A Comparison of Body Composition Measurements Between Bioelectrical Impedance Analysis (inbody 570) and Air Displacement Plethysmography (BOD POD®)

The accurate measurement of body composition is important in both research and clinical practice. The aim of this study was to compare the InBody relative to the BOD POD®. The latter is widely recognized as one of the most accurate methods to measure human body composition. In the context of a clinical trial of 35 free-living non-athletic individuals [80% F, ages 40–69 years, BMI 25–34 kg/m2], we compared body composition measurements utilizing Bioelectrical Impedance Analysis (BIA) and Air Displacement Plethysmography (ADP). ADP was conducted in a BOD POD® (Cosmed USA Inc., Concord, CA, USA) and BIA measured using InBody 570 (In Body, Cerritos, CA, USA). Body measurements included total body weight, fat mass and fat-free mass which were obtained in kilograms following manufacturer instructions. Spearman's rank (rs) and Pearson correlations (r) were used to evaluate the agreement between the two instruments. The BOD POD® and InBody measurements were strongly correlated. Correlation was strongest for total body weight (rs (35) = .99, P < .0001), followed by fat mass (r (35) = .93, P < .0001). The lowest correlation was observed for fat-free mass (rs (35) = .79, P < .0001). The InBody 570 is reliable and compares favorably to the BOD POD®. Hence, it can be used in clinical settings and epidemiological studies as a practical and relatively inexpensive alternative to the BodPod and dual-energy x-ray absorptiometry (DEXA). Nutrition Research Center, School of Public Health, Loma Linda University, Loma Linda, CA, USA.