This study reports the validity of body fat percentage (BF%) estimates from several commonly employed techniques as compared to a 5-component (5C) model criterion. Healthy adults (n=170) were assessed by dual-energy X-ray absorptiometry (DXA), air displacement plethysmography (ADP), multiple bioimpedance techniques, and optical scanning. Output was also used to produce a criterion 5C model, multiple variants of 3- A nd 4-component models (3C; 4C), and anthropometry-based BF% estimates. Linear regression, Bland-Altman analysis, and equivalence testing were performed alongside evaluation of the constant error (CE), total error (TE), standard error of the estimate (SEE), and coefficient of determination (R2). The major findings were: 1) Differences between 5C, 4C, and 3C models utilizing the same body volume (BV) and total body water (TBW) estimates are negligible (CE≤0.2%; SEE<0.5%; TE≤0.5%; R2=1.00; 95% limits of agreement [LOA]≤0.9%); 2) Moderate errors from alternate TBW or BV estimates in multi-component models were observed (CE≤1.3%; SEE≤2.1%; TE≤2.2%; R2≥0.95; 95% LOA≤4.2%); 3) Small differences between alternate DXA (i.e., tissue vs. region) and ADP (i.e., Siri vs. Brozek equations) estimates were observed, and both techniques generally performed well (CE<3.0%; SEE≤2.3%; TE≤3.6%; R2≥0.88; 95% LOA≤4.8%); 4) Bioimpedance technologies performed well but exhibited larger individual-level errors (CE<1.0%; SEE≤3.1%; TE≤3.3%; R2≥0.94; 95% LOA≤6.2%); and 5) Anthropometric equations generally performed poorly (CE:0.6 to 5.7%; SEE≤5.1%; TE≤7.4%; R2≥0.67; 95% LOA≤10.6%). Collectively, the data presented in this manuscript can aid researchers and clinicians in selecting an appropriate body composition assessment method and understanding the associated errors when compared to a reference multi-component model.
- air displacement plethysmography
- bioelectrical impedance analysis
- body fat
- dual-energy X-ray absorptiometry
- fat-free mass
- lean mass
- multi-compartment model