American Journal of Clinical Nutrition, Vol 27, 1380-1385, Copyright © 1974 by The American Society for Clinical Nutrition, Inc.

A comparison of methods for estimating human body composition

¹ From the Department of Nutrition, Bioenergetics Division, Letterman Army Institute of Research, Presidio of San Francisco, California 94129

A comparison of three independent techniques to estimate body fat and water in a total population of 223 male soldiers and 36 WAC's (Womens Army Corp) was accomplished using three techniques involving independent body compartment parameters. Body density and fat were estimated from body volume by water displacement, whole-body burdens of potassium (⁴⁰K) were measured by a sodium iodide crystal shadow shield counter, and total-body water was obtained by analysis from the dilution of orally ingested deuterium oxide (D₂O) in body fluids. The estimate of the body fat compartment ( 17.2 kg) by each of the three methods did not differ significantly in the group of 89 males. The ⁴⁰K estimates of body fat (24.4 kg) of the group of 134 males was significantly higher than the body density (17.8 kg) or D₂O (16.0 kg) estimates. The combined population of 223 subjects showed all estimates of body fat, body density (17.8 kg), ⁴⁰K (21.6 kg), D₂O (15.6 kg) to differ significantly (P < 0.05) from each other. Densitometric estimates of body fat were similar for the two groups of males as well as the WAC's. The correlation between group estimates of body fat ranged between 0.47 to 0.72. Although significant differences in absolute magnitudes of the estimates were found, the three techniques are highly correlated (i.e., relative magnitudes were similar across techniques). The choice of technique as concluded from this study is then dependent on cost and mobility described since either of the three methods provide similar estimates.