ETHNIC AND AGE TRENDS FOR BODY-COMPOSITION IN WOMEN RESIDING IN THE US SOUTHWEST .2. TOTAL FAT

This study assessed body density (ED) in an ethnically diverse sample of women (African American, Caucasian, Mexican American and Native Ame rican) (N = 139) who were between 20 and 30 or 40 and 50 yr of age and of normal weight for their height. ED was assessed using three method s: hydrostatically determined density (UWW), total body potassium (TBK ) and the Jackson ct al. (1980) sum of seven SF with gluteal circumfer ence (SF). Ethnic differences in ED were detected by TBK and UWW. ED f rom SF did not detect ethnic differences, and the SEE was unacceptable Based on multiple regression, the prediction equation was: ED = 1.119 7794 - 0.000224382 (X(3)) + 0.006999 (e2) - 0.000320177 (X(2)) - 0.001 892 (el) + 0.001750 (e3) - 0.000537005 (x(1)) (where x(1) = gluteal C, x(2) = age in years, x(3) = sum of 7 SF and e1, e2, and e3 describe e thnicity). This formula had a reduced SEE, a higher correlation with h ydrostatically determined BD, and was sensitive to ethnic differences detected with other measures of ED. A 24-mmol decrease in potassium wa s found when comparing the older Caucasian women with the younger Cauc asian women, while the difference for the African, Mexican, and Native American groups was 200-300 mmol.