Male and female differences in variability with estimating body fat composition using skinfold calipers

Obesity is a major health problem in the United States. Skinfold measurements are routinely used in assessing outcomes in the management of obesity. The purpose of this study was to determine if sex differences in skinfold measurements would be apparent in intraobserver and interobserver reliability as well as validity when compared with bioelectrical impedance analysis (BIA) measurements.

To determine intraobserver and interobserver variability, 71 male and 45 female subjects (chiropractic students) were assessed by 4 separate observers who each took 4 separate skinfold measurements. Bioelectrical impedance analysis was later conducted using a foot-to-foot technique. The average sums of the skinfold measurement and their standard deviations were calculated, and correlation coefficients between skinfold measurements and BIA techniques for male and female subjects were plotted separately to assess validity.

Men tended to have greater amounts of intraobserver and interobserver variability when compared with women, but these differences were not significant. In regard to validity, there was no significant difference between skinfold measurements and BIA when estimating percentage body fat for men; but the difference was significant for women, where BIA underestimated by 3.4%.

The differences observed in variability could be explained by the fact that there is a difference in skinfold compressibility between men and women. Physicians who are using skinfold calipers for body composition assessment should take into account these small potential differences when evaluating total body fatness.