Measurements of body density, defined as body mass (scale weight) divided by volume. Body volume can be obtained in a number of ways (see hydrostatic weighing). Densitometry is used to estimate the percentage body fat, since fatty tissue is less dense than lean tissue. One equation used is that of Siri: % body fat = (495/body density) − 450 (see also Brozec formula). The equation assumes that the densities of fatty tissue and lean tissue are relatively constant in all people. Unfortunately, the densities of lean tissues varies considerably between people.
Subjects: Sports and Exercise Medicine.