Agreement in Body Fat Percentage Estimates Between Three Common Bioelectrical Impedance Analysis Devices and a Myography-Based Analyzer in Healthy Young Adults

Background: Body composition assessment is highly relevant in various fields, including health and performance. This study aimed to evaluate the agreement in body fat percentage (BF%) estimates between three bioelectrical impedance analysis (BIA) devices (InBody 770, Omron HBF-514C, and Tanita BC-533) and a myography-based analyzer (Skulpt Chisel® Skulpt Inc., San Francisco, CA, USA). Methods: BF% was assessed in 115 participants (33 women, 82 men) using four different devices in random order. Results: In contrast to the InBody, the results showed that the Omron overestimated (p = 0.001) BF% (by 2.5% in men and 4.0% in women), whereas the Tanita underestimated it (by 2.4% in men and 3.8% in women). In women, the Skulpt® also underestimated BF% (3.6%; p = 0.001), whereas in men, the estimate was like that of the InBody 770 (0.8%; p = 0.184). Conclusions: Although some devices demonstrated relatively small mean differences compared with the InBody 770, Bland–Altman analyses indicated considerable individual-level variability between devices. Thus, similarity in group-level BF% estimates should not be interpreted as individual-level agreement, and the devices should not be used interchangeably for longitudinal monitoring of BF% changes.