de Castro JAC, et al. – The physicians conducted this study to determine the validity of body composition analysis by bioelectrical impedance analysis (BIA)compared to dual–energy X–ray absorptiometry (DXA) and air displacement plethysmography (ADP) in children and adolescents an HIV diagnosis. For evaluating fat–free mass (FFM) and lean soft tissue mass (LSTM), BIA was suitable in children and adolescents with an HIV diagnosis. BIA was not suitable for performing an evaluation in both sexes for fat mass (FM), body fat percentage (%BF), and bone mineral content (BMC).