PHYSICAL ACTIVITY, DIET AND ADIPOSITY IN BLACK AND WHITE TEEN-AGERS

Abstract

PURPOSE To determine the relations of physical activity (PA) and diet to percent body fat (%BF) in black (n = 141) and white (n = 140) youths, 14–18 y of age. METHODS %BF was measured with dual-energy x-ray absorptiometry. Free living moderate-vigorous PA (MVPA) and diet were assessed with 6.1 (±1.4) independent 24-h recalls over a 12-week period. RESULTS The girls (n = 173, 29.8%BF) were higher (p < .001) than the boys (n = 108, 17.3%BF) in adiposity; the race effect and the race × sex interaction were not significant. Multiple regression showed that lower %BF was associated with more MVPA (p = .002 partial r = −.18) and greater energy intake (p = .05, partial r = −.12). Similar results were obtained when fat intake was used in place of energy intake. None of the 2-way interactions among race, sex, MVPA and energy intake were significant. Sex-specific correlations between MVPA and %BF were r = −.27 (p = .005) for the boys and r = −.22 (p = .004) for the girls. The correlation of energy intake with %BF was r = −.03 (n.s.) for the boys and r = −.21 (p = .006) for the girls. CONCLUSION Lower degrees of adiposity were associated with a higher energy throughput, as indicated by higher amounts of PA and energy intake; the association of higher energy intake with lower %BF was clearer in girls than in boys. Supported by NIH (HL64157).