Comparison of Multi-Frequency Bioelectrical Impedance and Dual-Energy X-Ray Absorptiometry to Assess Body Composition in College-Aged Adults.

The purpose of this study was to evaluate the validity of whole body percent fat (%BF) and segmental fat-free mass (FFM) using multi-frequency bioelectrical impedance analysis (MF-BIA) and dual-energy x-ray absorptiometry (DEXA) in college-aged adults. Sixty-two participants male (n = 32) and female (n = 30) completed MF-BIA and DEXA measurements following established pre-test guidelines. %BF and segmental FFM (right arm, left arm, trunk, right leg, and left leg) were collected and analyzed. The MF-BIA significantly (p < 0.05) underestimated %BF for all participants, females, and males compared to DEXA. In addition, MF-BIA significantly (p < 0.05) underestimated FFM in the arms and legs in all participants and males with the exception of the left arm in all subjects while significantly overestimating FFM in the trunk. In females, the MF-BIA overestimated FFM in the arms and trunk while significantly (p < 0.05) underestimating FFM in the legs. Difference plots also indicated that the underestimation of FFM from MF-BIA in the arms and legs increased as the amount of FFM increased. Thus, our findings suggested that the MF-BIA may not be accurate for measuring whole %BF and segmental FFM in the college-aged population.