To determine whether participation in organized outdoor team
sports and structured indoor nonschool activity programs in
kindergarten and first grade predicted subsequent 4-year change
in body mass index (BMI; calculated as weight in kilograms
divided by height in meters squared) during the adiposity
rebound period of childhood. Longitudinal cohort study. Forty-
five schools in 13 communities across Southern California.
Largely Hispanic and non-Hispanic white children (N = 4550) with
a mean (SD) age at study entry of 6.60 (0.65) years. Parents
completed questionnaires assessing physical activity,
demographic characteristics, and other relevant covariates at
baseline. Data on built and social environmental variables were
linked to the neighborhood around children's homes using
geographical information systems. Main Outcome Measures Each
child's height and weight were measured annually during 4 years
of follow-up. After adjusting for several confounders, BMI
increased at a rate 0.05 unit/year slower for children