Evaluating The Validity Of Foot-foot And Hand-hand Bia Devices For Body Composition Assessment In Young Adults

PURPOSE: The purpose of this study was twofold. First, to compare percentage body fat results across the Hand-Hand BIA (HH) Foot-Foot BIA1 (FF1), and Foot-Foot BIA2 (FF2) devices. Second, identify which device provides values closest to the air displacement plethysmography (ADP) technique. METHODS: Five hundred and thirty-seven participants (317 females, age 21.2 ± 5.8 years, and 220 males age 22.6 ± 7.5 years) underwent percent body fat (%BF) assessments using four methods (ADP, HH, FF1, and FF2) in a randomized sequence to reduce bias. Pearson correlation assessed interrelationships, paired sample t-tests evaluated mean differences, and mean absolute differences (MAD) quantified individual errors. All analyses were sex specific. RESULTS: Mean ADP %BF values were 25.8 ± 7.6% for females and 14.5 ± 7.2% for males. Bias values for HH, FF1, and FF2 were -3.4%, -2.6%, and -1.4% for females, and -1.5%, -2.5%, and 1.4% for males, with all mean %BF significantly different from ADP (all p ≤ 0.001). Correlations ranged from 0.77 to 0.80 for females and 0.65 to 0.74 for males. MAD values for females changed from 4.1% to 5.0%, and for males from 4.1% to 4.6%. Significant mean differences were observed between HH and both FF devices (p ≤ 0.01). Correlations between HH and FF1, and HH and FF2, were 0.84 and 0.82 for females, and 0.74 and 0.72 for males. CONCLUSIONS: Moderate to moderately high correlations and significant mean differences were observed between ADP and BIA %BF measures. However, biases and MAD remained within the accepted margin of error for the instruments. Significant differences were also found between BIA devices, but biases and MAD were still within the acceptable range. Practical Applications: Both Foot-Foot and Hand-Hand BIA devices are valid for estimating %BF in young adults. However, it is not advisable to interchange the BIA devices when conducting pre- and post-assessment analyses.