Background: Three-dimensional optical (3DO) body composition (BC) from statistical shape models have been developed and vali- dated on cross-sectional data. This technique has shown to be ac- curate ...and precise in respect to dual-energy X-ray absorptiometry (DXA). However, it is unknown if 3DO is sensitive enough to detect change in BC. Therefore, our objective was to evaluate the accuracy of the previously developed cross-sectional models for detecting change and the need for new longitudinal models. Methods: Data from participants in the longitudinal arm of the Shape Up! Adults, FB4 Study, and Louisiana State University Athlete's Study were used in this analysis. Measures on all partici- pants included 3DO and DXA scans at baseline and follow-up using similar make and model systems. Healthy participants went through study-specific interventions that included either dietary or physical activity modifications. Fat mass (FM) and visceral adipose tissue (VAT) were estimated from 3DO scans using previously-developed statistical shape models. Changes in these estimates were compared to criterion changes in DXA. Further, fundamental studies relating change in shape and demographics to DXA were performed using step-forward linear regression with 5-fold cross-validation. Results: For this analysis, 107 participants completed the study (males = 67). Of the models created, 3DO estimates of FM from the previ- ously developed cross-sectional model performed the best for females (R2 = 0.88, RMSE = 1.29 kg) while fundamental models of change in shape were best for males (R2 = 0.88, RMSE = 1.8 kg). Change in DXA VAT for both males and females was best predicted by change in shape models (R2 = 0.57 and 0.49, RMSE = 85 g and 76 g, respectively). Conclusions: Using a diverse population of healthy males and females, various 3DO models accurately estimated changes in DXA FM and VAT over time.
Background: Body composition is an important metric for evaluating metabolic health. The InBody (IB) 720 and the portable and more affordable InBody 230 (InBody, Seoul, South Korea) are ...multifrequency bioelectrical impedance analysis (BIA) devices used to estimate body composition. The gold standard for estimating lean mass and fat mass is dual-energy X-ray absorption (DXA), and the gold standard for body water is isotope dilution with deuterium oxide (D2O). However, the gold standards are more expensive and require technically-trained personnel. Hence, we set out to see if BIA devices can match the standards. Methods: Forty-five women (21.56±2.82 years; BMI 26.71±6.39; 27.6% Caucasian) were evaluated using the IB720, IB230, DXA, and D2O for total body water (TBW), lean body mass (LBM), and total fat mass (TFM). Validity and agreement were determined by correlation statistics and Bland-Altman plots of differences between measures versus mean. Results: Both LBM and TFM were strongly correlated between the BIA devices and DXA, as were TBW measures by D2O and the BIA devices (r>0.90, p<0.05 for all). Bland-Altman plots indicated that TBW measures by both BIA devices and D2O were in agreement, while LBM and TFM measures by both BIA devices and DXA were not in agreement. Conclusions: Our findings suggest that the IB720 and IB230 can be used in place of D2O method to measure TBW; however, they cannot be used in place of DXA for fat mass and regional lean mass. The IB720 and IB230 were in agreement and can be used interchangeably for TBW and TFM.
Background: Previous studies have shown that lipid accumulation in the liver, as seen in obese individuals, is associated with depolarization of hepatocytes. Hepatocyte depolarization has been shown ...to cause changes in hepatic vagal afferent nerve (HVAN) firing rate, a key component in food intake regulation. However, it is not well understood how hyperpolarization of hepatocytes impacts energy homeostasis. In this study, we assessed the impact of chronic hyperpolarization, through the overexpression of potassium inward rectifying channel 2.1 (KCNJ2) in hepatocytes on basal energy expenditure (EE) in thermoneutral housing temperatures. Methods: Male C57Bl/6J were placed on a low-fat diet and given either AAV-TBG-GFP or AAV-TBG-KCNJ2 intraperitoneal injections. 6-weeks post injection mice were placed in an indirect calorimetry system and energy expenditure, body weight, body composition, and food intake were recorded over 1-week. Results: There was no significant difference in body weight, body composition, or food intake. Interestingly, total EE was significantly higher in KNCJ2 mice compared to GFP, which was driven by increased nonresting EE and not resting EE. As such, activity EE and cage activity was significantly greater in the KCNJ2 mice. Additionally, there was no significant difference in the respiratory quotient or the thermic effect of food. Concluslons: Together these data show that the hyperpolarization of hepatocytes results in increased activity and total EE and shows that hepatocyte polarization is an important factor in energy homeostasis and merits further investigation.
Background: Temporal increases in energy intake over time have been implicated as the cause of the worsening epidemic of obesity but are difficult to examine due to limitations in energy intake ...assessments. In an ad libitum energy intake model, we examined longitudinal and seasonal differences in energy intake over 20 years. Methods: Participants (n=292; 59% Indigenous Americans; 61% male; BMI (mean ± SD) 31.6 ± 8 kg.m2) were admitted for a 10 day inpatient stay during which measurements such as body composition (by DXA), 24 hour energy expenditure including spontaneous physical activity (SPAVS(1 ) otherwise known as fidgeting, and ad libitum energy intake over 3 days using a validated vending machine paradigm were collected. General linear models (GLM) were used for secular and seasonal trends adjusting for sex, age, FFM-index, FMindex, and race. FFM-index and FM-index consider height to normalize body composition. SPA was also added to these models in later analysis. Results: Total energy intake (kcal) (B= -411), percent weight maintaining energy needs (%WMEN) (B= -15), and fat kcals (B= -197) were lower (p<0.05) in the summer compared to winter but these differences were attenuated after adjustment for SPA (all p>0.11). KJ (1 As expected FFM-index was positively associated with all food intake measures (all p<0.05) while FM-index was negatively associated (all p<0.05). Adjusted models of secular trends, expressed in years, indicated total kcals (B= -55), %WMEN (B= -2), protein kcals (B= -10), fat kcals (B= -27), and carb kcals (B= -22) all decreased over time. SPA was positively associated with total energy intake (partial R: 0.21, p<0.0036), %WMEN (partial R: 0.18, p<0.01), protein kcals (partial R: 0.21, p<0.0032), fat kcals (partial R: 0.016, p<0.021), and carb kcals (partial R: 0.0020, p<0.0043) when included in above models. Secular trends in body composition measures revealed decreased FFM-index (partial R: -0.39, p<0.0001), but increased FM-index (partial R: 0.34, p<0.0001) with no changes in weight, BMI, and percent body fat (all p>0.20). Conclusions: Ad libitum intake and FFM-index are decreasing with time. FFM-index is the major determinant of energy demand, so its decline may play a role in overall reduction in intake.
Background: Relationships between depression and body weight have been reported. Knowledge about the influences of other mood states may inform interventions aimed at healthy weight management. ...Methods: Baseline data of the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (phase II) study (n=212, 21-50 years; 69% women; BMIs 22-27.9 kg/m2) was analyzed. Relationships between outcome measures %body fat and % fat-free mass (ffm) (fat or ffm/weight {kg}), derived from dualenergy X-ray absorptiometry, and Profile of Mood States (POMS) (total mood disturbance scores; tension, depression, anger, vigor, fatigue, confusion subscales) were assessed using correlation (Pearson) and multiple linear regression. Covariates included sex, age, family income (>$100,000/$80-99,999/$60-79,999/ $40-59,999/s$39,000 US), education (doctorate/non-doctoral graduate degree/some post-secondary/college graduate/sgrade 12), relationship status (married/not married and living with partner/ single and never married/previously married), physical activity (METs), and macronutrient intakes (% total calories). Results: Mean body composition measures were 33.0±6.3% (%body fat) and 67.1±6.3% (%ffm). Correlations were found between POMS anger score and %body fat (r=-0.19) as well as %ffm (r=0.20) (p's<0.05). Regression analysis results for each component of the POMS found no significant associations. The covariates %fat intake, sex, and physical activity were commonly associated with %ffm and % body fat (p's<0.05). When all subscales were included in the model, % ffm was associated with vigor (b=0.12), sex (b=-10.4), and %fat intakes (b=-0.21) (p's<0.05). %body fat was associated with sex (b=10.3) and %fat intakes (b=0.21) (p's<0.05). Conclusions: When compared to mood states, sex, fat intake, and physical activity appear to be stronger predictors of body composition. Continued investigations of the inter-relationships among mood states, sex, dietary intake, physical activity, and body composition may lead to more precise healthy weight management interventions.
Background: Nutrition bars are perceived by consumers as a convenient and healthy snack option; yet there is little research examining health outcomes associated with snack bar ingestion. This ...research examined the impact of the daily ingestion of commercial high protein nutrition bars (with or without added fiber) on 24-h energy intake and body composition after one week among young, free-living healthy adults. Methods: In a 4-week double-blind, randomized crossover trial, 21 nonsmoking, non-athlete adults (15 females; 21.9±2.6 y; 23.9±2.7 kg/m2) were randomly assigned to HP (high protein: 21 g protein, 15 g carbohydrate, 5 g fat) or HPHF (high protein high fiber: 20g protein, 14 g fiber, 10 g carbohydrate, 7 g fat) groups. Bars were consumed daily during trial weeks 2 and 4 (crossover fashion) within an hour of waking. Body composition was measured using bioelectrical impedance at baseline and the end of each feeding period. Dietary data (using the MyfitnessPal app) was measured on three nonconsecutive days each week of the trial. Results: The mean energy intakes for the weeks the bars were consumed were significantly elevated versus the baseline or washout weeks (+126-220 kcal, p = 0.022, repeated measures ANOVA). Mean fat mass following one week of HP or HPHF bar consumption was elevated versus baseline value (18.8+6.8, 18.8+6.8 and 18.3 ± 6.7 kg respectively; p = 0.039). Physical activity level at baseline was weakly related to energy intake on the weeks the protein bars were consumed (r>0.330). Macronutrient intakes differed significantly between timepoints mirroring the nutrient profile for each bar. Conclusions: Sales of nutrition bars show rapid growth year after year in the U.S. and may represent an efficient source of specific nutrients. However, ingestion of nutrition bars may increase total daily energy intake and the risk of gaining fat mass and eventual body mass over time.
Background: Body composition provides important information about individual risk for chronic disease. Dual Energy X-ray Absorptiometry (DXA) and isotopic dilution technique using deuterium oxide ...(D2O) are widely accepted as the gold standard methods for estimating total fat mass and total body water (TBW), respectively. Both methods are expensive and require trained personnel for execution. Bioelectrical impedance analyzers (BIAs) like InBody 770 (IB770) which use a low-frequency electrical current to estimate total body water, regional and total body fat and lean mass. The objective of this study was to test and report the validity of research grade BIA, the IB770 body composition measures against the cold standard techniques. Methods: Fifty-five women (21.1±2.6 years, BMI: 25.8±5.5 kg/m2, 40% African American) were evaluated using IB770, DXA, and D2O. Measures of TBW, regional (arms, trunk, and legs) and total fat masses (TFM), and regional and total lean body masses (LBM) were calculated. Correlation analysis was used to verify body composition measures between devices. Agreement was determined by examining relationships between the differences in and averaged body composition measured on each method. Results: TBW measured by the IB770 and D2O were correlated (p=0.97; p<0.001). We also found positive correlations for measurements of LBM (p=0.97; p<0.001), TFM (p=0.99; p<0.001), regional fat mass of arms (p=0.95; p<0.001), legs (p=0.91; p<0.001), and trunk (p=0.98; p<0.001) when measured by IB770 and DXA. Arms, trunk, and legs lean masses measured by IB770 and DXA were not associated (p>0.05). The lack of a significant relationship between the difference and average TBW measured by IB770 and D20 (p=-0.07; p=0.608) indicates a good agreement between the two. The relationship between the difference and average total lean body mass (p=0.13; p=0.348) and trunk fat mass (p =0.01; p=0.935) did not differ using IB770 and DXA, indicating that these are devices are in agreement. Significant differences were found in the relationship between the difference and average for total, arms and legs fat masses measured by IB770 and DXA, showing that these are devices are not in agreement for these body composition measures. Conclusions: IB770 showed agreement with D2O and can be used interchangeably for TBW. IB770 can also be used in place of DXA for lean body mass and trunk fat mass.
El propósito de este estudio fue investigar la relación de la composición corporal y las variables bioquímicas con el POC, así como observar la tendencia de la heredabilidad. Estudio transversal con ...gemelos monocigóticos y dicigóticos adultos. Para obtener los valores del POC, la prueba de ejercicio cardiopulmonar fue realizada se realizó un protocolo con sobre cinta rodante. Para la composición corporal, se utilizaron laabsorciometríade energía dual y la antropometría. Para las inferencias, se realizaron la concordancia de Spearman y la prueba de hipótesisMann-Whitney.Los resultados mostraron que lasvariables de composición corporal no se correlacionaron significativamente con el punto óptimo cardiorrespiratorio. El Punto Óptimo Cardiorrespiratorio y las variables bioquímicas en general demostraron una mayor tendencia a ser influenciados por factores ambientales. El comportamiento de las variables de composición corporal demostró una mayor influencia de la heredabilidad.
Background: Evaluating body composition and anthropometry in children is vital in developing nutritional programs and health assessments. Recent advancements in three-dimensional optical (3DO) ...imaging have made this technology ubiquitous in fitness centers and clinical settings across the worldversatile for body composition and tracking health outcomes in adults. . Advanced statistical methods have been used to calculate automated anthropometry and convert body shape into accurate and precise measures of composition. However, the stability and reproducibility of these 3DO imaging systems have not been previously evaluated in children. In this study, we investigate the short-term precision and longitudinal stability of a 3DO imaging system over time. Methods: A three-year old mannequin covered in a creme jersey fabric underwent multiple whole body 3DO scans (3DMD, GA) in the span of two weeks. To monitor short-term precision, ten scans were acquired one day with repositioning and longitudinal stability equipment was monitored by scanning the phantom twice per day for 10 days with repositioning. The mannequin was repositioned after each scan. 3DO scans were spatially registered to each other using a templating method to coregister all scan vertices. SizeStream Studio v5.2.9 was used to provide automated anthropometry: height, waist circumference (WC), hip circumference (HC), and right and left thigh circumferences (RTC and LTC, respectively). Stepwise regression was performed to create equations. Previously developed pediatric body composition models were used to predict total fat mass (FM). Precision error of all variables was quantified as RMSE (%CV). Results: For this analysis 30 scans (10 from day 1) were availableMeasurement precision of all variables were quantified using RMSE and %CV expressed as a percentage. The short- term precision of anthropometry ranged from RMSE = 0.14 - 0.16 cm (0.16 - 0.54 %CV). to CV = 0.54% RMSE = 0.16cm and FM precision was RMSE = 0.55 kg (2.1 %CV)was. There was no statistically significant change in the mean values over the 10-day period (i.e. slope = 0, R2 = 0, p > 0.05). Conclusions: Pediatric anthropometry and body composition measurements from 3DO systems are reliable with high precision. Childlike phantoms may be a useful way to monitoring the stability and performance of these systems.
