Accuracy of Consumer Grade Bioelectrical Impedance Analysis Devices Compared to Air Displacement Plethysmography

The purpose of this study was to examine the accuracy of percent body fat estimates from seven different bioelectrical impedance analysis (BIA) models and a seven-site skin fold formula (SKF) compared with air displacement plethysmography (ADP) in females. Eighty-two female volunteers ranging from 19-67 years (31.96 ± 1.39) enrolled in this study. Body composition was assessed by seven site skin folds (SKF), ADP, Tetrapolar BIA (TBIA), and five consumer grade BIA devices: finger to finger (FF), hand to hand (HH) and three different leg to leg (LL1, LL2, LL3) models. In addition, LL3 was analyzed using the athletic (LL3a) and non-athletic modes (LL3b). The Institutional Review Board for Human Subjects at Eastern Washington University approved this study. The participants represented a wide range of percentage body fat (BF) as assessed by ADP (8.40 to 47.10, mean = 26.15 ± 0.93 SEE). No difference in the estimated percent body fat was found between ADP and SKF, TBIA, FF, HH, LL1, LL2, LL3a, and LL3b (r=0.862, 0.553, 0.775, 0.771, 0.765, 0.791, 0.798, 0.796 respectively; P\u3c0.001). Bland-Altman plots of the differences between % fat by ADP and BIA versus average % fat by the two methods showed no systematic differences for SKF and the seven BIA models (mean differences ± SD : SKF, 1.92 ± 4.25; TBIA, 0.73 ± 7.3; FF, -1.55 ± 5.34, HH, 1.37 ± 5.35; LL1, -4.70 ± 5.40, LL2, -3.72 ± 5.12 and LL3a, 1.70 ± 5.07; LL3b, -6.11 ± 31.40 p\u3c0.05). Skin fold measures were found to be the most reliable field method of estimating body composition. Of the BIA machines tested, the strongest relationship was found in the LL models with the LL3 in athletic mode (LL3a) being the most reliable. For the more affordable models, the LL2 was the most reliable compared to ADP

Validation of Three Body Composition Techniques with a Comparison of Ultrasound Abdominal Fat Depths against an Octopolar Bioelectrical Impedance Device

International Journal of Exercise Science 5(3) : 205-213, 2012. The aims of this study were to cross-validate three clinical-grade measures of body composition, using an octopolar Bioelectrical Impedance (BIA), an ultrasound analyzer (US) and Air-Displacement Plethysmography (ADP) and second to compare the US scans of total abdominal, subcutaneous and visceral fat depths (mm) against the trunk percent fat (%BF) from the octopolar BIA. Twenty-six college-aged (22.9 ± 1.35 years) men (n = 18) and women (n = 8) volunteered to participate in this study. Body composition was assessed using BIA (total and by segments), ADP and US. In addition, total abdominal, subcutaneous and visceral fat layers were measured using the US. All measurements were done in accordance with manufacturers’ guidelines. The %BF comparing the three clinical grade machines were all significantly correlated and no significant differences were found using a 1-way ANOVA. All three fat depths were significantly correlated to the trunk fat % via BIA, while significant differences were found for the 1-way ANOVA. A Tukey post-hoc test showed significant differences between the BIA trunk %BF and both subcutaneous and visceral US fat depths. Having valid ways to measure body composition and visceral fat that is accessible in terms of being transportable, cost effective, and simple to use, should become a part of preventive medicine