Multiple measures derived from 3D photonic body scans improve predictions of fat and muscle mass in young Swiss men

Abstract

Introduction Digital tools like 3D laser-based photonic scanners, which can assess external anthropometric measurements for population based studies, and predict body composition, are gaining in importance. Here we focus on a) systematic deviation between manually determined and scanned standard measurements, b) differences regarding the strength of association between these standard measurements and body composition, and c) improving these predictions of body composition by considering additional scan measurements. Methods We analysed 104 men aged 19-23. Bioelectrical Impedance Analysis was used to estimate whole body fat mass, visceral fat mass and skeletal muscle mass (SMM). For the 3D body scans, an Anthroscan VITUSbodyscan was used to automatically obtain 90 body shape measurements. Manual anthropometric measurements (height, weight, waist circumference) were also taken. Results Scanned and manually measured height, waist circumference, waist-to-height-ratio, and BMI were strongly correlated (Spearman Rho>0.96), however we also found systematic differences. When these variables were used to predict body fat or muscle mass, explained variation and prediction standard errors were similar between scanned and manual measurements. The univariable predictions performed well for both visceral fat (r 2 up to 0.92) and absolute fat mass (AFM, r 2 up to 0.87) but not for SMM (r 2 up to 0.54). Of the 90 body scanner measures used in the multivariable prediction models, belly circumference and middle hip circumference were the most important predictors of body fat content. Stepwise forward model selection using the AIC criterion showed that the best predictive power (r 2 up to 0.99) was achieved with models including 49 scanner measurements.

Digital Anthropometry: A Systematic Review on Precision, Reliability and Accuracy of Most Popular Existing Technologies

“…The 4693 participants in the 28 studies have an average age of 27.8 ± 12.6 years (range 2–83). Some studies evaluated only male subjects [ 24 , 25 , 26 , 27 ], while others evaluated only female subjects [ 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ], but both sexes are considered equally: 52% of participants were females, while 48% were males. Regarding the country of origin, nineteen studies were published in the USA [ 26 , 29 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ], three in Switzerland [ 24 , 25 , 27 ], one in the United Kingdom [ 48 ], two in Slovenia [ 49 , 50 ], one in Malaysia [ 28 ], one in Italy [ 30 ] and one in China [ 51 ].…”

Associations between relative body fat and areal body surface roughness characteristics in 3D photonic body scans—a proof of feasibility

“…The best association (quantified by R 2 ) with %BF was observed for Sa ( R 2 = 0.74), the arithmetic mean of roughness, which compared to other association studies of individual scanner-based measurements (e.g., circumferences, lengths, volumes) with aspects of body composition, and using comparable samples [ 17 ], represents a medium to strong association. However, somewhat stronger associations have been demonstrated when several scanner measurements were combined using different statistical methods [ 21 ].…”

“…Height and weight were measured with a standard stadiometer (Seca 274, Seca AG, Reinach, Switzerland). Further details of the measuring protocol are given in prior studies [ 6 , 17 , 21 ]. Raw scan datasets—in a proprietary point cloud format—were later triangulated and closed using the standard scanner software (Anthroscan, Version 3.5.3, Human Solutions, Kaiserslautern, Germany) and exported to the .obj file format.…”

“…Therefore, further linear regression models, including the mode (M7–M9), were computed. Linear regressions have proved suitable for initial evaluations of associations between 3D photonic body scan measurements and body composition (with relatively small added value for nonlinear methods) [ 6 , 17 , 21 ].…”

Increased Fat Mass Leads To Bone Loss, A Prospective Short-Term, 18-Week Study In Young Healthy Men Undergoing Basic Training of The Swiss Army

“…The rst measurement took place in March 2017 in Kloten (Canton Zurich, Switzerland); the follow-up measurement occurred 18 weeks later in July 2017 in Neunkirch (Canton Schaffhausen, Switzerland). The precise study protocol has been described previously (30,31). The subjects were Swiss male recruits from the air defence of the Swiss Armed Forces aged 19-23 years, starting their basic military training for 18 weeks.…”