DECREASED PHYSICAL-ACTIVITY IN PIMA INDIAN COMPARED WITH CAUCASIAN CHILDREN

Since reduced physical activity might be a risk factor for body weight gain, we studied the relationship between physical activity and body composition in 43 Pima Indian children (22 male/21 female, mean +/- s. d.: 9.9 +/- 1.1 years) and 42 Caucasian children (21 male/21 female, 9 .7 +/- 1.2 years). A list of usual sport leisure activities was establ ished (e.g. bicycling, swimming, basketball) and the subjects were ask ed how much time they had devoted to each activity over the past week and the last year. Data on time spent playing outside (excluding sport leisure activities for the estimation of physical activity) and watch ing television/videos were also collected. Pima Indians were taller (1 43 +/- 9 vs. 137 +/- 8 cm, P < 0.001), heavier (48.6 +/- 15.8 vs. 32.9 +/- 7.8 kg, P < 0.0001) and fatter (39 +/- 16 vs. 24 +/- 7% fat, P < 0.001) than Caucasians. Pima Indian girls showed significantly lower p ast year and past week sport leisure activity than Caucasian girls (P < 0.01) and spent significantly more time watching television/videos ( P < 0.05). Pima boys also showed significantly lower past week sport l eisure activity than Caucasian boys (P < 0.05). In Pima Indian boys, p ast year sport leisure activity correlated negatively (P < 0.05) with body mass index (r = -0.49) and percentage body fat (r = -0.56). Howev er, such correlations were not found in Pima Indian girls, possibly du e their very low levels of activity. Even though cause and effect cann ot be distinguished in cross-sectional studies, these findings suggest that decreased physical activity and increased television viewing may contribute to the development of obesity in Pima Indian children.