Comparison of existing skinfold equations for estimating body fat in African American and white women.

The purpose of this study was to compare seven skinfold equations with underwater weighing (UWW) for estimating body fat in 39 African American [age: 22.8 +/- 3.6 y (x +/- SD); weight: 59.6 +/- 8.3 kg) and 39 white (age: 22.1 +/- 2.9 y; weight: 61.7 +/- 7.3 kg) women. The hypothesis examined was that the equations would produce more accurate body fat estimates in white women, but would be appropriate for use in African American women. Body fat estimated from two quadratic, three linear, and two logarithmic skinfold equations was compared with body fat estimated from UWW; the same procedures were used to evaluate the results in both African Americans and whites. The data were analyzed by using t tests, analysis of variance, Scheffé's honestly significant difference tests, correlations, error assessments, and agreement. The results showed that total error, SEE, and SD values were larger in the African American women than in the white women and were not within acceptable limits listed in the literature. The correlation coefficients were lower in the African American women than in the white women. Agreement between the skinfold equations and UWW, based on deviations from mean differences, was better in the white women. In conclusion, the skinfold prediction equations evaluated in this study were more variable and produced more error when used in African American women. Therefore, population-specific equations for African American women should be used to estimate body fat because they will probably yield more accurate estimates.