Comparison of Air-Displacement Plethysmography, Hydrodensitometry, and Dual X-ray Absorptiometry for Assessing Body Composition of Children 10 to 18 Years of Age

: Body density (Db) of 54 boys and girls 10–18 years of age (13.9 ± 2.4 years) was measured in an air‐displacement plethysmograph, the BOD POD®, and compared to Db determined by hydrodensitometry (HW). Both Db values were converted to percent body fat (%BF) using a two‐component model conversion formula and compared to %BF determined by dual energy X‐ray absorptiometry (DXA). Body density estimated from the BOD POD (1.04657 ± 0.01825 g/cc) was significantly higher than that estimated from HW (1.04032 ± 0.01872 g/cc). The relative body fat calculated from the BOD POD (23.12 ± 8.39 %BF) was highly correlated but, on average, 2.9% BF lower than %BF DXA. Average %BF estimates from HW and DXA were not significantly different. Despite consistently underestimating the %BF of children, the strong relationship between DXA and the BOD POD suggests that further investigation may improve the accuracy of the BOD POD for assessing body composition in children.