Background: Body mass index (BMI) is formulated on the assumption that body weight (BW) scales to height with a power of 2 (BWfheight2), independent of sex and race-ethnicity. Powers differing from 2 are observed in studies of selected samples, thus raising the question if BMI is a generalizable metric that makes BW independent of height across populations. Objectives: The objectives were to test the hypothesis that adult BW scales to height with a power of 2 independent of sex and raceethnicity and to advance an understanding of BMI as a measure of shape by extending allometric analyses to waist circumference (WC).
