Predictive accuracy of skinfold equations for estimating body density of African-American women

    loading  Checking for direct PDF access through Ovid



The purpose of this study was to compare the predictive accuracy of previously published skinfold (SKF) equations for estimating body density of 134 premenopausal African-American women (18 to 40 yr).


The equations cross-validated were: the sum of seven skinfolds equation (JPW7) and the sum of three skinfolds equation (JPW3), both of Jackson et al.(1980); the generalized equation (DWgen) and the age-specific equation (DWage) of Durnin and Womersley (1974); and the equation of Wang et al. (1994). Total body density was determined by hydrodensitometry (BDuww) at residual lung volume and converted to %BFuww using the Siri (1991) formula. The predictive accuracy of the SKF equations tested in this study was evaluated using the cross-validation procedures outlined by Lohman (1992).


The validity coefficients (ry,y′) ranged from 0.83 (DWgen) to 0.87 (JPW7). The SEEs ranged from 0.0076 g·cc−1 (DWage) to 0.0122 g·cc−1 (Wang), and the total errors ranged from 0.0103 g·cc−1 (JPW7) to 0.0478 g·cc−1 (Wang). The percentage of individual residual scores falling within ± 3.5%BF for this sample ranged from 31% (DWage) to 58% for the JPW7 equation. Comparison of the predictive accuracy of the five equations indicated that the JPW7 equation was the most valid equation, explaining 75% of the variance in reference body density with no significant difference between average reference BDuww (1.03035 g·cc−1) and average predicted BDJPW7 (1.03152 g·cc−1).


We recommend using the JPW7 equation to assess body composition and %BF of premenopausal African-American women.

Related Topics

    loading  Loading Related Articles