Body fat gain and loss differentially influence validity of dual-energy x-ray absorptiometry and multifrequency bioelectrical impedance analysis during simultaneous fat-free mass accretion

摘要: The validity of dual-energy x-ray absorptiometry (DXA) and multifrequency bioelectrical impedance analysis (MFBIA) for detecting changes in fat mass (FM), fat-free (FFM), body percentage (BF%) was evaluated, as compared to a rapid 4-component (4C) model, 31 females completing 8 weeks resistance training. Analyses were performed all participants (ALL) subgroups that gained FFM but lost FM (R subgroup) or both (G subgroup). It hypothesized methods would comparably detect ALL, discrepancies occur subgroup analysis. Changes composition did not significantly differ between 4C, DXA, MFBIA. Equivalence testing indicated similar detected by DXA MFBIA, ΔFFM analyses ΔBF% ALL R subgroup. ΔFM equivalent 4C only G For ΔBF%, MFBIA produced magnitude errors ALL. However, exhibited lower error subgroup, whereas ΔFFM, relatively although displayed proportional bias weaker correlations with than DXA. In higher correlation Although may have utility estimating during accretion, be superior simultaneous loss, produce gain.