A Large-Scale Evaluation into the Accuracy of Bioelectrical Impedance Devices for Assessing Body Composition: A 10-Year Analysis in Canadian University Students

<ns3:p>Background: The assessment of body composition can be conducted using a variety of devices, each providing practitioners unique advantages such as cost effectiveness, efficiency, accessibility, and accuracy. The purpose of this study was to evaluate the precision of three bioelectrical impedance analysis (BIA) devices when compared to air displacement plethysmography (BOD POD). Methods: A large-scale study involving 617 undergraduate kinesiology students (♀ = 342 | ♂ = 275) participated in this study. Participants had a mean ( SD) age of 21.2 2.0 y, a height of 171.9 9.9 cm, and a weight of 71.6 15.2 kg. Each participant completed a body composition assessment using the following BIA equipment: Tanita BC-568, Tanita BF-683W, and InBody 230 to estimate body fat (%). Air plethysmography (BOD POD) was used as the criterion method for deriving body composition. Order of assessments were randomized and were performed 1hr apart on the same day. Results: All data sets were positively skewed and determined to be non-normally distributed after conducting a Shapiro-wilk assessment (p < 0.05). Statistically significant differences in the mean absolute error between the criterion and each BIA device were observed: Tanita-568 (MAE = 4.8, p < 0.0001), Tanita-683 (MAE = 5.8, p < 0.0001) and InBody 230 (MAE = 4.6, p = 0.046). The calculated effect size between each BIA device and the criterion revealed trivial differences (ES 0.16). Conclusion: Overall, the InBody 230 BIA device displayed the strongest agreement with the BOD POD.</ns3:p>