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

Abstract

Objectives: 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 R. The latter is widely recognized as one of the most accurate methods to measure human body composition. Methods: 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 R (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 (r s) and Pearson correlations (r) were used to evaluate the agreement between the two instruments. Results: The BOD POD R and InBody measurements were strongly correlated. Correlation was strongest for total body weight (r s (35) = .99, P < .0001), followed by fat mass (r (35) = .93, P < .0001). The lowest correlation was observed for fat-free mass (r s (35) = .79, P < .0001). Conclusions: The InBody 570 is reliable and compares favorably to the BOD POD R. 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).