Percentage fat (%FM) and fat-free mass (FFM) were measured in 37 children from a sports academy and in 71 children from standard schools with dual x-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA) using the manufacturer’s equation (Tanita) and an ethnic-specific prediction equation (Haroun). In the standard school, BIA overestimated FFM and underestimated %FM by a mean of 2.5 kg and 5.2%, respectively, using the Tanita equation. In girls from the sports academy, the Tanita equation underestimated FFM and overestimated %FM compared with DXA (mean difference BIA-DXA; FFM: −1.3 kg; %FM: 1.8%).
