Development of prediction equations for body composition in Indian children using bioelectrical impedance analysis

Abstract

We aimed to develop a BIA equation to predict fat free mass (FFM) using deuterium oxide (²H₂O) dilution as the reference method for children. Seventy seven children (36 boys and 41 girls), aged 6 to 24 month participated in the study. The best fit FFM prediction equation included weight, sex and length²/resistance (adjusted R²=0.83 and root mean square error of 0.49 kg). Applying ‘leave-one-out’ method the mean of the differences of FFM in kg and % body weight were nearly zero with 95% confidence intervals of ±0.108 kg between those derived by ²H₂O dilution and by the validated equation. PRESS statistic residual was 473g (»0). The best fit equation for FFMkg was:

FFMkg=0.72+0.30× (weight) +0.16× (sex) +0.52× (Length²/resistance)

(Length in cm, weight in kg, resistance in W, sex: boys=1, girls=0)

The derived predictive equation has good precision and is useful for community based studies on body composition in South Asian children.