simplified administration. Copyright © 2015 Elsevier Ltd. All rights reserved.

A systematic review and meta-analysis of mobile devices and weight loss with an intervention content analysis.

PubMed

Lyzwinski, Lynnette Nathalie

2014-06-30

Overweight and obesity constitute leading global public health challenges. Tackling overweight and obesity by influencing human behaviour is a complex task, requiring novel emerging health psychology interventions. The aims of this review will be to determine whether mobile devices induce weight loss and improvements in diet and physical activity levels when compared with standard controls without a weight loss intervention or controls allocated to non-mobile device weight loss interventions. A systematic review on mobile devices and weight loss was conducted. The inclusion criteria were all randomized controlled trials with baseline and post-intervention weight measures in adult subjects >18 years of age without pre-specified co-morbidities. Mobile device specifications included modern, portable devices in the form of smartphones, PDAs, iPods, and Mp3 players. Cohen's d for standardized differences in mean weight loss was calculated. A random effects meta-analysis was generated using Comprehensive meta-analysis software. Theories and intervention content were coded and analysed. A total of 17 studies were identified, of which 12 were primary trials and 5 were secondary analyses. The meta-analysis generated a medium significant effect size of 0.430 (95% CI 0.252-0.609) (p-value ≤ 0.01), favouring mobile interventions. Throughout the systematic review, mobile devices were found to induce weight loss relative to baseline weight. When comparing them with standard no intervention controls as well as controls receiving non-mobile weight loss interventions, results favoured mobile devices for weight loss. Reductions in Body mass index, waist circumference, and percentage body fat were also found in the review. Improvements in the determinants of weight loss in the form of improved dietary intake and physical activity levels were also found. Theory appears to largely inform intervention design, with the most common theories being Social Cognitive Theory, Elaboration Likelihood Theory, Control Theory, and Goal Theory. The use of behavioural change techniques was widespread across the studies, with a minimum of five per intervention. Mobile devices appear to induce positive changes in the behavioural determinants of weight and subsequently are associated with weight loss. Mobile device interventions are heavily informed by theory and behaviour change techniques. The use of theory appears to effectively enhance levels of constructs targeted by interventions.

A Systematic Review and Meta-Analysis of Mobile Devices and Weight Loss with an Intervention Content Analysis

PubMed Central

Lyzwinski, Lynnette Nathalie

2014-01-01

Introduction: Overweight and obesity constitute leading global public health challenges. Tackling overweight and obesity by influencing human behaviour is a complex task, requiring novel emerging health psychology interventions. The aims of this review will be to determine whether mobile devices induce weight loss and improvements in diet and physical activity levels when compared with standard controls without a weight loss intervention or controls allocated to non-mobile device weight loss interventions. Methods: A systematic review on mobile devices and weight loss was conducted. The inclusion criteria were all randomized controlled trials with baseline and post-intervention weight measures in adult subjects >18 years of age without pre-specified co-morbidities. Mobile device specifications included modern, portable devices in the form of smartphones, PDAs, iPods, and Mp3 players. Cohen’s d for standardized differences in mean weight loss was calculated. A random effects meta-analysis was generated using Comprehensive meta-analysis software. Theories and intervention content were coded and analysed. Results: A total of 17 studies were identified, of which 12 were primary trials and 5 were secondary analyses. The meta-analysis generated a medium significant effect size of 0.430 (95% CI 0.252–0.609) (p-value ≤ 0.01), favouring mobile interventions. Throughout the systematic review, mobile devices were found to induce weight loss relative to baseline weight. When comparing them with standard no intervention controls as well as controls receiving non-mobile weight loss interventions, results favoured mobile devices for weight loss. Reductions in Body mass index, waist circumference, and percentage body fat were also found in the review. Improvements in the determinants of weight loss in the form of improved dietary intake and physical activity levels were also found. Theory appears to largely inform intervention design, with the most common theories being Social Cognitive Theory, Elaboration Likelihood Theory, Control Theory, and Goal Theory. The use of behavioural change techniques was widespread across the studies, with a minimum of five per intervention. Conclusion: Mobile devices appear to induce positive changes in the behavioural determinants of weight and subsequently are associated with weight loss. Mobile device interventions are heavily informed by theory and behaviour change techniques. The use of theory appears to effectively enhance levels of constructs targeted by interventions. PMID:25563356

Current concepts in the pharmacological management of obesity.

PubMed

Carek, P J; Dickerson, L M

1999-06-01

The pharmacological management of obesity has gained increasing attention as new weight loss treatments are approved and a significant proportion of the public strives to lose weight. Obesity is associated with a high mortality rate, multiple chronic medical conditions, and carries an enormous financial burden. Obesity is a multifactorial condition, most often due to an imbalance in energy intake and expenditure. Despite the greater focus on management of obesity, weight loss remains a difficult goal to achieve. Obesity is a chronic medical condition that may require long term treatment, therefore the risks and benefits of all pharmacological agents must be carefully considered. Noradrenergic appetite suppressants (ie. phenyl-propanolamine, phentermine) result in weight loss but stimulatory effects limit their use. The serotonergic agents (fenfluramine, dexfenfluramine) were effective weight loss drugs, but were voluntarily withdrawn from the US market last year because of cardiovascular and pulmonary complications. The combination noradrenergic/serotonergic agent sibutramine is indicated for the management of obesity, particularly in the presence of other cardiovascular risk factors. Modest weight loss is achieved with sibutramine, although weight gain is significant after discontinuation. In addition, long term safety data are not yet available. The thermogenic combination of ephedrine plus caffeine is minimally effective, and adverse effects are usually transient. Other thermogenic agents, such as beta3-agonists, are still under investigation. Agents may alter digestion through lipase inhibition (orlistat) or fat substitution (olestra). Orlistat decreases systemic absorption of dietary fat, decreasing body weight and cholesterol. Olestra is a fat substitute that has been incorporated into snack foods. Olestra substitution for dietary fat has not been studied as a weight loss strategy, although olestra has no caloric value and may be beneficial. The use of orlistat and olestra may be limited by gastrointestinal adverse effects. Finally, the manipulation of leptin and neuropeptide Y are under investigation for the treatment of obesity. Pharmacological agents should be used as an aid to a structured diet and exercise regimen in the treatment of obesity. Weight loss agents may result in initial weight loss, but sustained weight loss is not always achieved even with continuation of treatment. The effect of weight loss obtained while using pharmacotherapeutic agents on morbidity and mortality has not been established. Therefore, diet and exercise should be the focus of any weight loss programme. There is a continued need for safe and effective pharmacotherapeutic agents for the treatment of obesity.

The drop it at last study: six-month results of a phone-based weight loss trial.

PubMed

Sherwood, Nancy E; Jeffery, Robert W; Welsh, Ericka M; Vanwormer, Jeff; Hotop, Ann Marie

2010-01-01

To address the translational research question regarding the optimal intervention "dose" to produce the most cost-effective rate of weight loss, we conducted the Drop It At Last (DIAL) study. DIAL is a 6-month pilot randomized trial to examine the efficacy of phone-based weight loss programs with varying levels of treatment contact (10 vs. 20 sessions) in comparison to self-directed treatment. Participants were recruited from the community via mailings and advertisement. Participants were 63 adults with a body mass index between 30 and 39 kg/m(2). Participants received a standard set of print materials and were randomized to either: (1) self-directed treatment; (2) 10 phone coaching sessions; or (3) 20 phone coaching sessions. Measured height, weight, and psychosocial and weight-related self-monitoring measures were collected at baseline and follow-up. General linear models were used to examine 6-month treatment group differences in weight loss and in psychosocial and behavioral measures. Weight losses were -2.3, -3.2, and -4.9 kg in the self-directed, 10-session, and 20-session groups, respectively (p < .21). Participants who completed 10 or more sessions lost more weight (-5.1 kg) compared to those completed four or fewer sessions (-.3 kg, p < .04). Phone-based weight loss program participation is associated with modest weight loss. The optimal dose and timing of intervention warrant further study.

Status of selected nutrients in obese dogs undergoing caloric restriction.

PubMed

Linder, Deborah E; Freeman, Lisa M; Holden, Shelley L; Biourge, Vincent; German, Alexander J

2013-10-24

The purpose of this study was to test the hypothesis that dog plasma concentrations of selected nutrients decrease after undergoing caloric restriction for weight loss. Thirty-one overweight dogs that had successfully lost at least 15% of initial body weight were included in the study. Nutrients that had been previously identified to be at potential risk of deficiency during caloric restriction were measured in plasma (choline, amino acids) and urine (selenium) at the initiation and completion of a standardized weight loss regimen in dogs. Dogs remained healthy throughout the study, and no signs attributable to nutrient deficiency were noted. Percentage weight loss was 28.3% (16.0-40.1%) starting body weight, over a period of 250 days (91-674 days). Median energy intake during the weight loss period was 62 (44 to 74) Kcal/kg(0.75) target weight per day. Choline (P = 0.046) and threonine (P = 0.02) decreased after weight loss. Glycine (P = 0.041), and urinary selenium:creatinine ratio (P = 0.006) both increased after weight loss. There were no other significant differences in plasma nutrient concentrations. Since concentrations of most measured nutrients did not change significantly, the data are not consistent with widespread nutrient deficiency in dogs undergoing caloric restriction using a diet formulated for weight loss. However, the significance of the decrease in plasma choline concentration requires further assessment.

Genetic Predisposition to Weight Loss and Regain With Lifestyle Intervention: Analyses From the Diabetes Prevention Program and the Look AHEAD Randomized Controlled Trials

PubMed Central

Papandonatos, George D.; Pan, Qing; Pajewski, Nicholas M.; Delahanty, Linda M.; Peter, Inga; Erar, Bahar; Ahmad, Shafqat; Harden, Maegan; Chen, Ling; Fontanillas, Pierre; Wagenknecht, Lynne E.; Kahn, Steven E.; Wing, Rena R.; Jablonski, Kathleen A.; Huggins, Gordon S.; Knowler, William C.; Florez, Jose C.

2015-01-01

Clinically relevant weight loss is achievable through lifestyle modification, but unintentional weight regain is common. We investigated whether recently discovered genetic variants affect weight loss and/or weight regain during behavioral intervention. Participants at high-risk of type 2 diabetes (Diabetes Prevention Program [DPP]; N = 917/907 intervention/comparison) or with type 2 diabetes (Look AHEAD [Action for Health in Diabetes]; N = 2,014/1,892 intervention/comparison) were from two parallel arm (lifestyle vs. comparison) randomized controlled trials. The associations of 91 established obesity-predisposing loci with weight loss across 4 years and with weight regain across years 2–4 after a minimum of 3% weight loss were tested. Each copy of the minor G allele of MTIF3 rs1885988 was consistently associated with greater weight loss following lifestyle intervention over 4 years across the DPP and Look AHEAD. No such effect was observed across comparison arms, leading to a nominally significant single nucleotide polymorphism×treatment interaction (P = 4.3 × 10−3). However, this effect was not significant at a study-wise significance level (Bonferroni threshold P < 5.8 × 10−4). Most obesity-predisposing gene variants were not associated with weight loss or regain within the DPP and Look AHEAD trials, directly or via interactions with lifestyle. PMID:26253612

Examining mindfulness as a predictor of weight loss - Findings from the DIABEGG study.

PubMed

Fuller, Nicholas R; Sainsbury, Amanda; Caterson, Ian D; Enarsson, Malin; Denyer, Gareth; Manns, Clare; Swinbourne, Jessica; Q da Luz, Felipe; Fong, Mackenzie; Markovic, Tania P

Identifying individuals who are less likely to respond to a weight loss intervention allows better allocation or focus of resources to achieve better weight loss results. The current study investigated whether baseline levels of mindfulness would predict weight loss during a 12-month diet and exercise intervention. The Five Facet Mindfulness Questionnaire (FFMQ) was administered and body weight measured, at baseline, three, six and 12 months in 140 participants with pre-diabetes or type 2 diabetes mellitus and a body mass index of ≥25kg/m 2 . 137 of 140 participants completed the FFMQ at baseline and were included in this study. There was no correlation between baseline mindfulness scores and weight loss. Mean baseline total FFMQ score was 112.2 [95% confidence interval: 109.4, 115.1] which did not change over the course of the study. Mean baseline body weight was 95.1kg (standard deviation (19.1kg)). There was a significant decrease in weight at month 12 (-3.8kg (±standard deviation 5.8kg)). This is comparable to the weight loss achieved by participants in other interventions of the same duration. The findings suggest that baseline dispositional mindfulness does not predict the amount of weight loss in a lifestyle (diet and exercise) intervention. Copyright © 2016 Asia Oceania Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

Family support is associated with success in achieving weight loss in a group lifestyle intervention for diabetes prevention in Arab Americans.

PubMed

Pinelli, Nicole R; Brown, Morton B; Herman, William H; Jaber, Linda A

2011-01-01

We have recently shown the feasibility of a community-based, culturally-specific, Diabetes Prevention Program-adapted, goal-oriented group lifestyle intervention targeting weight loss in Arab Americans. The objective of this study was to examine factors associated with weight-loss goal attainment at 24-weeks of the lifestyle intervention. We assessed the relationship among demographic, psychosocial, and behavioral measures and the attainment of > or =7% decrease of initial body weight among 71 lifestyle intervention participants. Weight loss goal of > or = 7% of body weight was achieved by 44% of study participants. Demographic and psychosocial factors were not associated with weight loss. Individuals attaining the weight loss goal were more likely to have family support during the core curriculum sessions (70% vs 30%; P=.0023). Decrease in body weight was positively correlated with attendance at sessions (r=.46; P=.0016) and physical activity minutes (r=.66; P<.0001) and negatively correlated with reported caloric intake (r=-.49; P=.0023), fat intake (r=-.52; P=.0010), and saturated fat intake (r=-.39; P=.0175) in women; these trends were similar but not significant in men. Family support was an important predictor of attainment of the weight loss goal. Family-centered lifestyle interventions are likely to succeed in curtailing the rising epidemic of diabetes in the Arab-American Community.

Rapid and highly accurate detection of Drosophila suzukii, spotted wing Drosophila (Diptera: Drosophilidae) by loop-mediated isothermal amplification assays

USDA-ARS?s Scientific Manuscript database

Drosophila suzukii, the spotted wing drosophila (SWD), is currently a major pest that causes severe economic losses to thin-skinned, small fruit growers in North America and Europe. The monitoring and early detection of SWD in the field is of the utmost importance for its proper management. Althou...

Body mass index and weight loss in overweight and obese korean women: the mediating role of body weight perception.

PubMed

Boo, Sunjoo

2013-12-01

This study were to assess the relationships among BMI, body weight perception, and efforts to lose weight in a public sample of Korean women who are overweight and obese and to examine the mediating role of body weight perception on the relationship between BMI and weight loss efforts. This cross-sectional study used data from the 2008 Korea National Health and Nutrition Examination Survey. The sample was 1,739 Korean women 20 years old or older with body mass index (BMI) ≥ 23 kg/m(2). Bivariate relationships among variables of interests were assessed. Three separate regressions were used to test the mediating role of body weight perception on the relationship between BMI and weight loss efforts. BMI and body weight perception were significant correlates of weight loss efforts. BMI was significantly associated with weight perception, but a large proportion of women underestimated their weight. Weight perception partially mediated the relationship between BMI and weight loss efforts in Korean women. In light of the high prevalence of overweight or obesity and the many health consequences associated with obesity, Korean women should be aware of a healthy body weight and try to achieve that weight. Nursing interventions should consider body weight perception to effectively motivate overweight and obese Korean women to lose weight, as necessary. Copyright © 2013. Published by Elsevier B.V.

Estrogen or raloxifene during postmenopausal weight loss: adiposity and cardiometabolic outcomes.

PubMed

Van Pelt, R E; Gozansky, W S; Wolfe, P; Kittelson, J M; Jankowski, C M; Schwartz, R S; Kohrt, W M

2014-04-01

Estrogen-based hormone therapy (HT) attenuates abdominal fat gain after menopause, but whether HT improves abdominal fat loss during weight loss is unknown. It was hypothesized that HT or a selective estrogen receptor modulator (raloxifene) would augment reductions in abdominal visceral fat during weight loss when compared to placebo, potentially increasing improvements in glucose tolerance and lipid profile. Healthy postmenopausal women (n = 119; age 50-70 yr) underwent a 6-month weight-loss (primarily exercise) intervention with randomization to raloxifene (60 mg/d), HT (conjugated estrogens, 0.625 mg/d), or placebo. Outcomes were change in total and abdominal (visceral and subcutaneous) fat mass, lipid profile, and fasting and post-challenge glucose and insulin. Neither HT nor raloxifene augmented loss of total or abdominal fat mass during exercise-induced weight loss when compared with placebo. Weight loss-induced improvements in risk factors were similar among the three groups, except for a greater reduction in fasted glucose in the HT group (difference in change [95%CI] from placebo; -0.40 [-0.76, -0.05]) and greater reductions in LDL (-0.36 [-0.63, -0.09]) and increases in HDL (0.15 [0.07, 0.24]) in both treatment groups. Postmenopausal HT and raloxifene did not increase abdominal fat loss during weight loss, but did improve some cardiometabolic outcomes. Copyright © 2013 The Obesity Society.

Acceptability of financial incentives for maintenance of weight loss in mid-older adults: a mixed methods study.

PubMed

McGill, Bronwyn; O'Hara, Blythe J; Grunseit, Anne C; Bauman, Adrian; Osborne, Dale; Lawler, Luke; Phongsavan, Philayrath

2018-02-13

Health insurers worldwide implement financial incentive schemes to encourage health-related behaviours, including to facilitate weight loss. The maintenance of weight loss is a public health challenge, and as non-communicable diseases become more prevalent with increasing age, mid-older adults could benefit from programs which motivate weight loss maintenance. However, little is understood about their perceptions of using financial incentives to maintain weight loss. We used mixed methods to explore the attitudes and views of participants who had completed an Australian weight loss and lifestyle modification program offered to overweight and obese health insurance members with weight-related chronic diseases, about the acceptability and usefulness of different types of financial incentives to support weight loss maintenance. An online survey was completed by 130 respondents (mean age = 64 years); and a further 28 participants (mean age = 65 years) attended six focus groups. Both independent samples of participants supported a formalised maintenance program. Online survey respondents reported that non-cash (85.2%) and cash (77%) incentives would be potentially motivating; but only 40.5% reported that deposit contracts would motivate weight loss maintenance. Results of in-depth discussions found overall low support for any type of financial incentive, but particularly deposit contracts and lotteries. Some participants expressed that improved health was of more value than a monetary incentive and that they felt personally responsible for their own health, which was at odds with the idea of financial incentives. Others suggested ongoing program and peer support as potentially useful for weight loss maintenance. If financial incentives are considered for mid-older Australian adults in the health insurance setting, program planners will need to balance the discordance between participant beliefs about the individual responsibility for health and their desire for external supports to motivate and sustain weight loss maintenance.

Postmenopausal weight change and incidence of fracture: post hoc findings from Women's Health Initiative Observational Study and Clinical Trials.

PubMed

Crandall, Carolyn J; Yildiz, Vedat O; Wactawski-Wende, Jean; Johnson, Karen C; Chen, Zhao; Going, Scott B; Wright, Nicole C; Cauley, Jane A

2015-01-27

To determine associations between postmenopausal change in body weight and incidence of fracture and associations between voluntary and involuntary weight loss and risk of fracture. Post hoc analysis of data from the Women's Health Initiative Observational Study and Clinical Trials. 40 clinical centers in the United States. 120,566 postmenopausal women, aged 50-79 at baseline (1993-98), followed through 2013 (mean fracture follow-up duration 11 years from baseline). Annualized percentage change in measured body weight from baseline to year 3, classified as stable (<5% change), weight loss (≥ 5%), or weight gain (≥ 5%). Self assessment of whether weight loss was intentional or unintentional. Cox proportional hazards regression models were adjusted for age, race/ethnicity, baseline body mass index (BMI), smoking, alcohol intake, level of physical activity, energy expenditure, calcium and vitamin D intake, physical function score, oophorectomy, hysterectomy, previous fracture, comorbidity score, and drug use. Incident self reported fractures of the upper limbs, lower limbs, and central body; hip fractures confirmed by medical records. Mean participant age was 63.3. Mean annualized percent weight change was 0.30% (95% confidence interval 0.28 to 0.32). Overall, 79,279 (65.6%) had stable weight; 18,266 (15.2%) lost weight; and 23,021 (19.0%) gained weight. Compared with stable weight, weight loss was associated with a 65% higher incidence rates of fracture in hip (adjusted hazard ratio 1.65, 95% confidence interval 1.49 to 1.82), upper limb (1.09, 1.03 to 1.16), and central body (1.30, 1.20 to 1.39); weight gain was associated with higher incidence rates of fracture in upper limb (1.10, 1.05 to 1.18) and lower limb (1.18, 1.12 to 1.25). Compared with stable weight, unintentional weight loss was associated with a 33% higher incidence rates of hip fracture (1.33, 1.19 to 1.47) and increased incidence rates of vertebral fracture (1.16, 1.06 to 1.26); intentional weight loss was associated with increased incidence rates of lower limb fracture (1.11, 1.05 to 1.17) and decreased incidence of hip fracture (0.85, 0.76 to 0.95). Weight gain, weight loss, and intentional weight loss are associated with increased incidence of fracture, but associations differ by fracture location. Clinicians should be aware of fracture patterns after weight gain and weight loss. © Crandall et al 2015.

Nature versus nurture: identical twins and bariatric surgery.

PubMed

Hagedorn, Judith C; Morton, John M

2007-06-01

Genetics and environment both play a role in weight maintenance. Twin studies may help clarify the influence of nature vs nurture in weight loss. We present the largest U.S. experience with monozygotic (MZ) twins undergoing bariatric surgery. We retrospectively reviewed the charts of four sets of MZ twins who underwent Roux-en-Y gastric bypass (RYGBP) surgery and laparoscopic adjustable gastric band (LAGB) placement at three different institutions. BMI and co-morbidities were examined pre- and postoperatively, and laboratory values were recorded. All four sets of twins are female, live together, and have similar professions. Twin cohort 1 had near identical weight loss patterns after open RYGBP surgery in 1996 (preop 146/142 kg; 2 years 82/82; and 10 years 108/107). Twin cohort 1 also both underwent cholecystectomies within the first year postoperatively. Twin cohort 2 underwent laparoscopic RYGBP surgery and also required cholecystectomies in the first postoperative year. Cohort 2 also experienced nearly identical weight loss at 1 year (36.7% vs 37.0% BMI loss). Twin cohort 3 underwent LAGB placement with two different surgeons with differing amounts of weight loss at 6 months (6.5% vs 15.7% BMI loss). Finally, twin cohort 4 underwent laparoscopic RYGBP with 2-year BMI loss of 39% vs 34%. In twin cohort 4, the twin who lost less weight lived apart from her twin and extended family, and her weight loss was less than the twin living with her family. Two sets of MZ twins had identical responses to bariatric surgery. The other two sets of identical twins had differential weight loss results, possibly due to differences in surgical approach and social support. While genetics do exert a strong influence on weight loss and maintenance, this case series demonstrates the potential effect of social support and postoperative management upon postoperative weight loss in the presence of identical genetics.

Molecular Weight Effects on the Viscoelastic Response of a Polyimide

NASA Technical Reports Server (NTRS)

Nicholson, Lee M.; Whitley, Karen S.; Gates, Thomas S.

2000-01-01

The effect of molecular weight on the viscoelastic performance of an advanced polymer (LaRC -SI) was investigated through the use of creep compliance tests. Testing consisted of short-term isothermal creep and recovery with the creep segments performed under constant load. The tests were conducted at three temperatures below the glass transition temperature of each material with different molecular weight. Through the use of time-aging-time superposition procedures, the material constants, material master curves and aging-related parameters were evaluated at each temperature for a given molecular weight. The time-temperature superposition technique helped to describe the effect of temperature on the timescale of the viscoelastic response of each molecular weight. It was shown that the low molecular weight materials have increased creep compliance and creep compliance rate, and are more sensitive to temperature than the high molecular weight materials. Furthermore, a critical molecular weight transition was observed to occur at a weight-average molecular weight of approximately 25000 g/mol below which, the temperature sensitivity of the time-temperature superposition shift factor increases rapidly.

Does metabolic compensation explain the majority of less-than-expected weight loss in obese adults during a short-term severe diet and exercise intervention?

PubMed

Byrne, N M; Wood, R E; Schutz, Y; Hills, A P

2012-11-01

We investigated to what extent changes in metabolic rate and composition of weight loss explained the less-than-expected weight loss in obese men and women during a diet-plus-exercise intervention. In all, 16 obese men and women (41 ± 9 years; body mass index (BMI) 39 ± 6 kg m(-2)) were investigated in energy balance before, after and twice during a 12-week very-low-energy diet(565-650 kcal per day) plus exercise (aerobic plus resistance training) intervention. The relative energy deficit (EDef) from baseline requirements was severe (74%-87%). Body composition was measured by deuterium dilution and dual energy X-ray absorptiometry, and resting metabolic rate (RMR) was measured by indirect calorimetry. Fat mass (FM) and fat-free mass (FFM) were converted into energy equivalents using constants 9.45 kcal per g FM and 1.13 kcal per g FFM. Predicted weight loss was calculated from the EDef using the '7700 kcal kg(-1) rule'. Changes in weight (-18.6 ± 5.0 kg), FM (-15.5 ± 4.3 kg) and FFM (-3.1 ± 1.9 kg) did not differ between genders. Measured weight loss was on average 67% of the predicted value, but ranged from 39% to 94%. Relative EDef was correlated with the decrease in RMR (R=0.70, P<0.01), and the decrease in RMR correlated with the difference between actual and expected weight loss (R=0.51, P<0.01). Changes in metabolic rate explained on average 67% of the less-than-expected weight loss, and variability in the proportion of weight lost as FM accounted for a further 5%. On average, after adjustment for changes in metabolic rate and body composition of weight lost, actual weight loss reached 90% of the predicted values. Although weight loss was 33% lower than predicted at baseline from standard energy equivalents, the majority of this differential was explained by physiological variables. Although lower-than-expected weight loss is often attributed to incomplete adherence to prescribed interventions, the influence of baseline calculation errors and metabolic downregulation should not be discounted.

Dairy foods in a moderate energy restricted diet do not enhance central fat, weight & intra-abdominal adipose tissue loss or reduce adipocyte size & inflammatory markers in overweight & obese adults; Controlled feeding study

USDA-ARS?s Scientific Manuscript database

Background: Research on the role of dairy foods to enhance weight and fat loss when incorporated into a modest weight loss diet has had mixed results. Objective: A 15 week controlled feeding study to answer the question: do dairy foods enhance central fat and weight loss when incorporated in a mode...

An experimental method to simulate incipient decay of wood basidiomycete fungi

Treesearch

Simon Curling; Jerrold E. Winandy; Carol A. Clausen

2000-01-01

At very early stages of decay of wood by basidiomycete fungi, strength loss can be measured from wood before any measurable weight loss. Therefore, strength loss is a more efficient measure of incipient decay than weight loss. However, common standard decay tests (e.g. EN 113 or ASTM D2017) use weight loss as the measure of decay. A method was developed that allowed...

Weight loss and vascular inflammatory markers in overweight women with and without polycystic ovary syndrome.

PubMed

Moran, Lisa J; Noakes, Manny; Wittert, Gary A; Clifton, Peter M; Norman, Robert J

2012-11-01

Polycystic ovary syndrome (PCOS) is associated with increased cardiovascular disease risk. The effect of weight loss on the vascular inflammatory markers plasminogen activator inhibitor-1 (PAI-1), asymmetric dimethylarginine (ADMA), soluble vascular cell adhesion molecule-1 (sVCAM-1) and intracellular adhesion molecule-1 (sICAM-1) is unknown. Overweight women with (n=14) and without (n=13) PCOS of comparable age and body mass index undertook an 8-week weight-loss programme. Women with PCOS had elevated PAI-1, sVCAM-1 and sICAM-1 before and after weight loss compared with the controls. For all women, sVCAM-1 (P=0.026) and sICAM-1 (P=0.04) decreased with weight loss. Women with PCOS have elevated inflammatory markers, which are partially reduced by weight loss. Copyright © 2012 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Strategies to Improve Adherence to Dietary Weight Loss Interventions in Research and Real-World Settings

PubMed Central

2017-01-01

Dietary interventions are the cornerstone of obesity treatment. The optimal dietary approach to weight loss is a hotly debated topic among health professionals and the lay public alike. An emerging body of evidence suggests that a higher level of adherence to a diet, regardless of the type of diet, is an important factor in weight loss success over the short and long term. Key strategies to improve adherence include designing dietary weight loss interventions (such as ketogenic diets) that help to control the increased drive to eat that accompanies weight loss, tailoring dietary interventions to a person’s dietary preferences (and nutritional requirements), and promoting self-monitoring of food intake. The aim of this paper is to examine these strategies, which can be used to improve adherence and thereby increase the success of dietary weight loss interventions. PMID:28696389

Impact of parental weight status on weight loss efforts in Hispanic children

USDA-ARS?s Scientific Manuscript database

Parents have been shown to play an important role in weight loss for children. Parents are typically involved either as models for change or as supporters of children's weight loss efforts. It is likely that overweight/obese parents will need to be involved in changing the environment for themselv...

Increased vegetable and fruit consumption during weight loss effort correlates with increased weight and fat loss

USDA-ARS?s Scientific Manuscript database

Recommendations to increase vegetable and fruit consumption often accompany guidelines for weight loss. A previous study indicated that people who were instructed to count calories lost more weight than those simply instructed to increase vegetable and fruit intake. The objective was to determine if...

Mood and Weight Loss in a Behavioral Treatment Program.

ERIC Educational Resources Information Center

Wing, Rena R.; And Others

1983-01-01

Evaluated the relationship between mood and weight loss for 76 patients participating in two consecutive behavioral treatment programs. Weight losses averaged 12.2 pounds (5.55 kg) during the 10-week program. Positive changes in mood were reported during this interval, and these changes appeared to be related to changes in weight. (Author/RC)

A comparison of categorization criteria used to define successful weight loss maintainers and regainers in the Look AHEAD and DPP trials

USDA-ARS?s Scientific Manuscript database

Introduction: While a variety of lifestyle interventions have resulted in successful weight loss, effective strategies to maintain weight loss are lacking, with many interventions reporting high rates of regain. Identifying characteristics of individuals who successfully maintained their weight afte...

46 CFR 132.350 - Tests and inspections of fire-extinguishing equipment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and halon portable fire extinguishers must be refilled when the weight loss of net content exceeds... weight loss exceeds 10% of weight of charge. Test time delays, alarms, and ventilation shutdowns with.... Inspect hoses and nozzles to be sure they are clean. Halon Weigh cylinders. Recharge if weight loss...

46 CFR 132.350 - Tests and inspections of fire-extinguishing equipment.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and halon portable fire extinguishers must be refilled when the weight loss of net content exceeds... weight loss exceeds 10% of weight of charge. Test time delays, alarms, and ventilation shutdowns with.... Inspect hoses and nozzles to be sure they are clean. Halon Weigh cylinders. Recharge if weight loss...

Effectiveness of a Low-Calorie Weight Loss Program in Moderately and Severely Obese Patients

PubMed Central

Winkler, Julia K.; Schultz, Jobst-Hendrik; Woehning, Annika; Piel, David; Gartner, Lena; Hildebrand, Mirjam; Roeder, Eva; Nawroth, Peter P.; Wolfrum, Christian; Rudofsky, Gottfried

2013-01-01

Aims To compare effectiveness of a 1-year weight loss program in moderately and severely obese patients. Methods The study sample included 311 obese patients participating in a weight loss program, which comprised a 12-week weight reduction phase (low-calorie formula diet) and a 40-week weight maintenance phase. Body weight and glucose and lipid values were determined at the beginning of the program as well as after the weight reduction and the weight maintenance phase. Participants were analyzed according to their BMI class at baseline (30-34.9 kg/m2; 35-39.9 kg/m2; 40-44.9 kg/m2; 45-49.9 kg/m2; ≥50 kg/m2). Furthermore, moderately obese patients (BMI ℋ 40 kg/m2) were compared to severely obese participants (BMI ≥ 40 kg/m2). Results Out of 311 participants, 217 individuals completed the program. Their mean baseline BMI was 41.8 ± 0.5 kg/m2. Average weight loss was 17.9 ± 0.6%, resulting in a BMI of 34.3 ± 0.4 kg/m2 after 1 year (p ℋ 0.001). Overall weight loss was not significantly different in moderately and severely obese participants. Yet, severely obese participants achieved greater weight loss during the weight maintenance phase than moderately obese participants (−3.1 ± 0.7% vs. −1.2 ± 0.6%; p = 0.04). Improvements in lipid profiles and glucose metabolism were found throughout all BMI classes. Conclusion 1-year weight loss intervention improves body weight as well as lipid and glucose metabolism not only in moderately, but also in severely obese individuals. PMID:24135973

Serum aminotransferase changes with significant weight loss: sex and age effects.

PubMed

Suzuki, Ayako; Binks, Martin; Sha, Ronald; Wachholtz, Amy; Eisenson, Howard; Diehl, Anna Mae

2010-02-01

In obese subjects, the liver may be differentially affected by significant weight loss depending on as yet unknown factors. We explored clinical factors associated with serum alanine aminotransferase (ALT) changes during significant weight loss in a residential weight loss program. Clinical data from 362 adults who received a comprehensive weight loss intervention (ie, diets, physical fitness, and behavioral modification) in the program were analyzed. Serum ALT was used as a surrogate marker of liver injury. The ALT changes during the program were calculated to create study outcome categories (improvement, no change, or deterioration of ALT during significant weight loss). Variables of demography, lifestyle, and comorbidities at baseline, and total/rate of weight change during the program were explored for associations with the ALT change categories using multiple logistic regression models. Variation by sex was apparent among predictors of ALT deterioration; men with rapid weight loss and women with higher initial body mass index were more likely to experience ALT deterioration, whereas men with prior alcohol consumption were less likely to experience ALT deterioration even after adjusting for baseline ALT (Ps < .03). Variation by age was apparent among predictors of ALT improvement; younger patients with current smoking and older patients with rapid weight loss, diabetes or impaired fasting glucose, or sleep apnea or who followed a reduced-carbohydrate diet were less likely to experience ALT improvement (Ps < .05). A number of clinical factors influence ALT changes during weight loss in sex- and age-specific manners. The patterns that we detected may have pathophysiologic significance beyond the practical implications of our findings in clinical practice related to underlying changes in fat metabolism. Copyright 2010 Elsevier Inc. All rights reserved.

The relationship of incubational egg weight loss with parthenogenesis in Chinese Painted quail (Coturnix chinensis).

PubMed

Wells, J B; Parker, H M; Kiess, A S; McDaniel, C D

2012-01-01

Parthenogenesis, embryonic development of an unfertilized egg, has been studied extensively in turkeys. Recently it has been revealed that parthenogenesis also occurs in Chinese Painted quail, and the percentage of eggs exhibiting parthenogenesis is negatively correlated with clutch sequence position. In broiler breeders, it has been reported that the first egg of a clutch sequence loses less egg weight during incubation than subsequent eggs. Because the incidence of parthenogenesis is greater and egg weight loss is less in the first egg of a clutch sequence, it is possible that egg weight loss is less in parthenogenetic eggs. Therefore, the objective of this study was to determine if a relationship exists between egg weight loss (a measure of eggshell quality) and parthenogenesis. Daily, individual eggs were collected and labeled. To determine egg weight loss, eggs were weighed before setting and then again after 10 d of incubation. Eggs were stored for 0 to 3 d at 20°C and incubated at 37.5°C. Pearson correlation coefficients were used to determine if relationships existed between egg weight loss and average incidence of parthenogenesis, parthenogen size, egg storage, and average clutch sequence position for all hens examined (157) as well as only for hens that exhibited parthenogenesis (102). The percentage of egg weight loss was negatively correlated with the incidence of parthenogenetic eggs and parthenogen size. However, the percentage of egg weight loss was positively correlated with average clutch position. In conclusion, it appears that eggshell quality possibly influences the incidence of parthenogenesis in Chinese Painted quail eggs because as the percentage of egg weight loss decreases, the incidence of parthenogenesis increases.

Individual- versus group-based financial incentives for weight loss: a randomized, controlled trial.

PubMed

Kullgren, Jeffrey T; Troxel, Andrea B; Loewenstein, George; Asch, David A; Norton, Laurie A; Wesby, Lisa; Tao, Yuanyuan; Zhu, Jingsan; Volpp, Kevin G

2013-04-02

Data on the effectiveness of employer-sponsored financial incentives for employee weight loss are limited. To test the effectiveness of 2 financial incentive designs for promoting weight loss among obese employees. Randomized, controlled trial. (ClinicalTrials.gov: NCT01208350) Children's Hospital of Philadelphia. 105 employees with a body mass index between 30 and 40 kg/m2. 24 weeks of monthly weigh-ins (control group; n = 35); individual incentive, designed as $100 per person per month for meeting or exceeding weight-loss goals (n = 35); and group incentive, designed as $500 per month split among participants within groups of 5 who met or exceeded weight-loss goals (n = 35). Weight loss after 24 weeks (primary outcome) and 36 weeks and changes in behavioral mediators of weight loss (secondary outcomes). Group-incentive participants lost more weight than control participants (mean between-group difference, 4.4 kg [95% CI, 2.0 to 6.7 kg]; P < 0.001) and individual-incentive participants (mean between-group difference, 3.2 kg [CI, 0.9 to 5.5 kg]; P = 0.008). Twelve weeks after incentives ended and after adjustment for 3-group comparisons, group-incentive participants maintained greater weight loss than control group participants (mean between-group difference, 2.9 kg [CI, 0.5 to 5.3 kg]; P = 0.016) but not greater than individual-incentive participants (mean between-group difference, 2.7 kg [CI, 0.4 to 5.0 kg]; P = 0.024). Single employer and short follow-up. A group-based financial incentive was more effective than an individual incentive and monthly weigh-ins at promoting weight loss among obese employees at 24 weeks. National Institute on Aging.

Preoperative assessment of gut hormones does not correlate to weight loss after Roux-en-Y gastric bypass surgery.

PubMed

Werling, Malin; Fändriks, Lars; Vincent, Royce P; Royce, Vincent P; Cross, Gemma F; le Roux, Carel W; Olbers, Torsten

2014-01-01

Roux-en-Y gastric bypass (RYGB) surgery is an effective and frequently used surgical treatment for severe obesity. Postoperative weight loss varies markedly, but biomarkers to predict weight loss outcomes remain elusive. Levels of the satiety gut hormones glucagon like peptide-1 (GLP-1) and peptide YY (PYY) are attenuated in obese patients but elevated after RYGB surgery. We aimed to evaluate the preoperative responses of GLP-1 and PYY to a standard meal as a predictor of weight loss after RYGB surgery. We hypothesized that weak satiety gut hormone responses preoperatively, would predict poor weight loss after RYGB surgery. Preoperatively 43 patients (F = 25/M = 18) had GLP-1 and PYY measured in the fasting state and at 30-minute intervals over 180 minutes after a standard 400 kcal mixed meal. Weight loss was assessed at weight stability after surgery (mean 16.2 mo [CI 15.516.9]). Body mass index decreased from 44.0 kg/m(2) (CI 42.2-45.7) before surgery to 30.3 kg/m(2) (CI 28.4-32.2) after surgery (P<.001). Preoperative GLP-1 and PYY responses to food intake; as delta value between fasting and maximum as well as total responses during 180 minutes did not correlate to total weight loss (GLP-1; rho = .060 and rho = -.089, PYY; rho = -.03 and rho = -.022, respectively) or to excess weight loss % (GLP-1; rho = .051 and rho = -.064, PYY; rho = -.1 and rho = -.088, respectively). Preoperative responses of GLP-1 and PYY to a 400 kcal mixed meal do not correlate to postoperative weight loss after RYGB surgery for morbid obesity. Copyright © 2014 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.

Smartphone applications to support weight loss: current perspectives

PubMed Central

Pellegrini, Christine A; Pfammatter, Angela F; Conroy, David E; Spring, Bonnie

2015-01-01

Lower cost alternatives are needed for the traditional in-person behavioral weight loss programs to overcome challenges of lowering the worldwide prevalence of overweight and obesity. Smartphones have become ubiquitous and provide a unique platform to aid in the delivery of a behavioral weight loss program. The technological capabilities of a smartphone may address certain limitations of a traditional weight loss program, while also reducing the cost and burden on participants, interventionists, and health care providers. Awareness of the advantages smartphones offer for weight loss has led to the rapid development and proliferation of weight loss applications (apps). The built-in features and the mechanisms by which they work vary across apps. Although there are an extraordinary number of a weight loss apps available, most lack the same magnitude of evidence-based behavior change strategies typically used in traditional programs. As features develop and new capabilities are identified, we propose a conceptual model as a framework to guide the inclusion of features that can facilitate behavior change and lead to reductions in weight. Whereas the conventional wisdom about behavior change asserts that more is better (with respect to the number of behavior change techniques involved), this model suggests that less may be more because extra techniques may add burden and adversely impact engagement. Current evidence is promising and continues to emerge on the potential of smartphone use within weight loss programs; yet research is unable to keep up with the rapidly improving smartphone technology. Future studies are needed to refine the conceptual model’s utility in the use of technology for weight loss, determine the effectiveness of intervention components utilizing smartphone technology, and identify novel and faster ways to evaluate the ever-changing technology. PMID:26236766

Tackling overweight and obesity: does the public health message match the science?

PubMed

Hafekost, Katherine; Lawrence, David; Mitrou, Francis; O'Sullivan, Therese A; Zubrick, Stephen R

2013-02-18

Despite the increasing understanding of the mechanisms relating to weight loss and maintenance, there are currently no validated public health interventions that are able to achieve sustained long-term weight loss or to stem the increasing prevalence of obesity in the population. We aimed to examine the models of energy balance underpinning current research about weight-loss intervention from the field of public health, and to determine whether they are consistent with the model provided by basic science. EMBASE was searched for papers published in 2011 on weight-loss interventions. We extracted details of the population, nature of the intervention, and key findings for 27 articles. Most public health interventions identified were based on a simple model of energy balance, and thus attempted to reduce caloric consumption and/or increase physical activity in order to create a negative energy balance. There appeared to be little consideration of homeostatic feedback mechanisms and their effect on weight-loss success. It seems that there has been a lack of translation between recent advances in understanding of the basic science behind weight loss, and the concepts underpinning the increasingly urgent efforts to reduce excess weight in the population. Public health weight-loss interventions seem to be based on an outdated understanding of the science. Their continued failure to achieve any meaningful, long-term results reflects the need to develop intervention science that is integrated with knowledge from basic science. Instead of asking why people persist in eating too much and exercising too little, the key questions of obesity research should address those factors (environmental, behavioral or otherwise) that lead to dysregulation of the homeostatic mechanism of energy regulation. There is a need for a multidisciplinary approach in the design of future weight-loss interventions in order to improve long-term weight-loss success.

Weight control behaviors of highly successful weight loss maintainers: the Portuguese Weight Control Registry.

PubMed

Santos, Inês; Vieira, Paulo N; Silva, Marlene N; Sardinha, Luís B; Teixeira, Pedro J

2017-04-01

To describe key behaviors reported by participants in the Portuguese Weight Control Registry and to determine associations between these behaviors and weight loss maintenance. A total of 388 adults participated in this cross-sectional study. Assessments included demographic information, weight history, weight loss and weight maintenance strategies, dietary intake, and physical activity. Participants lost on average 18 kg, which they had maintained for ~28 months. Their average dietary intake was 2199 kcal/day, with 33 % of energy coming from fat. About 78 % of participants engaged in levels of moderate-plus-vigorous physical activity exceeding 150 min/week (51 % above 250 min/week), with men accumulating 82 more minutes than women (p < 0.05). The most frequently reported strategies for both weight loss and maintenance were keeping healthy foods at home, consuming vegetables regularly, and having daily breakfast. Greater weight loss maintenance was associated with higher levels of physical activity, walking, weight self-monitoring, establishing specific goals, and with reduced portion size use, reduced consumption of carbohydrates, and increased consumption of protein, (p < 0.05). Results indicate that weight loss maintenance is possible through the adoption of a nutritionally-balanced diet and regular participation in physical activity, but also suggest that adopting different (and, to a degree, individualized) set of behavioral strategies is key for achieving success.

Increased circadian prolactin release is blunted after body weight loss in obese premenopausal women.

PubMed

Kok, Petra; Roelfsema, Ferdinand; Langendonk, Janneke G; de Wit, Caroline C; Frölich, Marijke; Burggraaf, Jacobus; Meinders, A Edo; Pijl, Hanno

2006-02-01

We recently showed that prolactin (PRL) release is considerably enhanced in obese women in proportion to the size of their visceral fat mass. PRL release is inhibited by dopamine 2 receptor (D2R) activation, and dietary restriction/weight loss are associated with increased dopaminergic signaling in animals. Therefore, we hypothesized that enhanced PRL release in obese humans would be reversed by weight loss. To evaluate this postulate, we measured 24-h plasma PRL concentrations at 10-min intervals in 11 obese premenopausal women (BMI 33.3 +/- 0.7 kg/m2) before and after weight loss (50% reduction of overweight/15% absolute weight loss, using a very low-calorie diet) in the follicular phase of their menstrual cycle. The 24-h PRL concentration profiles were analyzed by a peak detection program (Cluster) and a wave form-independent deconvolution technique (Pulse). Spontaneous 24-h PRL secretion was significantly reduced in obese women [mean daily release, before 128 +/- 24 vs. after weight loss 110 +/- 17 microg/liter distribution volume (Vdl)(-1) x 24 h, P = 0.05]. Body weight loss particularly blunted PRL secretory burst mass (Pulse area, before 230 +/- 28 vs. after weight loss 221 +/- 31 microg/Vdl(-1) x 24 h, P = 0.03), whereas burst frequency was unaffected (no. of pulses, before 11 +/- 1 vs. after weight loss 12 +/- 1 n/24 h, P = 0.69). Thus elevated PRL secretion rate in obese women is significantly reduced after loss of 50% of overweight. We speculate that amelioration of deficit D2R-mediated neurotransmission and/or diminutions of circulating leptin/estrogen levels might be involved in the physiology of this phenomenon.

Biology of obesity and weight regain: Implications for clinical practice.

PubMed

Rogge, Mary Madeline; Gautam, Bibha

2017-10-01

Weight loss is recommended as first-line therapy for many chronic illnesses, including obesity. Most patients who do successfully lose weight are unable to maintain their reduced weight. Recent research findings are reviewed and synthesized to explain the biology of obesity, adaptation to weight loss, and weight regain. Weight regain is a common consequence of successful weight loss. Current obesity management strategies fail to take into consideration the underlying genetic and environmental causes of obesity. Available treatment modalities create a negative energy balance that stimulates integrated, persistent neurologic, endocrine, muscle, and adipose tissue adaptation to restore body weight and fat mass, independent of lifestyle changes. Understanding the pathophysiology of obesity and weight loss alters nurse practitioners' responsibilities in caring for patients with obesity. They are responsible for expanding assessment and intervention strategies and offering people with obesity realistic expectations for weight loss and regain. They are obligated to explain weight regain when it occurs to minimize patient frustration. Nurse practitioners have the opportunity to adopt new approaches to patient advocacy, especially in the areas of public policy to improve diagnostic tools and adjunctive therapy for people with obesity. ©2017 American Association of Nurse Practitioners.

What Matters in Weight Loss? An In-Depth Analysis of Self-Monitoring

PubMed Central

Hill, James O; Kushner, Robert F; Lindquist, Richard; Brunning, Scott; Margulies, Amy

2017-01-01

Background Using technology to self-monitor body weight, dietary intake, and physical activity is a common practice used by consumers and health companies to increase awareness of current and desired behaviors in weight loss. Understanding how to best use the information gathered by these relatively new methods needs to be further explored. Objective The purpose of this study was to analyze the contribution of self-monitoring to weight loss in participants in a 6-month commercial weight-loss intervention administered by Retrofit and to specifically identify the significant contributors to weight loss that are associated with behavior and outcomes. Methods A retrospective analysis was performed using 2113 participants enrolled from 2011 to 2015 in a Retrofit weight-loss program. Participants were males and females aged 18 years or older with a starting body mass index of ≥25 kg/m2, who also provided a weight measurement at the sixth month of the program. Multiple regression analysis was performed using all measures of self-monitoring behaviors involving weight measurements, dietary intake, and physical activity to predict weight loss at 6 months. Each significant predictor was analyzed in depth to reveal the impact on outcome. Results Participants in the Retrofit Program lost a mean –5.58% (SE 0.12) of their baseline weight with 51.87% (1096/2113) of participants losing at least 5% of their baseline weight. Multiple regression model (R2=.197, P<0.001) identified the following measures as significant predictors of weight loss at 6 months: number of weigh-ins per week (P<.001), number of steps per day (P=.02), highly active minutes per week (P<.001), number of food log days per week (P<.001), and the percentage of weeks with five or more food logs (P<.001). Weighing in at least three times per week, having a minimum of 60 highly active minutes per week, food logging at least three days per week, and having 64% (16.6/26) or more weeks with at least five food logs were associated with clinically significant weight loss for both male and female participants. Conclusions The self-monitoring behaviors of self-weigh-in, daily steps, high-intensity activity, and persistent food logging were significant predictors of weight loss during a 6-month intervention. PMID:28500022

A case of severe anorexia, excessive weight loss and high peptide YY levels after sleeve gastrectomy.

PubMed

Pucci, Andrea; Cheung, Wui Hang; Jones, Jenny; Manning, Sean; Kingett, Helen; Adamo, Marco; Elkalaawy, Mohamed; Jenkinson, Andrew; Finer, Nicholas; Doyle, Jacqueline; Hashemi, Majid; Batterham, Rachel L

2015-01-01

Sleeve gastrectomy (SG) is the second most commonly performed bariatric procedure worldwide. Altered circulating gut hormones have been suggested to contribute post-operatively to appetite suppression, decreased caloric intake and weight reduction. In the present study, we report a 22-year-old woman who underwent laparoscopic SG for obesity (BMI 46 kg/m(2)). Post-operatively, she reported marked appetite reduction, which resulted in excessive weight loss (1-year post-SG: BMI 22 kg/m(2), weight loss 52%, >99th centile of 1-year percentage of weight loss from 453 SG patients). Gastrointestinal (GI) imaging, GI physiology/motility studies and endoscopy revealed no anatomical cause for her symptoms, and psychological assessments excluded an eating disorder. Despite nutritional supplements and anti-emetics, her weight loss continued (BMI 19 kg/m(2)), and she required nasogastric feeding. A random gut hormone assessment revealed high plasma peptide YY (PYY) levels. She underwent a 3 h meal study following an overnight fast to assess her subjective appetite and circulating gut hormone levels. Her fasted nausea scores were high, with low hunger, and these worsened with nutrient ingestion. Compared to ten other post-SG female patients, her fasted circulating PYY and nutrient-stimulated PYY and active glucagon-like peptide 1 (GLP1) levels were markedly elevated. Octreotide treatment was associated with suppressed circulating PYY and GLP1 levels, increased appetite, increased caloric intake and weight gain (BMI 22 kg/m(2) after 6 months). The present case highlights the value of measuring gut hormones in patients following bariatric surgery who present with anorexia and excessive weight loss and suggests that octreotide treatment can produce symptomatic relief and weight regain in this setting. Roux-en-Y gastric bypass and SG produce marked sustained weight reduction. However, there is a marked individual variability in this reduction, and post-operative weight loss follows a normal distribution with extremes of 'good' and 'poor' response.Profound anorexia and excessive weight loss post-SG may be associated with markedly elevated circulating fasted PYY and post-meal PYY and GLP1 levels.Octreotide treatment can produce symptomatic relief and weight regain for post-SG patients that have an extreme anorectic and weight loss response.The present case highlights the value of measuring circulating gut hormone levels in patients with post-operative anorexia and extreme weight loss.

Changes in Body Weight Among People With Type 2 Diabetes Mellitus in the United States, NHANES 2005-2012.

PubMed

Wang, Yiting; Bolge, Susan C; Lopez, Janice M S; Zhu, Vivienne J; Stang, Paul E

2016-06-01

To understand weight loss strategies, weight changes, goals, and behaviors in people with type 2 diabetes mellitus (T2DM) and whether these differ by ethnicity. T2DM was identified by self-reported diagnosis using the NHANES 2005-2012 data, which also included measured and self-reported current body weight and height, self-reported weight the prior year, and self-reported aspired weight. Nineteen weight loss strategies were evaluated for association with ≥5% weight loss or weight gain versus <5% weight change. Among people with T2DM, 88.0% were overweight/obese (body mass index [BMI] ≥25 kg/m(2)) in the prior year and 86.1% the current year. About 60% of the overweight/obese took weight loss actions, mostly using diet-related methods with average weight lost <5%. Two most "effective" methods reported (smoking, taking laxatives/vomiting) are also potentially most harmful. Similar BMI distributions but different goals and behaviors about weight and weight loss were observed across ethnicity. Only physical activity meeting the recommended level and changing eating habits were consistently associated with favorable and statistically significant weight change. Weight management in T2DM is an ongoing challenge, regardless of ethnicity/race. Among overweight/obese T2DM subjects, recommended level of physical activity and changing eating habits were associated with statistically significant favorable weight change. © 2016 The Author(s).

C-reactive protein before and after weight loss in overweight women with and without polycystic ovary syndrome.

PubMed

Moran, Lisa J; Noakes, Manny; Clifton, Peter M; Wittert, Gary A; Belobrajdic, Damien P; Norman, Robert J

2007-08-01

Polycystic ovary syndrome (PCOS) is associated with reproductive and metabolic abnormalities. It is unknown whether overweight women with and without PCOS achieve similar benefits from weight loss for cardiovascular risk factors. Overweight body mass index-matched women with (n = 15) and without (n = 17) PCOS (weight, 95.3 +/- 17.6 kg; body mass index, 35.6 +/- 5.3 kg/m(2), mean +/- sd) followed an 8-wk weight loss regime. All subjects had similar reductions in weight (3.9 +/- 3.6 kg, 3.8%, vs. 4.5 +/- 4.1 kg, 4.7%, respectively, for PCOS and non-PCOS), waist circumference, fat mass, triglycerides, free testosterone, and fasting and postprandial insulin. At baseline, C-reactive protein (CRP) between groups was not significantly different (5.5 +/- 3.1 mg/liter for PCOS vs. 4.9 +/- 3.0 mg/liter for non-PCOS). There was a significant interaction between PCOS status and CRP (P = 0.016) such that CRP decreased with weight loss for non-PCOS women (-1.2 +/- 1.8 mg/liter; P = 0.025) but not for PCOS women. For all women, the change in CRP correlated with the change in weight (r = 0.560; P = 0.003), fat mass (r = 0.477; P = 0.016), and postprandial insulin (r = 0.402; P = 0.046). Adiponectin, IL-6, and TNF-alpha were not significantly different between groups before or after weight loss. Only subjects with baseline CRP levels below the median (4.52 mg/liter) showed increases in adiponectin (0.98 +/- 1.3 microg/liter) (P = 0.015) and greater reductions in triglycerides (P = 0.001) with weight loss. A 4-5% weight loss improved lipid, glucose, and insulin profiles in women with and without PCOS. This degree of weight loss was not effective in lowering CRP concentrations in PCOS women, suggesting that greater weight loss is required in this group to achieve equivalent cardiovascular benefit to non-PCOS women.

Endogenous Opioid Mechanisms Are Implicated in Obesity and Weight Loss in Humans.

PubMed

Burghardt, Paul R; Rothberg, Amy E; Dykhuis, Kate E; Burant, Charles F; Zubieta, Jon-Kar

2015-08-01

Successful long-term weight loss is challenging. Brain endogenous opioid systems regulate associated processes; however, their role in the maintenance of weight loss has not been adequately explored in humans. In a preliminary study, the objective was to assess central μ-opioid receptor (MOR) system involvement in eating behaviors and their relationship to long-term maintenance of weight loss. This was a case-control study with follow-up of the treatment group at 1 year after intervention. The study was conducted at a tertiary care university medical center. Lean healthy (n = 7) and chronically obese (n = 7) men matched for age and ethnicity participated in the study. MOR availability measures were acquired with positron emission tomography and [(11)C]carfentanil. Lean healthy men were scanned twice under both fasted and fed conditions. Obese men were placed on a very low-calorie diet to achieve 15% weight loss from baseline weight and underwent two positron emission tomography scans before and two after weight loss, incorporating both fasted and fed states. Brain MOR availability and activation were measured by reductions in MOR availability (nondisplaceable binding potential) from the fed compared with the fasted-state scans. Baseline MOR nondisplaceable binding potential was reduced in obese compared with the lean and partially recovered obese after weight loss in regions that regulate homeostatic, hedonic, and emotional responses to feeding. Reductions in negative affect and feeding-induced MOR system activation in the right temporal pole were highly correlated in leans but not in obese men. A trend for an association between MOR activation in the right temporal pole before weight loss and weight regain 1 year was found. Although these preliminary studies have a small sample size, these results suggest that obesity and diet-induced weight loss impact central MOR binding and endogenous opioid system function. MOR system activation in response to an acute meal may be related to the risk of weight regain.

EffectS of non-nutritive sWeetened beverages on appetITe during aCtive weigHt loss (SWITCH): Protocol for a randomized, controlled trial assessing the effects of non-nutritive sweetened beverages compared to water during a 12-week weight loss period and a follow up weight maintenance period.

PubMed

Masic, U; Harrold, J A; Christiansen, P; Cuthbertson, D J; Hardman, C A; Robinson, E; Halford, J C G

2017-02-01

Acute and medium-term intervention studies suggest that non-nutritive sweeteners (NNS) are beneficial for weight loss, however there is limited human data on the long-term effects of consuming NNS on weight loss, maintenance, and appetite. Further research is therefore required to elucidate the prolonged impact of NNS consumption on these outcome measures. A randomized parallel groups design will be used to assess whether regular NNS beverage intake is equivalent to a water control in promoting weight loss over 12-weeks (weekly weight loss sessions; Phase I), then supporting weight maintenance over 40-weeks (monthly sessions; Phase II) and subsequently independent weight maintenance over 52-weeks (Phase III) in 432 participants. A subset of these participants (n=116) will complete laboratory-based appetite probe days (15 sessions; 3 sessions each at baseline, at the start of phase I and the end of each phase). A separate subset (n=50) will complete body composition scans (DXA) at baseline and at the end of each phase. All participants will regularly be weighed and will complete questionnaires and cognitive tasks to assess changes in body weight and appetitive behaviours. Measures of physical activity and biochemical markers will also be taken. The trial will assess the efficacy of NNS beverages compared to water during a behavioural weight loss and maintenance programme. We aim to understand whether the impact of NNS on weight, dietary adherence and well-being are beneficial or transient and effects on prolonged successful weight loss and weight maintenance through sustained changes in appetite and eating behaviour. Clinical Trials: NCT02591134; registered: 23.10.2015. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

A Predictive Model of Weight Loss After Roux-en-Y Gastric Bypass up to 5 Years After Surgery: a Useful Tool to Select and Manage Candidates to Bariatric Surgery.

PubMed

Seyssel, Kevin; Suter, Michel; Pattou, François; Caiazzo, Robert; Verkindt, Helene; Raverdy, Violeta; Jolivet, Mathieu; Disse, Emmanuel; Robert, Maud; Giusti, Vittorio

2018-06-19

Different factors, such as age, gender, preoperative weight but also the patient's motivation, are known to impact outcomes after Roux-en-Y gastric bypass (RYGBP). Weight loss prediction is helpful to define realistic expectations and maintain motivation during follow-up, but also to select good candidates for surgery and limit failures. Therefore, developing a realistic predictive tool appears interesting. A Swiss cohort (n = 444), who underwent RYGBP, was used, with multiple linear regression models, to predict weight loss up to 60 months after surgery considering age, height, gender and weight at baseline. We then applied our model on two French cohorts and compared predicted weight to the one finally reached. Accuracy of our model was controlled using root mean square error (RMSE). Mean weight loss was 43.6 ± 13.0 and 40.8 ± 15.4 kg at 12 and 60 months respectively. The model was reliable to predict weight loss (0.37 < R 2  < 0.48) and RMSE between 5.0 and 12.2 kg. High preoperative weight and young age were positively correlated to weight loss, as well as male gender. Correlations between predicted weight and real weight were highly significant in both validation cohorts (R ≥ 0.7 and P < 0.01) and RMSE increased throughout follow-up between 6.2 and 15.4 kg. Our statistical model to predict weight loss outcomes after RYGBP seems accurate. It could be a valuable tool to define realistic weight loss expectations and to improve patient selection and outcomes during follow-up. Further research is needed to demonstrate the interest of this model in improving patients' motivation and results and limit the failures.

Weight Loss Decreases Inherent and Allergic Methacholine Hyperresponsiveness in Mouse Models of Diet-Induced Obese Asthma

PubMed Central

Ather, Jennifer L.; Chung, Michael; Hoyt, Laura R.; Randall, Matthew J.; Georgsdottir, Anna; Daphtary, Nirav A.; Aliyeva, Minara I.; Suratt, Benjamin T.; Bates, Jason H. T.; Irvin, Charles G.; Russell, Sheila R.; Forgione, Patrick M.; Dixon, Anne E.

2016-01-01

Obese asthma presents with inherent hyperresponsiveness to methacholine or augmented allergen-driven allergic asthma, with an even greater magnitude of methacholine hyperresponsiveness. These physiologic parameters and accompanying obese asthma symptoms can be reduced by successful weight loss, yet the underlying mechanisms remain incompletely understood. We implemented mouse models of diet-induced obesity, dietary and surgical weight loss, and environmental allergen exposure to examine the mechanisms and mediators of inherent and allergic obese asthma. We report that the methacholine hyperresponsiveness in these models of inherent obese asthma and obese allergic asthma manifests in distinct anatomical compartments but that both are amenable to interventions that induce substantial weight loss. The inherent obese asthma phenotype, with characteristic increases in distal airspace tissue resistance and tissue elastance, is associated with elevated proinflammatory cytokines that are reduced with dietary weight loss. Surprisingly, bariatric surgery–induced weight loss further elevates these cytokines while reducing methacholine responsiveness to levels similar to those in lean mice or in formerly obese mice rendered lean through dietary intervention. In contrast, the obese allergic asthma phenotype, with characteristic increases in central airway resistance, is not associated with increased adaptive immune responses, yet diet-induced weight loss reduces methacholine hyperresponsiveness without altering immunological variables. Diet-induced weight loss is effective in models of both inherent and allergic obese asthma, and our examination of the fecal microbiome revealed that the obesogenic Firmicutes/Bacteroidetes ratio was normalized after diet-induced weight loss. Our results suggest that structural, immunological, and microbiological factors contribute to the manifold presentations of obese asthma. PMID:27064658

Dietary intakes associated with successful weight loss and maintenance during the Weight Loss Maintenance Trial

PubMed Central

Champagne, Catherine M.; Broyles, Stephanie T; Moran, Laura D.; Cash, Katherine C.; Levy, Erma J.; Lin, Pao-Hwa; Batch, Bryan C.; Lien, Lillian F.; Funk, Kristine L.; Dalcin, Arlene; Loria, Catherine; Myers, Valerie H.

2011-01-01

Background Dietary components effective in weight maintenance efforts have not been adequately identified. Objective To determine impact of changes in dietary consumption on weight loss and maintenance during the Weight Loss Maintenance (WLM) clinical trial. Design WLM was a randomized controlled trial. Successful weight loss participants who completed Phase I of the trial and lost 4kg were randomized to one of three maintenance intervention arms in Phase II and followed for an additional 30 months. Participants/setting The multicenter trial was conducted from 2003–2007. This substudy included 828 successful weight loss participants. Methods Dietary Measures The Block Food Frequency Questionnaire (FFQ) was used to assess nutrient intake levels and food group servings. Carbohydrates, proteins, fats, dietary fiber and fruit/vegetable and dairy servings were utilized as predictor variables. Data collection The FFQ was collected on all participants at study entry (beginning of Phase I). Those randomized to Phase II completed the FFQ at three additional time points; randomization (beginning of Phase II), 12 and 30 months. Intervention The main intervention focused on long term maintenance of weight loss using the Dietary Approaches to Hypertension (DASH) diet. This substudy examined whether changes to specific dietary variables were associated with weight loss and maintenance. Statistical analyses performed Linear regression models that adjusted for change in total energy examined the relationship between changes in dietary intake and weight for each time period. Site, age, race, sex, and a race-sex interaction were included as covariates. Results Participants who substituted protein for fat lost, on average, 0.33 kg per 6-months during Phase I (p<0.0001) and 0.07 kg per 6-months during Phase II (p<0.0001) per 1% increase in protein. Increased intake of fruits and vegetables was associated with weight loss in Phases I and II: 0.29 kg per 6-months (p<0.0001) and 0.04 kg per 6-months (p=0.0062), respectively, per 1-serving increase. Substitution of carbohydrates for fat and protein for carbohydrates were associated with weight loss during both phases. Increasing dairy intake was associated with significant weight loss during Phase II (−0.17 kg per 6-months per 1-serving increase, p=0.0002), but not in Phase I. Dietary fiber revealed no significant findings. Conclusion Increasing fruits, vegetables, and low-fat dairy may help achieve weight loss and maintenance. PMID:22117658

A qualitative study of successful adolescent and young adult weight losers: implications for weight control intervention.

PubMed

Jensen, Chad D; Duraccio, Kara M; Hunsaker, Sanita L; Rancourt, Diana; Kuhl, Elizabeth S; Jelalian, Elissa; Wing, Rena R

2014-12-01

Our study aims to provide an in-depth analysis of behavioral strategies, psychological factors, and social contributors to adolescent weight loss and weight loss maintenance among participants in the Adolescent Weight Control Registry (AWCR). Qualitative analyses were conducted using semi-structured interview data from 40 participants from the AWCR who successfully lost ≥10 lbs and maintained their weight loss for at least one year. In contrast to existing literature, our findings suggest that primary motivating factors for adolescent weight loss may be intrinsic (e.g., desire for better health, desire to improve self-worth) rather than extrinsic. In addition, life transitions (e.g., transition to high school) were identified as substantial motivators for weight-related behavior change. Peer and parental encouragement and instrumental support were widely endorsed as central to success. The most commonly endorsed weight loss maintenance strategies included attending to dietary intake and physical activity levels, and making self-corrections when necessary. Results from this study highlight considerations for future adolescent weight control treatment development.

Impact of carbohydrates on weight regain.

PubMed

Bosy-Westphal, Anja; Müller, Manfred J

2015-07-01

Research on obesity treatment has shifted its focus from weight loss to weight-loss maintenance strategies. The conventional approach of a low-fat diet is challenged by insights from glycemic effects of carbohydrates on body weight regulation. Metabolic and endocrine adaptations to weight loss that contribute to weight regain involve reduced energy expenditure, increased insulin sensitivity, and enhanced orexigenic signals. This review summarizes the impact of carbohydrates on energetic efficiency, partitioning of weight regain as fat and lean mass, and appetite control. Both the amount and frequency of postprandial glycemia add to body weight regulation after weight loss and strengthen the concept of glycemic index and glycemic load. In addition, dietary fiber and slowly or poorly absorbable functional sugars modify gastrointestinal peptides involved in appetite and metabolic regulation and exert prebiotic effects. Current evidence suggests that a low-glycemic load diet with a preference for low-glycemic index foods and integration of slowly digestible, poorly absorbable carbohydrates may improve weight-loss maintenance. Future studies should investigate the health benefits of low glycemic functional sweeteners (e.g., isomaltulose and tagatose).

Predictors of weight loss success. Exercise vs. dietary self-efficacy and treatment attendance.

PubMed

Byrne, Shannon; Barry, Danielle; Petry, Nancy M

2012-04-01

Pre-treatment diet and exercise self-efficacies can predict weight loss success. Changes in diet self-efficacy across treatment appear to be even stronger predictors than baseline levels, but research on changes in exercise self-efficacy is lacking. Using data from a pilot study evaluating tangible reinforcement for weight loss (N=30), we examined the impact of changes in diet and exercise self-efficacy on outcomes. Multiple regression analyses indicated that treatment attendance and changes in exercise self-efficacy during treatment were the strongest predictors of weight loss. Developing weight loss programs that foster the development of exercise self-efficacy may enhance participants' success. Published by Elsevier Ltd.

The Influence of Sleep Disordered Breathing on Weight Loss in a National Weight Management Program

PubMed Central

Janney, Carol A.; Kilbourne, Amy M.; Germain, Anne; Lai, Zongshan; Hoerster, Katherine D.; Goodrich, David E.; Klingaman, Elizabeth A.; Verchinina, Lilia; Richardson, Caroline R.

2016-01-01

Study Objective: To investigate the influence of sleep disordered breathing (SDB) on weight loss in overweight/obese veterans enrolled in MOVE!, a nationally implemented behavioral weight management program delivered by the National Veterans Health Administration health system. Methods: This observational study evaluated weight loss by SDB status in overweight/obese veterans enrolled in MOVE! from May 2008–February 2012 who had at least two MOVE! visits, baseline weight, and at least one follow-up weight (n = 84,770). SDB was defined by International Classification of Diseases, Ninth Revision, Clinical Modification codes. Primary outcome was weight change (lb) from MOVE! enrollment to 6- and 12-mo assessments. Weight change over time was modeled with repeated-measures analyses. Results: SDB was diagnosed in one-third of the cohort (n = 28,269). At baseline, veterans with SDB weighed 29 [48] lb more than those without SDB (P < 0.001). On average, veterans attended eight MOVE! visits. Weight loss patterns over time were statistically different between veterans with and without SDB (P < 0.001); veterans with SDB lost less weight (−2.5 [0.1] lb) compared to those without SDB (−3.3 [0.1] lb; P = 0.001) at 6 months. At 12 mo, veterans with SDB continued to lose weight whereas veterans without SDB started to re-gain weight. Conclusions: Veterans with sleep disordered breathing (SDB) had significantly less weight loss over time than veterans without SDB. SDB should be considered in the development and implementation of weight loss programs due to its high prevalence and negative effect on health. Citation: Janney CA, Kilbourne AM, Germain A, Lai Z, Hoerster KD, Goodrich DE, Klingaman EA, Verchinina L, Richardson CR. The influence of sleep disordered breathing on weight loss in a national weight management program. SLEEP 2016;39(1):59–65. PMID:26350475

The effect of weight loss on anti-Müllerian hormone levels in overweight and obese women with polycystic ovary syndrome and reproductive impairment.

PubMed

Thomson, R L; Buckley, J D; Moran, L J; Noakes, M; Clifton, P M; Norman, R J; Brinkworth, G D

2009-08-01

Anti-Müllerian hormone (AMH) has been proposed as a clinical predictor of improvements in reproductive function following weight loss in overweight and obese women with polycystic ovary syndrome (PCOS). This study aimed to assess whether baseline and/or change in AMH levels with weight loss predict improvements in reproductive function in overweight and obese women with PCOS. Fifty-two overweight and obese women with PCOS and reproductive impairment (age 29.8 +/- 0.8 years, BMI 36.5 +/- 0.7 kg/m(2)) followed a 20-week weight loss programme. AMH, weight, menstrual cyclicity and ovulatory function were assessed at baseline and post-intervention. Participants who responded with improvements in reproductive function (n = 26) had lower baseline AMH levels (23.5 +/- 3.7 versus 32.5 +/- 2.9 pmol/l; P = 0.03) and experienced greater weight loss (-11.7 +/- 1.2 versus -6.4 +/- 0.9 kg; P = 0.001) compared with those who did not respond (n = 26). Logistic regression analysis showed that weight loss and baseline AMH were independently related to improvements in reproductive function (P = 0.002 and P = 0.013, respectively). AMH levels did not change with weight loss in both responders and non-responders. In overweight and obese women with PCOS and reproductive dysfunction, a 20-week weight loss intervention resulted in improvements in reproductive function but no change in AMH levels. ACTRN12606000198527.

Psychological well-being, health behaviors, and weight loss among participants in a residential, Kripalu yoga-based weight loss program.

PubMed

Braun, Tosca D; Park, Crystal L; Conboy, Lisa Ann

2012-01-01

The increasing prevalence of overweight and obesity in humans is a growing public health concern in the United States. Concomitants include poor health behaviors and reduced psychological well-being. Preliminary evidence suggests yoga and treatment paradigms incorporating mindfulness, self-compassion (SC), acceptance, non-dieting, and intuitive eating may improve these ancillary correlates, which may promote long-term weight loss. We explored the impact of a 5-day residential weight loss program, which was multifaceted and based on Kripalu yoga, on health behaviors, weight loss, and psychological well-being in overweight/obese individuals. Thirty-seven overweight/obese program participants (age 32-65, BMI<25) completed validated mind-fulness, SC, lifestyle behavior, and mood questionnaires at baseline, post-program, and 3-month follow-up and reported their weight 1 year after program completion. Significant improvements in nutrition behaviors, SC, mindfulness, stress management, and spiritual growth were observed immediately post-program (n = 31, 84% retention), with medium to large effect sizes. At 3-month follow-up (n = 18, 49% retention), most changes persisted. Physical activity and mood disturbance had improved significantly post-program but failed to reach significance at 3-month follow-up. Self-report weight loss at 1 year (n = 19, 51% retention) was significant. These findings suggest a Kripalu yoga-based, residential weight loss program may foster psychological well-being, improved nutrition behaviors, and weight loss. Given the exploratory nature of this investigation, more rigorous work in this area is warranted.

Obesity Reduction Black Intervention Trial (ORBIT): Design and Baseline Characteristics

PubMed Central

Stolley, Melinda; Schiffer, Linda; Sharp, Lisa; Singh, Vicky; Van Horn, Linda; Dyer, Alan

2008-01-01

Abstract Background Obesity is associated with many chronic diseases, and weight loss can reduce the risk of developing these diseases. Obesity is highly prevalent among Black women, but weight loss treatment for black women has been understudied until recently. The Obesity Reduction black Intervention Trial (ORBIT) is a randomized controlled trial designed to assess the efficacy of a culturally proficient weight loss and weight loss maintenance program for black women. This paper describes the design of the trial, the intervention, and baseline characteristics of the participants. Methods Two hundred thirteen obese black women aged 30–65 years were randomized to the intervention group or a general health control group. The intervention consists of a 6-month weight loss program followed by a 1-year maintenance program. Weight, dietary intake, and energy expenditure are measured at baseline, 6 months, and 18 months. Results More than 40% of participants had a baseline body mass index (BMI) >40 kg/m2 (class III obesity). Intake of fat and saturated fat was higher and consumption of fruit, vegetables, and fiber was lower than currently recommended guidelines. Self-reported moderate to vigorous physical activity was high (median 85 min/day). However, objectively measured physical activity among a subgroup of participants was lower (median 15 min/day). Conclusions Weight loss among obese black women has received inadequate attention in relation to the magnitude of the problem. Factors that contribute to successful weight loss and more importantly, weight loss maintenance need to be identified. PMID:18774895

Contingency management adapted for African-American adolescents with obesity enhances youth weight loss with caregiver participation: a multiple baseline pilot study.

PubMed

Hartlieb, Kathryn Brogan; Naar, Sylvie; Ledgerwood, David M; Templin, Thomas N; Ellis, Deborah A; Donohue, Bradley; Cunningham, Phillippe B

2015-12-07

Contingency management (CM) interventions, which use operant conditioning principles to encourage completion of target behavioral goals, may be useful for improving adherence to behavioral skills training (BST). Research-to-date has yet to explore CM for weight loss in minority adolescents. To examine the effects of CM in improving adolescent weight loss when added to BST. The study utilized an innovative experimental design that builds upon multiple baseline approaches as recommended by the National Institutes of Health. Six obese African-American youth and their primary caregivers living in Detroit, Michigan, USA. Adolescents received between 4 and 12 weeks of BST during a baseline period and subsequently received CM targeting weight loss. Youth weight. Linear mixed effects modeling was used in the analysis. CM did not directly affect adolescent weight loss above that of BST (p=0.053). However, when caregivers were involved in CM session treatment, contingency management had a positive effect on adolescent weight loss. The estimated weight loss due to CM when caregivers also attended was 0.66 kg/week (p<0.001, [95% CI; -1.96, -0.97]) relative to the baseline trajectory. This study demonstrates application of a novel experimental approach to intervention development and demonstrated the importance of parent involvement when delivering contingency management for minority youth weight loss. Lessons learned from contingency management program implementation are also discussed in order to inform practice.

A pilot study of a weight management program with food provision in schizophrenia.

PubMed

Jean-Baptiste, Michel; Tek, Cenk; Liskov, Ellen; Chakunta, Umesh Rao; Nicholls, Sarah; Hassan, Akm Q; Brownell, Kelly D; Wexler, Bruce E

2007-11-01

Obesity is a serious medical problem that disproportionately affects people with severe mental illness. Behavioral strategies aimed at lifestyle modification have proven effective for weight loss in general population but have not been studied adequately among persons with schizophrenia. We have conducted a randomized controlled pilot trial of an established weight loss program, modified for this specific population, and supplemented with a novel food replacement program, as well as practical, community based teaching of shopping and preparing healthy food. The program not only arrested weight gain, and produced meaningful weight loss, but also weight loss continued 6 months after the intervention is completed. Cognitive impairment had no bearing to the extent a participant benefited from the program. As a conclusion, well designed simple behavioral programs can produce lasting weight loss for patients with schizophrenia and comorbid obesity, improve metabolic indices, and possibly decrease significant medical risks associated with obesity.

Mandatory weight loss during the wait for bariatric surgery.

PubMed

Glenn, Nicole M; Raine, Kim D; Spence, John C

2015-01-01

Mandatory presurgical, behavior-induced weight loss, although not standard, is a relatively common practice among bariatric surgical clinics. We explore the patient's experience of this practice using phenomenology. We gathered experiential accounts from 7 individuals waiting to have the procedure at a large publically funded clinic in western Canada. In writing this article, we focused on four phenomenological themes: "just nod your head and carry on"-silencing through the ideal; waiting and weighing-promoting weight consciousness to the weight conscious; paying for surgical approval through weight loss; and presurgical weight loss and questioning the need for weight loss surgery altogether. We contrast the experiential findings with the clinical literature to question the impact and possible (unintended or unexpected) effects the practice might have, particularly on patients' lives. We situate this article within a larger discussion about the possible contribution of experiential knowledge to clinical guidelines, practices, and pedagogies. © The Author(s) 2014.

Acute-Weight-Loss Strategies for Combat Sports and Applications to Olympic Success.

PubMed

Reale, Reid; Slater, Gary; Burke, Louise M

2017-02-01

It is common for athletes in weight-category sports to try to gain a theoretical advantage by competing in weight divisions that are lower than their day-to-day body mass (BM). Weight loss is achieved not only through chronic strategies (body-fat losses) but also through acute manipulations before weigh-in ("making weight"). Both have performance implications. This review focuses on Olympic combat sports, noting that the varied nature of regulations surrounding the weigh-in procedures, weight requirements, and recovery opportunities in these sports provide opportunity for a wider discussion of factors that can be applied to other weight-category sports. The authors summarize previous literature that has examined the performance effects of weightmaking practices before investigating the physiological nature of these BM losses. Practical recommendations in the form of a decision tree are provided to guide the achievement of acute BM loss while minimizing performance decrements.

Genetic variants influencing effectiveness of weight loss strategies.

PubMed

Deram, Sophie; Villares, Sandra M F

2009-03-01

Body weight excess has an increasingly high prevalence in the world. Obesity is a complex disease of multifactorial origin with a polygenic condition affected by environmental factors. Weight loss is a primary strategy to treat obesity and its morbidities. Weight changes through life depend on the interaction of environmental, behavioral and genetic factors. Interindividual variation of weight loss in response to different types of interventions (behavioral, caloric restriction, exercise, drug or surgery) has been observed. In this article, currently available data on the role of candidate gene polymorphisms in weight loss are reviewed. Even though control of weight loss by genotype was described in twin and family studies, it is premature to recommend use of genotyping in the design of therapeutic diets or drug treatment. Future studies will have to be large in order to assess the effects of multiple polymorphisms, and will have to control factors other than diet.

Weight loss from three commercial providers of NHS primary care slimming on referral in North Somerset: service evaluation.

PubMed

Dixon, Karin J L; Shcherba, Sandra; Kipping, Ruth R

2012-12-01

The aim of this study was to analyse the effect of provider, gender and obesity class on outcomes of National Health Service (NHS) slimming on referral. Service evaluation in 12 UK general practices. Obese patients aged ≥16 were referred for 12 sessions to one of three commercial providers. Outcomes at 12 weeks were attendance, BMI, total and percentage weight loss, 5% and 5 kg weight loss and comparison across providers. Linear and multiple regression analyses were used, adjusting for confounders. One thousand four hundred and forty patients were referred; 1047 receiving vouchers and 880 attending at least one session. The mean weight change was -4.8 kg (95% CI: -5.1 to -4.5) and the percentage bodyweight loss was -4.6% (standard deviation: 3.7). Weight Watchers patients lost more weight [-1.15 kg (95% confidence interval, CI: -1.25, -1.04), P < 0.001] and were more likely to lose 5% bodyweight [odds ratio: 1.81 (95% CI: 1.78, 1.83), P < 0.001] than those attending the provider with the least weight loss. NHS slimming on referral can successfully achieve short-term weight loss. Patients attending Weight Watchers were most likely to lose weight than those attendingother providers.

Weight Loss Can Lead to Resolution of Gastroesophageal Reflux Disease Symptoms: A Prospective Intervention Trial

PubMed Central

Singh, Mandeep; Lee, Jaehoon; Gupta, Neil; Gaddam, Srinivas; Smith, Bryan K.; Wani, Sachin B.; Sullivan, Debra K.; Rastogi, Amit; Bansal, Ajay; Donnelly, Joseph E.; Sharma, Prateek

2013-01-01

Objective Weight gain is an important risk factor for gastroesophageal reflux disease (GERD); however, whether weight loss can lead to resolution of GERD symptoms is not clear. Our aim was to measure the impact of weight loss on GERD symptoms. Design and Methods In a prospective cohort study at a tertiary referral center, overweight/obese subjects (BMI 25-39.9 kg/m2) were enrolled in a structured weight loss program. Weight loss strategies included dietary modifications, increased physical activity and behavioral changes. At baseline and at 6 months, BMI and waist circumference were measured and all participants completed a validated reflux disease questionnaire. Results A total of 332 adult subjects, mean age 46 years and 66% women were prospectively enrolled. At baseline, the mean body weight, BMI, and waist circumference were 101 (±18) kg, 35 (±5) kg/m2 and 103 (±13) cm. At 6 months, majority of the subjects (97%) lost weight (average weight loss: 13 ± 7.7 kg) and as compared with baseline, there was a significant decrease in the overall prevalence of GERD (15 vs. 37%; P < 0.01) and the mean GERD symptom score (1.8 vs. 5.5; P < 0.01). Overall, 81% of the subjects had reduction in GERD symptom scores; 65% had complete resolution and 15% had partial resolution of reflux symptoms. There was a significant correlation between % body weight loss and reduction in GERD symptom scores (r = 0.17, P < 0.05). Conclusions In conclusion, the overall prevalence of GERD symptoms is high (37%) in overweight and obese subjects. A structured weight loss program can lead to complete resolution of GERD symptoms in the majority of these subjects. PMID:23532991

Behavioral Weight Loss Treatment in Antipsychotic Treated Youth.

PubMed

Nicol, Ginger E; Kolko, Rachel P; Mills, Monica; Gunnarsdottir, Thrudur; Yingling, Michael D; Schweiger, Julia A; Lenze, Eric J; Newcomer, John W; Wilfley, Denise

2016-05-01

Antipsychotic-treated youth have increased risk for the development of obesity and type 2 diabetes. Behavioral weight loss treatments show promise in reducing obesity and diabetes risk in antipsychotic treated adults, but have received no study in antipsychotic treated youth. We describe a rationale for behavioral weight loss interventions in high-weight antipsychotic treated youth, and report behavioral, anthropomorphic, and metabolic findings from a case series of obese antipsychotic-treated adolescents participating in a short-term, family-based behavioral weight loss intervention. We adapted the Traffic Light Plan, a 16-week family-based weight loss intervention that promotes healthy energy balance using the colors of the traffic light to categorize the nutritional value of foods and intensity of physical activity, adapting a social ecological framework to address health behavior change in multiple social contexts. The intervention was administered to three obese adolescents with long-term antipsychotic medication exposure. Efficacy of the intervention was evaluated with a battery of anthropomorphic and metabolic assessments including weight, body mass index percentile, whole body adiposity, liver fat content, and fasting plasma glucose and lipids. Participants and their parents also filled out a treatment satisfaction questionnaire upon study completion. Two males and 1 female (all aged 14 years) participated. All 3 participants attended all 16 sessions, and experienced beneficial changes in adiposity, fasting lipids and liver fat content associated with weight stabilization or weight loss. Adolescents and their parents all reported a high level of satisfaction with the treatment. Family-based behavioral weight loss treatment can be feasibly delivered and is acceptable to antipsychotic-treated youth and their families. Randomized controlled trials are needed to fully evaluate the effectiveness and acceptability of behavioral weight loss interventions in antipsychotic treated youth and their families.

Social facilitation maintenance treatment for adults with obesity: study protocol for a randomised-controlled feasibility study (SFM study).

PubMed

Hilbert, Anja

2016-08-31

The long-term success of non-surgical weight loss treatment in adults with obesity is limited by substantial relapse, and only a few evidence-based weight loss maintenance treatments exist. This clinical trial investigates the feasibility and efficacy of a social facilitation maintenance programme for weight loss maintenance, tailored to meet the needs of obese adults who have undergone a lifestyle weight loss intervention. In a single-centre, open feasibility trial, 72 adults currently or previously obese or overweight who have undergone a lifestyle weight loss intervention are centrally randomised to 4 months of social facilitation maintenance treatment or treatment as a usual control condition. In 16 outpatient group sessions, the social facilitation maintenance treatment, based on a socioecological model and on evidence supporting social facilitation as a key process in maintaining weight loss, focuses on promoting interpersonal relationships to build up a healthy lifestyle for long-term weight loss maintenance. Primary outcome is the amount of weight regain at 6-month follow-up, compared with pre-treatment weight, derived from measured body weight. Secondary outcomes address feasibility, including recruitment, attrition, assessment non-completion, compliance and patients' programme evaluation; and in comparison with pre-weight loss maintenance, social and interpersonal functioning, eating behaviour and physical activity, psychological and physical symptoms, body composition and risk of comorbidity, and quality of life at post-treatment and follow-up assessments. The study was approved by the Ethical Committee at the University of Leipzig (165-13-15072013). The study results will be disseminated through peer-reviewed publications. DRKS00005182. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Clinical Effectiveness of Weight Loss and Weight Maintenance Interventions for Men: A Systematic Review of Men-Only Randomized Controlled Trials (The ROMEO Project).

PubMed

Robertson, Clare; Avenell, Alison; Stewart, Fiona; Archibald, Daryll; Douglas, Flora; Hoddinott, Pat; van Teijlingen, Edwin; Boyers, Dwayne

2017-07-01

Men are underrepresented in obesity services, suggesting current weight loss service provision is suboptimal. This systematic review evaluated evidence-based strategies for treating obesity in men. Eight bibliographic databases and four clinical trials' registers were searched to identify randomized controlled trials (RCTs) of weight loss interventions in men only, with mean/median body mass index of ≥30 kg/m 2 (or ≥28 kg/m 2 with cardiac risk factors), with a minimum mean/median duration of ≥52 weeks. Interventions included diet, physical activity, behavior change techniques, orlistat, or combinations of these; compared against each other, placebo, or a no intervention control group; in any setting. Twenty-one reports from 14 RCTs were identified. Reducing diets produced more favorable weight loss than physical activity alone (mean weight change after 1 year from a reducing diet compared with an exercise program -3.2 kg, 95% confidence interval -4.8 to -1.6 kg, reported p < .01). The most effective interventions combined reducing diets, exercise, and behavior change techniques (mean difference in weight at 1 year compared with no intervention was -4.9 kg, 95% confidence interval -5.9 to -4.0, reported p < .0001). Group interventions produced favorable weight loss results. The average reported participant retention rate was 78.2%, ranging from 44% to 100% retention, indicating that, once engaged, men remained committed to a weight loss intervention. Weight loss for men is best achieved and maintained with the combination of a reducing diet, increased physical activity, and behavior change techniques. Strategies to increase engagement of men with weight loss services to improve the reach of interventions are needed.

Clinical Effectiveness of Weight Loss and Weight Maintenance Interventions for Men: A Systematic Review of Men-Only Randomized Controlled Trials (The ROMEO Project)

PubMed Central

Robertson, Clare; Avenell, Alison; Stewart, Fiona; Archibald, Daryll; Douglas, Flora; Hoddinott, Pat; van Teijlingen, Edwin; Boyers, Dwayne

2015-01-01

Men are underrepresented in obesity services, suggesting current weight loss service provision is suboptimal. This systematic review evaluated evidence-based strategies for treating obesity in men. Eight bibliographic databases and four clinical trials’ registers were searched to identify randomized controlled trials (RCTs) of weight loss interventions in men only, with mean/median body mass index of ≥30 kg/m2 (or ≥28 kg/m2 with cardiac risk factors), with a minimum mean/median duration of ≥52 weeks. Interventions included diet, physical activity, behavior change techniques, orlistat, or combinations of these; compared against each other, placebo, or a no intervention control group; in any setting. Twenty-one reports from 14 RCTs were identified. Reducing diets produced more favorable weight loss than physical activity alone (mean weight change after 1 year from a reducing diet compared with an exercise program −3.2 kg, 95% confidence interval −4.8 to −1.6 kg, reported p < .01). The most effective interventions combined reducing diets, exercise, and behavior change techniques (mean difference in weight at 1 year compared with no intervention was −4.9 kg, 95% confidence interval −5.9 to −4.0, reported p < .0001). Group interventions produced favorable weight loss results. The average reported participant retention rate was 78.2%, ranging from 44% to 100% retention, indicating that, once engaged, men remained committed to a weight loss intervention. Weight loss for men is best achieved and maintained with the combination of a reducing diet, increased physical activity, and behavior change techniques. Strategies to increase engagement of men with weight loss services to improve the reach of interventions are needed. PMID:26130729

Maintained intentional weight loss reduces cardiovascular outcomes: results from the Sibutramine Cardiovascular OUTcomes (SCOUT) trial.

PubMed

Caterson, I D; Finer, N; Coutinho, W; Van Gaal, L F; Maggioni, A P; Torp-Pedersen, C; Sharma, A M; Legler, U F; Shepherd, G M; Rode, R A; Perdok, R J; Renz, C L; James, W P T

2012-06-01

The Sibutramine Cardiovascular OUTcomes trial showed that sibutramine produced greater mean weight loss than placebo but increased cardiovascular morbidity but not mortality. The relationship between 12-month weight loss and subsequent cardiovascular outcomes is explored. Overweight/obese subjects (N = 10 744), ≥55 years with cardiovascular disease and/or type 2 diabetes mellitus, received sibutramine plus weight management during a 6-week Lead-in Period before randomization to continue sibutramine (N = 4906) or to receive placebo (N = 4898). The primary endpoint was the time from randomization to first occurrence of a primary outcome event (non-fatal myocardial infarction, non-fatal stroke, resuscitated cardiac arrest or cardiovascular death). For the total population, mean weight change during Lead-in Period (sibutramine) was -2.54 kg. Post-randomization, mean total weight change to Month 12 was -4.18 kg (sibutramine) or -1.87 kg (placebo). Degree of weight loss during Lead-in Period or through Month 12 was associated with a progressive reduction in risk for the total population in primary outcome events and cardiovascular mortality over the 5-year assessment. Although more events occurred in the randomized sibutramine group, on an average, a modest weight loss of approximately 3 kg achieved in the Lead-in Period appeared to offset this increased event rate. Moderate weight loss (3-10 kg) reduced cardiovascular deaths in those with severe, moderate or mild cardiovascular disease. Modest weight loss over short-term (6 weeks) and longer-term (6-12 months) periods is associated with reduction in subsequent cardiovascular mortality for the following 4-5 years even in those with pre-existing cardiovascular disease. While the sibutramine group experienced more primary outcome events than the placebo group, greater weight loss reduced overall risk of these occurring in both groups. © 2011 Blackwell Publishing Ltd.

A 6‐month telephone‐based weight loss intervention in overweight and obese subjects with idiopathic intracranial hypertension

PubMed Central

Kovacs, Betty; Miller, Neil; McDermott, Michael P.; Wall, Michael; Kupersmith, Mark; Pi‐Sunyer, F. Xavier

2016-01-01

Summary Objectives The purpose of this paper is to measure the change in body weight after a 6‐month telephone‐based weight loss intervention in overweight and obese subjects with idiopathic intracranial hypertension (IIH) and mild visual loss randomized to receive either acetazolamide or placebo. Methods One hundred sixty‐five subjects with IIH, aged 29.1 ± 7.5 (mean ± SD) and BMI 39.9 + 8.3 kg/m2, enrolled at 38 academic and private practice sites in North America, participated in this trial. This was a randomized, double‐masked, placebo‐controlled trial of acetazolamide in subjects with IIH and mild visual loss. All participants received a reduced‐sodium, weight‐reduction diet and a 6‐month telephone‐based weight loss intervention. Six‐month changes from baseline in body weight, perimetric mean deviation as assessed by automated perimetry and quality of life using the National Eye Institute Visual Function Questionnaire 25 and the 36‐item Short Form Health Survey were measured. Results Mean percent weight change at 6 months was −5.9% ± 6.7% of initial body weight overall, −3.5% ± 5.9% in the placebo group and −7.8% ± 6.8% in the acetazolamide group. Weight change was not associated with changes in either mean deviation or quality of life scores. Conclusion Patients with IIH and mild visual loss assigned to either acetazolamide or placebo, all of whom received a 6‐month telephone‐based weight loss intervention, lost an average of 5.9% of initial body weight, consistent with NHLBI guidelines of 5% to 10% of body weight loss for clinically significant health benefit. PMID:29071096

Can limiting dietary variety assist with reducing energy intake and weight loss?☆

PubMed Central

Raynor, Hollie A.

2013-01-01

Due to the high prevalence of overweight and obesity, developing strategies to improve weight loss and weight loss maintenance is imperative. One dietary environmental variable that has received little attention in being targeted in an intervention to assist with obesity treatment is dietary variety. Experimental research has consistently shown that greater dietary variety increases consumption, with the effect of variety on consumption hypothesized to be a consequence of the differential experience of the more varied sensory properties of food under those conditions with greater dietary variety. As reduced energy intake is required for weight loss, limiting variety, particularly in food groups that are high in energy-density and low in nutrient-density, may assist with reducing energy intake and improving weight loss. A series of investigations, both observational and experimental, were conducted to examine if limiting variety in an energydense, non-nutrient-dense food group, snack foods (i.e., cookies, chips), assisted with reducing energy intake of the food group and improving weight loss. Results of the investigations suggest that a prescription for limiting variety in a food group can be implemented during obesity treatment, limiting variety is associated with the occurrence of monotony, and that reducing food group variety is related to decreased consumption of that food group. Future research is needed to ascertain the long-term effect of prescriptions targeting dietary variety on weight loss and weight loss maintenance. PMID:22450259

Psychological predictors of weight loss after bariatric surgery: a review of the recent research.

PubMed

Wimmelmann, Cathrine L; Dela, Flemming; Mortensen, Erik L

2014-01-01

Morbid obesity is the fastest growing BMI group in the U.S. and the prevalence of morbid obesity worldwide has never been higher. Bariatric surgery is the most effective treatment for severe forms of obesity especially with regard to a sustained long-term weight loss. Psychological factors are thought to play an important role for maintaining the surgical weight loss. However, results from prior research examining preoperative psychological predictors of weight loss outcome are inconsistent. The aim of this article was to review more recent literature on psychological predictors of surgical weight loss. We searched PubMed, PsycInfo and Web of Science, for original prospective studies with a sample size >30 and at least one year follow-up, using a combination of search terms such as 'bariatric surgery', 'morbid obesity', 'psychological predictors', and 'weight loss'. Only studies published after 2003 were included. 19 eligible studies were identified. Psychological predictors of surgical weight loss investigated in the reviewed studies include cognitive function, personality, psychiatric disorder, and eating behaviour. In general, recent research remains inconsistent, but the findings suggest that pre-surgical cognitive function, personality, mental health, composite psychological variables and binge eating may predict post-surgical weight loss to the extent that these factors influence post-operative eating behaviour. Copyright © 2013 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

Selecting a Weight-Loss Program

MedlinePlus

... 3700, April 2008. Healthy Weight Tip Choose weight-loss programs that encourage healthy behaviors that help you lose weight gradually and maintain your weight over time. Looking for easy-to-use information for eating healthy on the go? The Maintaining a Healthy Weight On the Go pocket guide ...

Gestational Weight Gain and Post-Partum Weight Loss Among Young, Low-Income, Ethnic Minority Women

PubMed Central

ROTHBERG, Bonnie E. Gould; MAGRIPLES, Urania; KERSHAW, Trace S.; RISING, Sharon Schindler; ICKOVICS, Jeannette R.

2010-01-01

Objective Document weight change trajectories that lead to gestational weight gain or postpartum weight loss outside clinical recommendations established by Institute of Medicine (IOM). Methods Women aged 14-25 receiving prenatal care and delivering singleton infants at term (N=427). Medical record review and four structured interviews conducted: second and third trimester, 6- and 12-months postpartum. Longitudinal mixed modeling to evaluate weight change trajectories. Results Only 22% of participants gained gestational weight within IOM guidelines. 62% exceeded maximum recommendations -- more common among those overweight/obese (BMI≥25.0; p<0.0001). 52% retained ≥10 pounds one-year postpartum. Increased weight gain and retention documented among smokers and women with pregnancy-induced hypertension; breastfeeding promoted postpartum weight loss (all p<.02). BMI by race interaction suggested healthier outcomes for Latinas (p=0.02). Conclusion Excessive pregnancy weight gain and inadequate postpartum weight loss are highly prevalent among young low-income ethnic minority women. Pregnancy and postpartum are critical junctures for weight management interventions. PMID:20974459

Tools for Successful Weight Management in Primary Care

PubMed Central

Turer, Christy Boling

2015-01-01

Obesity is one of the most pervasive and costly public-health problems. Clinicians need effective tools to address weight management in primary care, including evaluation and communication methods, guideline-based weight-management interventions, and safe and effective weight-loss medications and surgery. The objective of this Grand-Rounds presentation is to provide practicing clinicians with the latest information regarding effective ways to care for and communicate with patients about weight loss; evidence-based guidelines for selecting weight-management therapies; and safety, efficacy, and adverse effects of weight-loss medications and surgery. PMID:26218666

The Influence of Sleep Disordered Breathing on Weight Loss in a National Weight Management Program.

PubMed

Janney, Carol A; Kilbourne, Amy M; Germain, Anne; Lai, Zongshan; Hoerster, Katherine D; Goodrich, David E; Klingaman, Elizabeth A; Verchinina, Lilia; Richardson, Caroline R

2016-01-01

To investigate the influence of sleep disordered breathing (SDB) on weight loss in overweight/obese veterans enrolled in MOVE!, a nationally implemented behavioral weight management program delivered by the National Veterans Health Administration health system. This observational study evaluated weight loss by SDB status in overweight/obese veterans enrolled in MOVE! from May 2008-February 2012 who had at least two MOVE! visits, baseline weight, and at least one follow-up weight (n = 84,770). SDB was defined by International Classification of Diseases, Ninth Revision, Clinical Modification codes. Primary outcome was weight change (lb) from MOVE! enrollment to 6- and 12-mo assessments. Weight change over time was modeled with repeated-measures analyses. SDB was diagnosed in one-third of the cohort (n = 28,269). At baseline, veterans with SDB weighed 29 [48] lb more than those without SDB (P < 0.001). On average, veterans attended eight MOVE! visits. Weight loss patterns over time were statistically different between veterans with and without SDB (P < 0.001); veterans with SDB lost less weight (-2.5 [0.1] lb) compared to those without SDB (-3.3 [0.1] lb; P = 0.001) at 6 months. At 12 mo, veterans with SDB continued to lose weight whereas veterans without SDB started to re-gain weight. Veterans with sleep disordered breathing (SDB) had significantly less weight loss over time than veterans without SDB. SDB should be considered in the development and implementation of weight loss programs due to its high prevalence and negative effect on health. © 2016 Associated Professional Sleep Societies, LLC.

Applying economic incentives to increase effectiveness of an outpatient weight loss program (TRIO) - A randomized controlled trial.

PubMed

Finkelstein, Eric A; Tham, Kwang-Wei; Haaland, Benjamin A; Sahasranaman, Aarti

2017-07-01

The prevalence of overweight and obesity has more than doubled in the past three decades, leading to rising rates of non-communicable diseases. This study tests whether adding a payment/rewards (term reward) program to an existing evidence-based weight loss program can increase weight loss and weight loss maintenance. We conducted a parallel-group randomized controlled trial from October 2012 to October 2015 with 161 overweight or obese individuals randomized to either control or reward arm in a 1:2 ratio. Control and reward arm participants received a four month weight loss program at the LIFE (Lifestyle Improvement and Fitness Enhancement) Centre at Singapore General Hospital. Those in the reward arm paid a fee of S$165.00 (1US$ = 1.35S$) to access a program that provided rewards of up to S$660 for meeting weight loss and physical activity goals. Participants could choose to receive rewards as guaranteed cash payments or a lottery ticket with a 1 in 10 chance of winning but with the same expected value. The primary outcome was weight loss at months 4, 8, and 12. 161 participants were randomized to control (n = 54) or reward (n = 107) arms. Average weight loss was more than twice as great in the reward arm compared to the control arm at month 4 when the program concluded (3.4 kg vs 1.4 kg, p < 0.01), month 8 when rewards concluded (3.3 kg vs 1.8 kg, p < 0.05), and at month 12 (2.3 kg vs 0.8 kg, p < 0.05). These results reveal that a payment/rewards program can be used to improve weight loss and weight loss maintenance when combined with an evidence-based weight loss program. Future efforts should attempt to replicate this approach and identify how to cost effectively expand these programs to maximize their reach. This study is registered at www.clinicaltrials.gov (Identifier: NCT01533454). Copyright © 2017 Elsevier Ltd. All rights reserved.

Lunch eating predicts weight-loss effectiveness in carriers of the common allele at PERILIPIN1: the ONTIME (Obesity, Nutrigenetics, Timing, Mediterranean) study.

PubMed

Garaulet, Marta; Vera, Beatriz; Bonnet-Rubio, Gemma; Gómez-Abellán, Purificación; Lee, Yu-Chi; Ordovás, José M

2016-10-01

We propose that eating lunch late impairs the mobilization of fat from adipose tissue, particularly in carriers of PERILIPIN1 (PLIN1) variants. The aim was to test the hypothesis that PLIN1, a circadian lipid-stabilizing protein in the adipocyte, interacts with the timing of food intake to affect weight loss. A total of 1287 overweight and obese subjects [229 men and 1058 women; mean ± SD body mass index (in kg/m 2 ): 31 ± 5] who attended outpatient obesity clinics were enrolled in the ONTIME (Obesity, Nutrigenetics, Timing, Mediterranean) study. Timing of food intake was estimated with a validated questionnaire. Anthropometric variables and PLIN1 genotypes were analyzed, including 6209T>C (rs2289487), 11482G>A (rs894160), 13041A>G (rs2304795), and 14995A>T (rs1052700). The main outcomes were effectiveness of the program and weight-loss progression during 28 wk of treatment. The PLIN1 locus was associated with variability in response to a weight-loss program. Specifically, carrying the minor C allele at the PLIN1 6209T>C was associated with better weight-loss response (P = 0.035). The probability of being a better responder [percentage of weight loss ≥7.5% (median)] was 33% higher among C than among TT carriers (OR: 1.32; 95% CI: 1.05, 1.67; P = 0.017). We found an interaction of PLIN1 × food timing between the 14995A>T variant and timing of lunch eating for total weight loss (P = 0.035). Among AA carriers, eating late was associated with less weight loss (P < 0.001), whereas time of eating did not influence weight loss among TT carriers (P = 0.326). Variability at the PLIN1 locus is associated with variability in weight loss. Moreover, eating late is related to lower weight-loss effectiveness among carriers of the AA genotype at the PLIN1 14995A>T variant. These results contribute to our ability to implement more precise and successful obesity treatments. The ONTIME study was registered at clinicaltrials.gov as NCT02829619. © 2016 American Society for Nutrition.

Using mHealth Technology to Enhance Self-Monitoring for Weight Loss A Randomized Trial

PubMed Central

Burke, Lora E.; Styn, Mindi A.; Sereika, Susan M.; Conroy, Molly B.; Ye, Lei; Glanz, Karen; Sevick, Mary Ann; Ewing, Linda J.

2012-01-01

Background Self-monitoring for weight loss has traditionally been performed with paper diaries. Technologic advances could reduce the burden of self-monitoring and provide feedback to enhance adherence. Purpose To determine if self-monitoring diet using a PDA only or the PDA with daily tailored feedback (PDA+FB), was superior to using a paper diary on weight loss and maintenance. Design The Self-Monitoring and Recording Using Technology (SMART) Trial was a 24-month RCCT; participants were randomly assigned to one of three self-monitoring groups. Setting/participants From 2006 to 2008, 210 overweight/obese adults (84.8% female, 78.1% white) were recruited from the community. Data were analyzed in 2011. Intervention Participants received standard behavioral treatment for weight loss which included dietary and physical activity goals, encouraged the use of self-monitoring, and was delivered in group sessions. Main outcome measures Percentage weight change at 24 months, adherence to self-monitoring over time. Results Study retention was 85.6%. The mean percentage weight loss at 24 months was not different among groups (paper diary: −1.94% [95% CI= −3.88, 0.01], PDA: −1.38% [95% CI= – 3.38, 0.62], PDA+FB: –2.32% [95% CI= –4.29, −0.35]); only the PDA+FB group (p=0.02) demonstrated a significant loss. For adherence to self-monitoring, there was a time-by-treatment group interaction between the combined PDA groups and the paper diary group (p=0.03) but no difference between PDA and PDA+FB groups (p=0.49). Across all groups, weight loss was greater for those who were adherent ≥60% versus <30% of the time, p<0.001. Conclusions PDA+FB use resulted in a small weight loss at 24 months; PDA use resulted in greater adherence to dietary self-monitoring over time. However, for sustained weight loss, adherence to self-monitoring is more important than the method used to self-monitor. A daily feedback message delivered remotely enhanced adherence and improved weight loss, which suggests that technology can play a role in improving weight loss. PMID:22704741

Weight reduction in schizophrenics by molindone.

PubMed

Gardos, G; Cole, J O

1977-03-01

The weight-reducing property of molindone, a recently introduced antipsychotic drug, was tested in 9 hospitalized chronic schizophrenic patients. There was an average weight loss of 7.6 kg after 3 months on molindone; most of the loss occurred during the first month. The mechanism producing this weight loss is uncertain, but a central anorexigenic effect may be an important factor.

Understanding the Journey: A Phenomenological Study of College Students' Lived Experiences during the Weight-Loss Process

ERIC Educational Resources Information Center

Davis, Michael W.

2013-01-01

Although numerous studies have focused on understanding various aspects of the science of weight loss and weight gain in college students, understanding how the weight-loss process affects college students psychologically and behaviorally may help administrators and student affairs professionals to better work with students on their campuses. The…

Lorcaserin plus lifestyle modification for weight loss maintenance: Rationale and design for a randomized controlled trial.

PubMed

Tronieri, Jena Shaw; Alfaris, Nasreen; Chao, Ariana M; Pearl, Rebecca L; Alamuddin, Naji; Bakizada, Zayna M; Berkowitz, Robert I; Wadden, Thomas A

2017-08-01

Few studies have examined the efficacy of recently approved medications for chronic weight management in facilitating the maintenance of lost weight. This paper provides an overview of the design and rationale for a trial investigating whether lorcaserin, when combined with behavioral weight loss maintenance sessions (WLM), will facilitate the maintenance of losses of ≥5% of initial weight. In this two-phase trial, participants with obesity will enroll in a 14-week run-in diet program consisting of weekly group lifestyle modification sessions and a 1000-1200kcal/d meal replacement diet. Participants who complete this weight induction phase and lose at least 5% of initial weight will then be randomized to 52weeks of WLM plus lorcaserin or WLM plus placebo. We hypothesize that at 52weeks post randomization, participants assigned to WLM plus lorcaserin will achieve significantly better maintenance of the prior 5% weight loss. We will recruit 182 adults with obesity to participate in the diet run-in, 136 of whom (75%) are expected to become eligible for the randomized controlled trial. Co-primary outcomes include the percentage of participants who maintain a loss of at least 5% of initial weight at week 52 and change in weight (kg) from randomization to week 52. This two-phase design will allow us to determine the potential efficacy of chronic weight management using lorcaserin for maintaining initial losses of at least 5% body weight, induced by the use of a structured meal-replacement diet. This combined approach holds promise of achieving larger long-term weight losses. NCT02388568 on ClinicalTrials.gov. Copyright © 2017 Elsevier Inc. All rights reserved.

Outcomes associated with preoperative weight loss after laparoscopic Roux-en-Y gastric bypass

PubMed Central

Blackledge, Camille; Graham, Laura A.; Gullick, Allison A.; Richman, Joshua; Stahl, Richard; Grams, Jayleen

2016-01-01

Background Laparoscopic Roux-en-Y gastric bypass (LRYGB) is an effective treatment for achieving and maintaining weight loss and for improving obesity-related comorbidities. As part of the approval process for bariatric surgery, many insurance companies require patients to have documented recent participation in a supervised weight loss program. The goal of this study was to evaluate the relationship of preoperative weight changes with outcomes following LRYGB. Methods A retrospective review was conducted of adult patients undergoing LRYGB between 2008 and 2012 at a single institution. Patients were stratified into quartiles based on % excess weight gain (0–4.99 % and ≥5 % EWG) and % excess weight loss (0–4.99 % and ≥5 % EWL). Generalized linear models were used to examine differences in postoperative weight outcomes at 6, 12, and 24 months. Covariates included in the final adjusted models were determined using backwards stepwise selection. Results Of the 300 patients included in the study, there were no significant demographic differences among the quartiles. However, there was an increased time to operation for patients who gained or lost ≥5 % excess body weight (p < 0.001). Although there was no statistical significance in postoperative complications, there was a higher rate of complications in patients with ≥5 % EWG compared to those with ≥5 % EWL (12.5 vs. 4.8 %, respectively; p = 0.29). Unadjusted and adjusted generalized linear models showed no statistically significant association between preoperative % excess weight change and weight loss outcomes at 24 months. Conclusion Patients with the greatest % preoperative excess weight change had the longest intervals from initial visit to operation. No significant differences were seen in perioperative and postoperative outcomes. This study suggests preoperative weight loss requirements may delay the time to operation without improving postoperative outcomes or weight loss. PMID:26969666

Weight Loss at a Cost: Implications of High-Protein, Low- Carbohydrate Diets.

ERIC Educational Resources Information Center

Gabel, Kathe A.; Lund, Robin J.

2002-01-01

Addresses three claims of high-protein, low-carbohydrate diets: weight loss is attributed to the composition of the diet; insulin promotes the storage of fat, thereby, by limiting carbohydrates, dieters will decrease levels of insulin and body fat; and weight loss is the result of fat loss. The paper examines relevant scientific reports and notes…

Depression and Smoking

MedlinePlus

... Quit Stress & Mood Stress & Mood Smoking & Mood Stress Depression Anger Weight Management Weight Management Smoking and Weight Healthy Weight Loss Being Comfortable in Your Own Skin Your Weight Loss Expectations & Goals Healthier Lifestyle ... » Depression Basics » Depression and Smoking Depression and Smoking Why ...

Investigation of arterial gas occlusions. [effect of noncondensable gases on high performance heat pipes

NASA Technical Reports Server (NTRS)

Saaski, E. W.

1974-01-01

The effect of noncondensable gases on high-performance arterial heat pipes was investigated both analytically and experimentally. Models have been generated which characterize the dissolution of gases in condensate, and the diffusional loss of dissolved gases from condensate in arterial flow. These processes, and others, were used to postulate stability criteria for arterial heat pipes under isothermal and non-isothermal condensate flow conditions. A rigorous second-order gas-loaded heat pipe model, incorporating axial conduction and one-dimensional vapor transport, was produced and used for thermal and gas studies. A Freon-22 (CHCIF2) heat pipe was used with helium and xenon to validate modeling. With helium, experimental data compared well with theory. Unusual gas-control effects with xenon were attributed to high solubility.

A pilot study comparing two weight loss maintenance interventions among low-income, mid-life women

PubMed Central

2013-01-01

Background Despite high obesity prevalence rates, few low-income midlife women participate in weight loss maintenance trials. This pilot study aims to assess the effectiveness of two weight loss maintenance interventions in this under-represented population. Methods Low-income midlife women who completed a 16-week weight loss intervention and lost ≥ 8 lbs (3.6 kg) were eligible to enroll in one of two 12-month maintenance programs. The programs were similar in content and had the same number of total contacts, but were different in the contact modality (Phone + Face-to-Face vs. Face-to-Face Only). Two criteria were used to assess successful weight loss maintenance at 12 months: (1) retaining a loss of ≥ 5% of body weight from the start of the weight loss phase and (2) a change in body weight of < 3%, from the start to the end of the maintenance program. Outcome measures of changes in physiologic and psychosocial factors, and evaluations of process measures and program acceptability (measured at 12 months) are also reported. For categorical variables, likelihood ratio or Fisher’s Exact (for small samples) tests were used to evaluate statistically significant relationships; for continuous variables, t-tests or their equivalents were used to assess differences between means and also to identify correlates of weight loss maintenance. Results Overall, during the 12-month maintenance period, 41% (24/58) of participants maintained a loss of ≥ 5% of initial weight and 43% (25/58) had a <3% change in weight. None of the comparisons between the two maintenance programs were statistically significant. However, improvements in blood pressure and dietary behaviors remained significant at the end of the 12-month maintenance period for participants in both programs. Participant attendance and acceptability were high for both programs. Conclusions The effectiveness of two pilot 12-month maintenance interventions provides support for further research in weight loss maintenance among high-risk, low-income women. Trial registration ClinicalTrials.gov Identifier: NCT00288301 PMID:23855318

Smartloss: A Personalized Mobile Health Intervention for Weight Management and Health Promotion

PubMed Central

Gilmore, L. Anne; Apolzan, John W; Myers, Candice A; Thomas, Diana M

2016-01-01

Background Synonymous with increased use of mobile phones has been the development of mobile health (mHealth) technology for improving health, including weight management. Behavior change theory (eg, the theory of planned behavior) can be effectively encapsulated into mobile phone-based health improvement programs, which is fostered by the ability of mobile phones and related devices to collect and transmit objective data in near real time and for health care or research professionals and clients to communicate easily. Objective To describe SmartLoss, a semiautomated mHealth platform for weight loss. Methods We developed and validated a dynamic energy balance model that determines the amount of weight an individual will lose over time if they are adherent to an energy intake prescription. This model was incorporated into computer code that enables adherence to a prescribed caloric prescription determined from the change in body weight of the individual. Data from the individual are then used to guide personalized recommendations regarding weight loss and behavior change via a semiautomated mHealth platform called SmartLoss, which consists of 2 elements: (1) a clinician dashboard and (2) a mobile phone app. SmartLoss includes and interfaces with a network-connected bathroom scale and a Bluetooth-connected accelerometer, which enables automated collection of client information (eg, body weight change and physical activity patterns), as well as the systematic delivery of preplanned health materials and automated feedback that is based on client data and is designed to foster prolonged adherence with body weight, diet, and exercise goals. The clinician dashboard allows for efficient remote monitoring of all clients simultaneously, which may further increase adherence, personalization of treatment, treatment fidelity, and efficacy. Results Evidence of the efficacy of the SmartLoss approach has been reported previously. The present report provides a thorough description of the SmartLoss Virtual Weight Management Suite, a professionally programmed platform that facilitates treatment fidelity and the ability to customize interventions and disseminate them widely. Conclusions SmartLoss functions as a virtual weight management clinic that relies upon empirical weight loss research and behavioral theory to promote behavior change and weight loss. PMID:26983937