ABSTRACT Background South African children face a double burden of malnutrition from undernutrition and rising obesity. Simple, accurate methods to estimate fat‐free mass, a key health indicator, are needed, as bioelectrical impedance analysis is limited by cost, availability and lack of local validation. Objectives To develop and validate prediction equations for fat‐free mass using simple anthropometric measurements in children aged 6–9 years. Methods In this cross‐sectional study, anthropometric and bioelectrical impedance data were obtained from 117 children. Bioelectrical impedance‐derived fat‐free mass was used as reference in multivariable regression models. Four equations were externally validated in 75 Black prepubertal children, using dual‐energy X‐ray absorptiometry‐derived fat‐free mass as standard. Relationships, mean differences, and agreement were assessed using Pearson's correlation, independent t ‐tests and Bland–Altman plots, respectively. Results Fourteen prediction equations, containing five to nine variables, were developed ( R 2 range: 0.88–0.92) in the sample of children (51% Black; 55% boys; 7.9 ± 0.8 years). Four equations were strongly correlated with dual‐energy X‐ray absorptiometry‐derived fat‐free mass ( r > 0.95; p < 0.001) in the validation sample (8.5 ± 1.3 years), and three yielded estimates with acceptable agreement (mean difference: 0.16–0.94 kg; limit of agreement: ±5 kg). Conclusion Fat‐free mass of prepubertal children can be predicted using simple anthropometric measurements, allowing assessment of body composition in low‐resource settings.
White et al. (Thu,) studied this question.