An evaluation of five indexes of relative body weight for use with children.

Five weight-to-height indexes frequently used in independence from height and age, with a sample of children. Four of the indexes failed to control for variations in the proportions of lean body mass and adipose tissue in children of different ages or heights. One index, the weight-for-length index, was found to be a reliable measure of relative body weight for use either in a clinical setting or in research. In order to test the validity of these findings, the same procedures were repeated with a second sample of children. In addition, the triceps skinfold thickness measurement was tested for reliability. Although the results for the first and second samples differed somewhat, the final conclusion of the study was that the weight-for-length index was the most reliable measure of relative body weight for children and youth.