Lack of consistency in the indirect methods of estimating percent body fat

Several studies have emphasized the relationship between body composition and the initiation and/or maintenance of cyclic ovarian function in women. A number of methods of indirectly calculating percent body fat have been used, but there is no clear evidence that the various calculations produce consistent results. We therefore compared five different ways of estimating the "percent body fat" in a total of 18 young women, including 6 normal control subjects who did not exercise, 6 regularly menstruating runners, and 6 amenorrheic runners. There was considerable individual variation in the estimates of body fat; and significant differences among groups were found by some, but not all, methods of calculation. It is suggested that because of the inconsistency of estimates, the use of the term "percent body fat" is misleading and that opposite conclusions may result from the use of different methods of calculating body fat in the same groups of individuals.