Submitted to: American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/10/2000
Publication Date: 8/20/2000
Citation: WONG,W.W., STUFF,J.E., BUTTE,N.F., SMITH,E.O., ELLIS,K.J., ESTIMATING BODY FAT IN AFRICAN AMERICAN AND WHITE ADOLESCENT GIRLS: A COMPARISON OF SKINFOLD-THICKNESS EQUATIONS WITH A 4-COMPARTMENT CRITERION MODEL, AMERICAN JOURNAL OF CLINICAL NUTRITION, 2000. v. 72(2). p. 348-354. Interpretive Summary: Obesity is an increasing problem among children in the United States. Scientists have developed a number of skinfold-thickness equations used to estimate body fat in studies. However, these were primarily developed using data on Caucasian adults. Also, the density of fat-free mass was assumed to be constant, and we know that density of fat-free mass changes with age and differs between black and white people. We therefore wanted to determine the accuracy of these equations by comparing them to black and white female adolescent subjects' exact measurements based on a four-compartment reference model. Based on our results, the quadratic equation of Slaughter, Lohman and Boileau is recommended for population studies in female adolescents of these races because of its accuracy and simplicity, although individual fat mass can be off by about 9 percent.
Technical Abstract: Background. Although skinfold thickness equations are widely used to estimate body fat, their accuracy in a biracial population of female adolescents has not been established. Objective: We undertook this study to determine the agreement between eight widely used skinfold thickness equations and a 4-compartment criterion model in predicting the percentage of body fat of 72 Caucasian and 40 African-American girls aged 13.0 +/- 1.9 y. Design: The biceps, triceps, suprailiac, subscapular, thigh, and abdominal skinfold thicknesses of subjects were measured with Lange skinfold calipers and the buttocks circumference with a metal tape. The percentage of fat mass (%FM) predicted using each skinfold thickness equation was compared to the criterion %FM calculated by the 4-compartment model based on measurement of body density, body water, and bone mineral content. Results: Bland and Altman analysis indicated that the quadratic equations agreed most closely with the 4-compartment model's measurement of %FM. Agreement of the other equations varied with body fatness. When the ethnic groups were analyzed separately, the quadratic equations remained the best equations for predicting %FM among the Caucasian and African- American girls. Conclusions: The quadratic equation of Slaughter, Lohman and Boileau is recommended for population studies in female adolescents because of its accuracy and simplicity. However, an individual %FM can be over- or underestimated by approximately 9% when this skinfold thickness equation is used.