Agreement (DXA – 4 skinfold prediction equations) for percent body fat, fat mass, and fat-free mass in the healthy reference sample and in children with Down syndrome. Box represents mean difference between measures and error bars show the limits of agreement (1.96*SD). %BF, % body fat; FFM, fat-free mass; FM, fat mass; SF4, published equations (Brook, 1971, Durnin and Rahaman, 1967, Durnin and Womersley, 1974); New SF4, proposed equations.