Early Child Care and Adiposity at Ages 1 and 3 Years

BACKGROUND: The majority of infants in the United States are in nonparental child care, yet little is known about the effect of child care on development of obesity. OBJECTIVE: To examine the relationship between child care attendance from birth to 6 months and adiposity at 1 and 3 years of age. METHODS: We studied 1138 children from a prospective cohort of pregnant women and their offspring. The main exposure was time in child care from birth to 6 months of age, overall and by type of care: (1) child care center; (2) someone else's home; and (3) child's own home by nonparent. The main outcomes were weight-for-length (WFL) z score at 1 year and BMI z score at 3 years of age. RESULTS: A total of 649 (57%) infants attended child care; 17% were cared for in a center, 27% in someone else's home, and 21% in their own home by a nonparent. After adjustment for confounders, overall time in child care was associated with an increased WFL z score at 1 year and BMI z score at 3 years of age but not skinfold thicknesses. Center and own home care were not associated with the outcomes, but care in someone else's home was associated with an increase in both the 1- and 3-year outcomes. CONCLUSION: Child care in the first 6 months of life, especially in someone else's home, was associated with an increased WFL z score at 1 year and BMI z score at 3 years of age. Pediatrics 2009; 124: 555-562