Validity of Hand-to-Foot and Foot-to-Foot Consumer-Grade Bioimpedance Analysis for Body Composition Estimation

Authors

Adhirath Malladi, Texas Tech UniversityFollow
Carina M. Velasquez, Texas Tech UniversityFollow
Christine M. Florez, Texas Tech UniversityFollow
Ainsley E. Way, Texas Tech UniversityFollow
Madison H. Sullivan, Texas Tech UniversityFollow
Julia Whitson, Texas Tech UniversityFollow
Reva Ann Rudolph, Texas Tech UniversityFollow
Grant M. Tinsley, Texas Tech UniversityFollow
John Alexander, Texas Tech UniversityFollow

Abstract

Consumer-grade bioimpedance analysis (BIA) devices are inexpensive and widely accessible, providing rapid, noninvasive body composition estimates that are frequently used in fitness and clinical settings to monitor changes over time. However, their validity for estimating body fat percentage relative to laboratory methods such as dual-energy X-ray absorptiometry (DXA) remains uncertain. PURPOSE: To evaluate the validity of hand-to-foot and foot-to-foot measurements for two widely used consumer-grade BIA devices when estimating body fat percentage compared with DXA and to determine whether the BIA–DXA difference changes across the range of body fat percentage (i.e., BF%-dependent error/proportional bias). METHODS: Eighty-three healthy adults, including 50 females (age: 31.7 ± 16.0 y; body mass index: 23.5 ± 4.2 kg/m²) and 33 males (age: 25.0 ± 5.0 y; body mass index: 25.7 ± 3.8 kg/m²) were evaluated at a single research visit using DXA (GE iDXA), hand-to-foot consumer BIA (GE C510G), and foot-to-foot consumer BIA (GE Fit Plus LN). Assessments were performed after an overnight (8-hour) period of fasting from food and fluid and ≥24 hours of abstention from exercise. Body fat percentage estimates from each consumer BIA device were compared to DXA using paired t-tests, Bland-Altman analysis, and calculation of R² and standard error of the estimate (SEE); proportional bias was assessed to test whether the BIA–DXA difference varied as %BF increased (non-constant underestimation). RESULTS: Body fat percentage was underestimated by hand-to-foot BIA (23.3 ± 7.4%; pCONCLUSION: Both hand-to-foot and foot-to-foot consumer BIA devices significantly underestimated body fat percentage compared with DXA and demonstrated poor agreement. These findings indicate that neither device is interchangeable with DXA for %BF estimation in adults, and BF%-dependent error (proportional bias) may mislead individual assessment or tracking, particularly for individuals with higher %BF.

Recommended Citation

Malladi, Adhirath; Velasquez, Carina M.; Florez, Christine M.; Way, Ainsley E.; Sullivan, Madison H.; Whitson, Julia; Rudolph, Reva Ann; Tinsley, Grant M.; and Alexander, John (2026) "Validity of Hand-to-Foot and Foot-to-Foot Consumer-Grade Bioimpedance Analysis for Body Composition Estimation," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 18, Article 86.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss18/86