Tyson Smoot, Andrea Arikawa
Dr. Andrea Arikawa | Brooks College of Health | Department of Nutrition and Dietetics
This study aimed at validating direct segmental multi-frequency bioelectrical impedance (BIA) as an effective means of measuring body composition when compared to air displacement plethysmography (ADP-Bod Pod) in adults. We also investigated the effect of recent water intake on the assessment of body composition by these methods. The study sample consisted of 61 healthy individuals, 24 males with mean age 25.5 and 38 females with mean age 22.2. Mean body mass index was 25.5 kg/m2 for males and 22.2 kg/m2 for females. Body composition was measured using three different assessment devices: Bod Pod, InBody 570, and Seca 514. Average body fat percentages were 28.1% (females) and 19.2% (males) when assessed by the Bod Pod, 27.6% (females) and 15.5% (males) by the InBody, and 27.1% (females) and 19.4% (males) by Seca. The Pearson’s correlation coefficient was r=0.923 (p<0.001), between the Bod Pod and Inbody, r=0.928 (p<0.001), between the Bod Pod and Seca, and r=0.96 (p<0.001) between Inbody and Seca. After drinking 1,000 mL water, the difference in % body fat assessed by InBody and Seca, respectively, was +1.43% and 1.46% for females and 0.86% and 1.49% for males. When it comes to changes in % body fat assessed by the Bod Pod, there was an increase by +0.67% in females, after drinking 1,000 mL water and +1.17% in males, after drinking 2,000 mL water. Our findings indicate that multi-frequency BIA is highly correlated with ADP, although ADP is less susceptible to recent changes in water intake.