Estimate Body Composition Research Articles

High precision but systematic offset in a standing bioelectrical impedance analysis (BIA) compared with dual-energy X-ray absorptiometry (DXA)

Bioelectrical impedance analysis (BIA) provides a practical method of body composition estimation for field research and weight management programmes, with devices and algorithms that have improved in recent years. We...

Associations between visceral adipose tissue estimates produced by near-infrared spectroscopy, mobile anthropometrics, and traditional body composition assessments and estimates derived from dual-energy X-ray absorptiometry.

Assessments of visceral adipose tissue (VAT) are critical in preventing metabolic disorders; however, there are limited measurement methods that are accurate and accessible for VAT. The purpose of this cross-sectional study was to evaluate the association between VAT estimates from consumer-grade devices and traditional anthropometrics and VAT and subcutaneous adipose tissue (SAT) from dual-energy X-ray absorptiometry (DXA). Data were collected from 182 participants (female = 114; White = 127; Black/African-American (BAA) = 48) which included anthropometrics and indices of VAT produced by near-infrared reactance spectroscopy (NIRS), visual body composition (VBC) and multifrequency BIA (MFBIA). VAT and SAT were collected using DXA. Bivariate and partial correlations were calculated between DXAVAT and DXASAT and other VAT estimates. All VAT indices had positive moderate-strong correlations with VAT (all P < 0·001) and SAT (all P < 0·001). Only waist:hip (r = 0·69), VATVBC (r = 0·84), and VATMFBIA (r = 0·86) had stronger associations with VAT than SAT (P < 0·001). Partial associations between VATVBC and VATMFBIA were only stronger for VAT than SAT in White participants (r = 0·67, P < 0·001) but not female, male, or BAA participants individually. Partial correlations for waist:hip were stronger for VAT than SAT, but only for male (r = 0·40, P < 0·010) or White participants (r = 0·48, P < 0·001). NIRS was amongst the weakest predictors of VAT which was highest in male participants (r = 0·39, P < 0·010) but non-existent in BAA participants (r = -0·02, P > 0·050) after adjusting for SAT. Both anthropometric and consumer-grade VAT indices are consistently better predictors of SAT than VAT. These data highlight the need for a standardised, but convenient, VAT estimation protocol that can account for the relationship between SAT and VAT that differs by sex/race.

The impact of an early intervention home-based program on body composition in preterm-born preschoolers with very low birth weight.

Early child interventions focused on the family prevented neurodevelopmental and behavioral delays and can provide more knowledge regarding responsive feeding, thus creating learning opportunities to promote better quality nutrition and preventing failure to thrive. The aim is to verify the impact of a continuous program of early home-based intervention on the body composition of preschool infants who were born preterm with very low birth weight (VLBW). This is a longitudinal analysis from a randomized controlled trial, including VLBW preterm children, born in a tertiary hospital in Southern Brazil and followed up at the high-risk institutional ambulatory clinic. Participants were divided into the intervention group (IG): skin-to-skin care with the mother (kangaroo care), breastfeeding policy, and tactile-kinesthetic stimulation by mothers until hospital discharge. Subsequently, they received a program of early intervention with orientation and a total of 10 home visits, independently from the standard evaluation and care that was performed following the 18 months after birth; conventional group (CG): standard care according to the routine of the newborn intensive care unit (NICU), which includes kangaroo care, and attending to their needs in the follow-up program. Body composition estimation was performed using bioelectrical impedance analyses (BIA), and physical activity and feeding practices questionnaires were evaluated at preschool age, as well as anthropometric measurements and biochemical analysis. Data of 41 children at 4.6 ± 0.5 years old were evaluated (CG n = 21 and IG n = 20). Body weight, height, body mass index, waist and arm circumferences, and triceps and subscapular skinfold did not differ between groups. The IG presented higher segmented fat-free mass (FFM) when compared to the CG (right arm FFM: 0.74 vs. 0.65 kg, p = 0.040; trunk FFM: 6.86 vs. 6.09 kg, p = 0.04; right leg FFM: 1.91 vs. 1.73 kg, p = 0.063). Interaction analyses showed that segmented FFM and FFM Index were associated with higher iron content in the IG. In the CG, interaction analyses showed that increased visceral fat area was associated with higher insulin resistance index. An early intervention protocol from NICU to a home-based program performed by the mothers of VLBW preterm children of low-income families presents a small effect on FFM.

P.59 Associations between body composition estimates and motor function in ambulatory individuals with Duchenne muscular dystrophy

The heterogeneity of functional decline observed in individuals with Duchenne muscular dystrophy (DMD) presents a long-standing challenge to optimizing clinical care and implementing clinical trials. Ongoing efforts to identify biomarkers and predictors of disease progression may help improve accuracy of prognosis to ameliorate these challenges. The relationship between body composition and motor performance in individuals with DMD has been explored using several estimation methods. Although Body Mass Index (BMI) is a feasible estimate of body composition, it is confounded by the short stature of corticosteroid treated patients. Estimation methods utilizing imaging, techniques, such as dual energy x-ray absorptiometry (DXA) and magnetic resonance imaging (MRI), have shown promise as biomarkers of disease progression. One DXA-based estimation method is appendicular lean mass index (ALMI), the total lean mass in arms and legs divided by height in meters squared, is significantly decreased in children with DMD compared to healthy controls. The relationship between ALMI and motor performance across age has not been well studied. This study will compare the association of body composition estimates (BMI / ALMI) to change in motor outcomes, including the North Star Ambulatory Assessment and Timed Rise from Supine, across childhood using a longitudinal natural history dataset. The sample includes 100+ individuals and 275 unique observations in children with DMD aged 3 -14 years. Preliminary analyses with 97 individuals and 263 observations found ALMI values in the top quartile was associated with a 1 second faster Timed Rise from Supine compared to ALMI values in the bottom quartile with age and corticosteroid treatment duration controlled, p < .001 (-.67, -1.33). Established correlates of motor function, including corticosteroid dose and ankle range of motion, will be included as covariates.

Visual body composition assessment methods: A 4-compartment model comparison of smartphone-based artificial intelligence for body composition estimation in healthy adults

Visual body composition (VBC) estimates produced from smartphone-based artificial intelligence represent a user-friendly and convenient way to automate body composition remotely and without the inherent geographical and monetary restrictions of other body composition methods. However, there are limited studies that have assessed the reliability and agreement of this method and thus, the aim of this study was to evaluate VBC estimates compared to a 4-compartment (4C) criterion model. A variety of body composition assessments were conducted across 184 healthy adult participants (114F, 70M) including dual-energy X-ray absorptiometry and bioimpedance spectroscopy for utilization in the 4C model and automated assessments produced from two smartphone applications (Amazon Halo®, HALO; and myBVI®) using either Apple® or Samsung® phones. Body composition components were compared to a 4C model using equivalence testing, root mean square error (RMSE), and Bland-Altman analysis. Separate analyses by sex and racial/ethnic groups were conducted. Precision metrics were conducted for 183 participants using intraclass correlation coefficients (ICC), root mean squared coefficients of variation (RMS-%CV) and precision error (PE). Only %fat produced from HALO devices demonstrated equivalence with the 4C model although mean differences for HALO were <±1.0kg for FM and FFM. RMSEs ranged from 3.9% to 6.2% for %fat and 3.1-5.2kg for FM and FFM. Proportional bias was apparent for %fat across all VBC applications but varied for FM and FFM. Validity metrics by sex and specific racial/ethnic groups varied across applications. All VBC applications were reliable for %fat, fat mass (FM), and fat-free mass (FFM) with ICCs ≥0.99, RMS-%CV between 0.7% and 4.3%, and PEs between 0.3% and 0.6% for %fat and 0.2-0.5kg for FM and FFM including assessments between smartphone types. Smartphone-based VBC estimates produce reliable body composition estimates but their equivalence with a 4C model varies by the body composition component being estimated and the VBC being employed. VBC estimates produced by HALO appear to have the lowest error, but proportional bias and estimates by sex and race vary across applications.

Development and Validation of a Novel Waist Girth-Based Equation to Estimate Fat Mass in Young Colombian Elite Athletes (F20CA Equation): A STROSA-Based Study.

The estimation of body fat percentage (%BF) from anthropometry-related data requires population-specific equations to avoid incorrect interpretations in young athletes. Waist girth (WG) has been described as potential predictor of fat mass (FM) in several populations; however, there are no valid WG-based equations to estimate body composition in young Colombian athletes. The aim of this STandardisierte BerichtsROutine für Sekundärdaten Analysen STROSA-based study was twofold: i) to validate the relative fat mass (RFM) and its pediatric version (RFMp) compared to dual-energy x-ray absorptiometry (DXA) and ii) to develop a new equation (F20CA) to estimate the fat mass in Colombian children and adolescent elite athletes. A total of 114 young athletes that belong to the ‘Team Medellín’ program (58F, 56M; 51 children, 63 adolescents; 14.85 [2.38] years; 55.09 [12.16] kg; 162.38 [11.53] cm) participated in this cross-sectional study. The statistical analysis revealed a poor correlation, agreement and concordance of RFMp and RFM estimations with DXA measurements. After model specification using both Ordinary Least Square method and Bayesian analysis, the regression output revealed that sex, body mass-to-waist ratio, and waist-to-stature ratio were the statistically significant predictor variables that account for variability in FM. The new F20CA equation is expressed as FM (kg) = 5.46 ∗ (Sex) + 0.21 ∗ (BM/W [kg/m]) + 81.7 ∗ (W/Stature [cm/cm]) − 41.8 (R2 = 0.683; SEE = 2.468 kg), where sex is 0 for males and 1 for females. A moderate-to-high correlation and agreement of the F20CA was confirmed within the internal validation data set (R2 = 0.689; ICC [95%CI] = 0.805 [0.615, 0.904]; RMSE = 2.613 kg). The Bland–Altman analysis corroborated the high concordance between the reference method (DXA) and the F20CA-estimated FM (bias [95% LoA] = 1.02 [−3.77, 5.81] kg), indicating the two methods could be considered interchangeable. Even though external validation is needed, practitioners are advised to use the F20CA in young Colombian athletes with similar characteristics to those who participated in this study.

Clinicopathological and Body Composition Analysis of VHL and TTN Gene Mutations in Clear Cell Renal Cell Carcinoma: An Exploratory Study

Background: The Cancer Genome Atlas (TCGA) Research Network revealed numerous clear cell renal cell carcinoma (ccRCC) gene mutations among which titin (TTN). The link between excessive amounts of visceral adipose tissue (VAT) and ccRCC pathogenesis is known. A relationship between VHL and TTN gene mutations and a CT-derived estimation of body composition in ccRCC patients has been evaluated. Methods: We retrospectively assessed patients from the TCGA-kidney renal clear cell carcinoma (KIRC) database for evaluation of clinicopathological and body composition analysis of ccRCC VHL and TTN gene mutations. Results: Gene expression levels and survival were assessed on a large cohort of 483 patients and 533 tumor samples. A statistically significant difference of VHL expression reduction in primary tumor (p &lt; 0.0001) and a TTN expression increase in primary tumor (p &lt; 0.0001) was shown. TTN high expression levels was associated with statistically significant lower KIRC patient survival at eight years (p &lt; 0.05). For body composition analysis, we included 54 male patients divided into two groups: ccRCC-VHL (n = 41) and ccRCC-TTN (n = 13) groups. Statistically significant differences between the two groups were obtained for total adipose tissue (TAT) (p &lt; 0.01), VAT (p &lt; 0.05), subcutaneous adipose tissue (SAT) (p &lt; 0.05) and total abdominal muscle (TAM) (p &lt; 0.05) areas. Conclusion: This study demonstrates a link between ccRCC TTN gene mutation and shorter patient survival. The reduction of the analyzed tissues might be a risk of cancer cachexia in ccRCC patients with TTN gene mutation.

PSII-A-7 Evaluation of Technician Skill Level Effect on Ultrasonic Estimates of Body Composition in Feedlot Heifers

Abstract The objective of this study was to evaluate technician skill level on ultrasonic estimates of body composition in feedlot heifers (n = 31) across different days. One unexperienced technician (UT1) and one experienced technician (UT2) took measurements of 12-13th rib fat thickness (FTU), longissimus muscle area (REAU) and intramuscular fat thickness (IMFU) on Day 1 (98 days preharvest), Day 2 (42 days preharvest) and Day 3 (48h preharvest) with an IBEX EVO II ultrasound unit equipped with 3.5-MHz, 172-mm scanning width, linear-array transducer. Carcass fat thickness (FTC), longissimus muscle area (REAC) and Marbling Score (MS) were measured 24 h postmortem. Significant differences were observed between FTC and FTU for UT1 (p&amp;lt; .01) and REAC and REAU for UT1 (p&amp;lt; .01) on Day 3. No differences were detected between FTC, FTU, REAC and REAU for UT2 on Day 3. No differences existed for REAU between technicians on Day 1 (p = 0.4547) or Day 2 (p = 0.4937). Significant differences between technicians were observed on Day 3 (p&amp;lt; .05) for REAU. Pearson correlation coefficients (p&amp;lt; .01) were .79 and .59 between REAU and REAC for UT1 and UT2, respectively. No significant differences were observed between technicians on Day 1 (p = 0.6175), Day 2 (p = 1.0) or Day 3 (p = 0.0625) for FTU. Pearson correlation coefficients (p&amp;lt; .01) were .79 and .76 between FTU and FTC for UT1 and UT2, respectively. No significant differences were observed between technicians on Day 1 (p = 0.1716) or Day 2 (p = 0.0595) but were significant on Day 3 (p &amp;lt; 0.05) for IMFU. Pearson correlation coefficients (p&amp;lt; .01) were .69 and .68 between IMFU and MS for UT1 and UT2, respectively. These results indicate dependence of ultrasound image collection on technician skill and years of experience to achieve accurate predictions for carcass endpoints in beef cattle.

PSIII-A-8 Daily Clenbuterol Administration to Lambs Born with low Birthweight due to Intrauterine Growth Restriction Recovered Growth Rates and Improved Body Composition at 60 D of age

Abstract Low birthweight due to intrauterine growth restriction (IUGR) results from unfavorable in utero conditions (i.e., hypoxemia, hypoglycemia) that impairs growth capacity for muscle and other tissues. This programming effect reduces growth efficiency in IUGR offspring below their genetic potential. Specific programming mechanisms are not known, but recent evidence indicates reduced β2 adrenergic regulation of IUGR muscle. Thus, our objective was to determine if early-life growth deficits in IUGR juvenile lambs are improved by manipulating β2 adrenergic activity with daily IM administration of the β2 agonist, clenbuterol (Clen), from birth to 60 d of age. Maternal heat stress-induced IUGR (n=10) and IUGR+Clen (n=9) lambs were smaller (P&amp;lt; 0.05) than controls (n=11) at birth, weighed 18% and 11% less (P&amp;lt; 0.05), respectively, than controls at 30 d of age, and weighed 16% and 13% less (P&amp;lt; 0.05), respectively, at 60 d of age. Average daily gain at 30 and 60 d of age was reduced (P≤0.05) for IUGR but not IUGR+Clen lambs compared to controls. Bioelectrical impedance analysis was used to estimate body composition in live lambs at 58 d of age. Estimated fat-free lean mass and estimated muscle mass were less (P≤0.05) for IUGR but not IUGR+Clen lambs compared to controls. Estimated protein and fat content as well as protein:fat were likewise reduced (P&amp;lt; 0.05) for IUGR but not IUGR+Clen lambs. At necropsy, whole hindlimbs tended to be lighter (P≤0.09) and flexor digitorum superficialis muscle was lighter (P&amp;lt; 0.05) for IUGR but not IUGR+Clen lambs compared to controls. Loin-eye areas measured in chilled carcasses were 15% smaller (P&amp;lt; 0.05) for IUGR lambs and 19% larger (P&amp;lt; 0.05) for IUGR+Clen lambs compared to controls. From this study, we conclude that poor postnatal growth and body composition observed in IUGR juvenile lambs was improved when clenbuterol was used to target programmed deficits in β2 adrenergic regulation of muscle.

327 Parameter Updates in the Davis Growth Model for Growth, Intake, and Composition of Modern Angus-Cross Cattle

Abstract The Davis Growth Model is a dynamic model used to estimate body composition and growth in beef cattle by simulating total body DNA and protein turnover. Since model development and parametrization in the 1980s, the model has been re-structured to account for previous rate of protein accretion and prior nutrition. Original parameter estimates for alpha (maintenance constant, where net energy for maintenance is alpha x shrunk body weight0.75; 0.08406) and K2 (protein synthesis rate constant; 0.0444) may not fit modern, heavier, more productive cattle. Angus-cross steers (n = 24; initial body weight 402 ± 12 kg) were fed using automated feed weight stations in group pens (8 steers/pen). Steers were fed a high energy ration twice daily, at 10% greater than the intake from the previous day. Steers were measured for hip height, body weight (BW), and ultrasonic measurements for ribeye area and back fat every 28 d until harvest (d 128). These measurements were used to calculate empty BW, empty body fat, and empty percent body fat for alpha and K2 estimates. Parameter estimates (± SD) were 0.12661 (0.01587) and 0.04919 (0.00220) for alpha and K2, respectively. Parameter estimates in the current study reflect a large increase in apparent maintenance. Maintenance requirements were moderately correlated with back fat thickness and feed conversion efficiency. Protein turnover had very strong correlations with ribeye area and feed conversion efficiency. Average feed conversion efficiency in the current study was 0.17. To evaluate parameter estimates, the model was re-run using the new values for alpha and K2. On average, the model underpredicted final empty body weight by 0.08 kg and empty body fat percent by 0.01%-units. Considering the relatively large variation among observed alpha values and the magnitude of increase compared with those previously reported, further research is required to determine an accurate alpha.

Assessment Of Laboratory Devices For Estimating Body Composition In A Hispanic Population

PURPOSE: To determine the agreement between dual-energy x-ray absorptiometry (DXA) and multi-frequency bioelectrical impedance analysis (BIA) for estimating body fat percentage (BF%), fat mass (FM), and fat-free mass (FFM) in a Hispanic population. METHODS: One-hundred eighty-one individuals (males: n = 84; females: n = 97) of Hispanic descent had body composition estimated via DXA and BIA. Participants completed all testing wearing compression gear and provided a urine sample to assess hydration status. Adequate hydration was considered at a urine specific gravity value <1.029. Agreement between DXA and MF-BIA BF%, FM, and FFM was assessed using Pearson correlations, linear regression, and Bland-Altman analyses. Analyses yielded the standard error of the estimate (SEE), constant error (CE), 95% limits of agreement (LOA), and proportional bias for the entire group and within sexes. RESULTS: For BF%, BIA displayed similar CE ± 95% LOA for the sample (-3.17 ± 5.45%), males (-3.2 ± 5.5%), and females (-3.2 ± 5.4%) compared to DXA. Correlation analyses indicated near-perfect associations (sample: r = 0.96, males: r = 0.93, and females: r = 0.93); however, a moderate proportional bias was present for females (r = 0.48). The sample (r = 0.22) and males (r = -0.04) had trivial-to-no proportional bias. Regarding FM, BIA exhibited CE ± 95% LOA values of -1.4 ± 4.2 kg for the sample, -1.9 ± 4.6 kg for males, and -0.9 ± 3.6 kg for females. All groups displayed near-perfect associations (sample: r = 0.99, males: r = 0.97, and females: r = 0.99), despite a strong proportional bias for females (r = 0.68) and moderate bias for the sample (r = 0.36). No proportional bias was observed for males (r = -0.02). For FFM, males demonstrated the largest CE ± 95% LOA (1.6 ± 4.6 kg), compared to the sample (1.2 ± 3.9 kg) and females (0.9 ± 3.4 kg) when BIA was compared to DXA. Near-perfect associations were observed for all groups (sample: r = 0.98; males: r = 0.97; females: r = 0.97). No proportional biases existed for the sample (r = -0.01) or males (r = -0.10); however, females exhibited a moderate, negative bias (r = -0.38). CONCLUSIONS: Due to the observed moderate-to-strong proportional biases within body composition estimates, particularly for Hispanic females, the need for ethnic-specific algorithms is warranted.

Body Fluid Estimation Via Segmental Multi-Frequency Bioelectrical Impedance Analysis Following Acute Resistance Exercise

Segmental multi-frequency bioelectrical impedance analysis (S-MFBIA) estimates body composition and fluids by passing electrical currents through the body and can separate the body into distinct segments. The minimum required abstention from exercise before S-MFBIA is unclear. PURPOSE: The purpose of this study was to monitor changes in total body water (TBW), intracellular water (ICW), and extracellular water (ECW) estimated via S-MFBIA following acute, localized bouts of resistance exercise (RE). METHODS: Thirty-two female (n = 18; age: 22.7 ± 1.4 y; height: 167.5 ± 7.5 cm; body mass: 66.6 ± 14.5 kg; body fat: 30.3 ± 6.2%) and male (n = 14; age: 24.2 ± 2.9; height: 178.7 ± 5.3; body mass: 85.7 ± 7.8 kg; body fat: 19.6 ± 6.9%) resistance-trained volunteers completed three randomly assigned conditions in a crossover design. Each RE protocol (REUPPER or RELOWER) consisted of three exercises and began with two warm-up sets of 12-15 repetitions per exercise. This was followed by a RE circuit of 5 sets of 10 repetitions per exercise with a one-minute rest interval between circuits. In the resting (REST) condition, participants did not complete any physical activity. S-MFBIA was performed at five timepoints: pre-exercise, immediate post-exercise, 15-, 30-, and 60-minutes post-exercise. Data were analyzed using linear mixed-effects models with a random intercept for participant. In all models, REST was the reference condition, and pre-exercise was the reference time point. RESULTS: Although body mass did not differ between conditions, condition by time interactions were observed for TBW, ICW, and ECW (p < 0.001 each), with the higher values observed at post-exercise time points in REUPPER as compared to the REST condition. Mean differences between REUPPER and REST for TBW, ICW, and ECW ranged from 0.6-1.0 kg, 0.4-0.6 kg, and 0.2-0.4 kg, respectively. Conversely, RELOWER did not alter fluid estimates. CONCLUSIONS: An acute increase in TBW, ICW, and ECW is detected by S-MFBIA after a single bout of upper body, but not lower body, RE. This could be due to the smaller initial diameter and greater relative change in diameter of the arms as compared to legs. Due to the potential of artificial body fluid changes, users should avoid exercise - particularly upper body exercise - prior to S-MFBIA assessments.

Comparison Of A Novel Body Mass Index Equation To Body Composition Methods In Collegiate Athletes

INTRODUCTION: Accurate assessment of body composition in collegiate athletes is an effective tool to enhance training and nutrition protocols. The use of Body Mass Index (BMI) based equations for such purposes has been found to be relatively inaccurate in competitive athletes due to the inability to decipher between fat and fat-free mass. Recently, a BMI based equation developed by Nickerson et. al. (BMINICKERSON) that incorporates handgrip strength as a surrogate for lean mass was found to estimate body fat with low error in general population adults. The use of such a method in collegiate athletes may therefore be advantageous as a cost-effective and easily administered option for body composition assessment. PURPOSE: To compare the accuracy and effectiveness of BMINICKERSON with traditional body composition methods in estimating body fat percentage of Division II collegiate athletes. METHODS: Fifteen (n = 15) intercollegiate athletes (n = 9 male, 6 female) were assessed for percentage body fat using BMINICKERSON, bio-electrical impedance analysis (BIA) and seven site skinfold (SF). A One-Way repeated measures ANOVA was utilized to determine potential differences in body fat as estimated by each method. RESULTS: A significant difference in body fat percentage as assessed by the included methods was found for the sample (F = 16.78, p < 0.001). Further paired samples t-testing revealed a significantly greater body fat estimation by BMINICKERSON (20.84 % ± 6.73 %) in comparison to both BIA (t = 9.06, p < 0.001, 16.31 % ± 6.72 %) and skinfold (t = 4.57, p < 0.001, 16.34 % ± 8.34 %). Measurement of body fat percentage by BIA and skinfold did not significantly differ (t = 0.02, p = 0.98). CONCLUSION: Although use of BMINICKERSON in estimating body composition has been shown to provide relatively accurate results in the general population, the current study did not observe the same in collegiate athletes. The use of other cost-effective and easily administered methods, such as BIA and SF, may provide for more accurate estimation of body fat in the current population. Further research comparing BMINICKERSON to a gold standard measurement technique in collegiate athletes is warranted.

A Review of Commercially Available 3D Surface Imaging Systems for Body Composition Estimation

Recent literature has suggested 3D surface imaging to be a potential method of estimating body composition. The aim of this study was to provide an overview of commercially available 3D surface imaging systems that provide body composition estimates. User and system details of complete commercially available whole body 3D surface imaging systems, which estimate body composition, were collated from May to June 2022. Six 3D body surface imaging systems were identified, each of which provided varying amounts of user and system details. As this information is necessary to ensure the correct selection of system, appropriate use, and interpretation of outputs, manufacturers should seek to publicly present more detailed user and system details, international standards groups and training associations should seek to encourage standardisation, and practitioners and researchers should request additional details where necessary and validate their system prior to use, and end users should cautiously interpret outputs without the availability of comprehensive user and system details.

A new anthropometric model for body composition estimation: Comparison with a bioelectrical impedance consumer device.

The present study refers to an anthropometric model, Dahlmann-Body-Analysis (DBA), based on formerly developed weight-height-frame tables. Including the anthropometric variable abdomen circumference (AC), a further differentiation into muscularity and fat mass could be realized. This enables to calculate the individual percentage fat mass (%FM), providing a cost-effective method for epidemiological studies. The present work sets out to investigate, whether %FM computed by the DBA model compares to BIA measurements, notably under conditions of heavy obesity. In 103 adults (37 males, 66 females, age 42.5 ± 12.5 years, BMI 38.2 ± 4.8 kg/m²) %FM was estimated by a tetrapolar BIA device and compared to results derived by the DBA system. Bland-Altman and simple linear regression analyses were used to determine agreement between methods. The mean %FM estimates of men (women) ± standard deviation were 36.1 ± 4.8 (49.7 ± 4.5) for BIA and 36.7 ± 4.2 (49.1 ± 4.9) for DBA measurements. Pearson correlation coefficients (r) and Lin's concordance correlation coefficient (CCC) were r = 0.86 and CCC = 0.84 for men and r = 0.85 and CCC = 0.83 for women, respectively. Bland-Altman plot showed limits of agreement between DBA and BIA %FM that ranged from 5.5% to -4.3% for men and 4.6% to- 5.7% for women, respectively. Correlations between values measured by both methods were high and the observed confidence interval (SD of the difference between DBA and BIA result multiplied by 2) was low. No systematic error was found. The DBA system overestimates FM by 0.63 ± 4.98 (2SD) % for men and underestimates FM by -0.56 ± 5.28 (2SD) % for women, respectively, compared to the BIA results. The result for both genders is -0.066 ± 5.17 (2SD) %FM. Over all, there is a strong concordance and reproducibility between the DBA and BIA data sets. The implementation of the abdomen circumference (AC) into the DBA model as a proxy for body fat (%FM) resulted in a strong concordance with BIA measurements. These findings indicate that the DBA model may reflect the body shape of severely obese white European patients with regard to body composition.

Development and Validation of Waist Girth-Based Equations to Evaluate Body Composition in Colombian Adults: Rationale and STROBE-Nut-Based Protocol of the F20 Project.

Waist girth (WG) represents a quick, simple, and inexpensive tool that correlates with excess of fat mass in humans; however, this measurement does not provide information on body composition. The evaluation of body composition is one of the main components in the assessment of nutritional status. Indeed, the use of anthropometry-based equations to estimate body fat and fat-free mass is a frequent strategy. Considering the lack of validation in the Colombian population, the aim of this research study (the F20 Project) is to externally validate WG-based equations (e.g., relative fat mass), and also to develop and validate new models that include WG to estimate body composition in Colombian adults compared to DXA. This cross-sectional study will be carried out following the guidelines for Strengthening the Reporting of Observational Studies in Epidemiology–Nutritional Epidemiology (STROBE–nut). Using stratified probabilistic sampling, the study population will be adults with different levels of physical activity residing in Medellín and its metropolitan area. The results of this study will not only validate the estimation performance of the current WG-based equations, but they will also develop new equations to estimate body composition in the Colombian population. This will improve professional practice in health, exercise, and sports sciences (ClinicalTrials.gov ID #NCT05450588).

Genetic parameters for residual feed intake, methane emissions, and body composition in New Zealand maternal sheep.

There is simultaneous interest in improving the feed efficiency of ruminant livestock and reducing methane (CH4) emissions. The relationship (genetic and phenotypic) between feed efficiency (characterized as residual feed intake: RFI) and greenhouse gases [methane (CH4) and carbon dioxide (CO2)] traits in New Zealand (NZ) maternal sheep has not previously been investigated, nor has their relationship with detailed estimates of body composition. To investigate these relationships in NZ maternal sheep, a feed intake facility was established at AgResearch Invermay, Mosgiel, NZ in 2015, comprising automated feeders that record individual feeding events. Individual measures of feed intake, feeding behavior (length and duration of eating events), and gas emissions (estimated using portable accumulation chambers) were generated on 986 growing maternal ewe lambs sourced from three pedigree recorded flocks registered in the Sheep Improvement Limited database (www.sil.co.nz). Additional data were generated from a subset of 591 animals for body composition (estimated using ultrasound and computed tomography scanning). The heritability estimates for RFI, CH4, and CH4/(CH4+CO2) were 0.42 ± 0.09, 0.32 ± 0.08, and 0.29 ± 0.06, respectively. The heritability estimates for the body composition traits were high for carcass lean and fat traits; for example, the heritability for visceral fat (adjusted for body weight) was 0.93 ± 0.19. The relationship between RFI and CH4 emissions was complex, and although less feed eaten will lead to a lowered absolute amount of CH4 emitted, there was a negative phenotypic and genetic correlation between RFI and CH4/(CH4+CO2) of −0.13 ± 0.03 and −0.41 ± 0.15, respectively. There were also genetic correlations, that were different from zero, between both RFI and CH4 traits with body composition including a negative correlation between the proportion of visceral fat in the body and RFI (−0.52 ± 0.16) and a positive correlation between the proportion of lean in the body and CH4 (0.54 ± 0.12). Together the results provide the first accurate estimates of the genetic correlations between RFI, CH4 emissions, and the body composition (lean and fat) in sheep. These correlations will need to be accounted for in genetic improvement programs.

O3 An alternative approach to estimation of energy transactions and body composition in sheep

O3 An alternative approach to estimation of energy transactions and body composition in sheep

Body composition in term neonates of mothers with hypertensive disorders of pregnancy.

Neonates of gravidas with hypertensive disorders of pregnancy (HDP) are at increased lifelong risk of cardiometabolic complications. Neonatal adiposity measured by body composition (BC) is a better surrogate of nutritional status than birth weight. Data comparing BC in term neonates of hypertensive and normotensive pregnant patients is lacking. Our objective was to compare body composition in both groups of neonates. This was a retrospective cohort study from March 2018 to June 2019 at our tertiary institution where term neonatal BC are routinely measured. Neonates of patients with HDP and matched controls were included. Skin fold thickness (SFT) and percent body fat (PBF) were calculated using a validated anthropometric formula and compared using Mann-Whitney U and chi-square tests. One hundred and forty-two neonates of patients with HDP were compared to 150 controls. Demographic characteristics were similar except for higher pre-pregnancy BMI (29.7 ± 8.4 vs 26.75 ± 7.1, p = <0.01) in the HDP group. SFT was not significantly different (4.6 vs 4.4 mm, p = 0.09) but PBF was higher in the hypertensive group (13.15 vs 11.72, p = 0.01). PBF is higher in neonates of mothers with HDP, which may contribute to an increased risk of cardiometabolic complications later in life. Birth weight percentiles do not explain the predisposition to cardiovascular complications in offspring of hypertensive mothers. Body composition estimation may provide an explanation for this increased risk. Percent body fat is higher in term neonates of mothers with hypertensive disorders of pregnancy than neonates of normotensive mothers. Body composition is different in term neonates of mothers with hypertensive disorders of pregnancy.

Metagenomic analysis reveals associations between salivary microbiota and body composition in early childhood

Several studies have shown that body mass index is strongly associated with differences in gut microbiota, but the relationship between body weight and oral microbiota is less clear especially in young children. We aimed to evaluate if there is an association between child growth and the saliva microbiome. We hypothesized that associations between growth and the saliva microbiome would be moderate, similarly to the association between growth and the gut microbiome. For 236 toddlers participating in the New Hampshire Birth Cohort Study, we characterized the association between multiple longitudinal anthropometric measures of body height, body weight and body mass. Body Mass Index (BMI) z-scores were calculated, and dual-energy x-ray absorptiometry (DXA) was used to estimate body composition. Shotgun metagenomic sequencing of saliva samples was performed to taxonomically and functionally profile the oral microbiome. We found that within-sample diversity was inversely related to body mass measurements while community composition was not associated. Although the magnitude of associations were small, some taxa were consistently associated with growth and modified by sex. Certain taxa were associated with decreased weight or growth (including Actinomyces odontolyticus and Prevotella melaninogenica) or increased growth (such as Streptococcus mitis and Corynebacterium matruchotii) across anthropometric measures. Further exploration of the functional significance of this relationship will enhance our understanding of the intersection between weight gain, microbiota, and energy metabolism and the potential role of these relationships on the onset of obesity-associated diseases in later life.