Objective: To test the hypothesis that the relationship between breastfeeding and later obesity would differ by race/ethnicity.
Design: Data were obtained from the Fragile Families and Child Wellbeing Study, a prospective birth cohort study.
Setting: Twenty large US cities in 15 states.
Participants: The 2146 three-year-old children in the study were born between 1998 and 2000 and were either non-Hispanic White, non-Hispanic Black, or Hispanic (any
Main outcome measures: Obesity was defined as having a BMI > or =95th percentile.
Results: Fifty-two percent of the children were ever breastfed and 18% were obese at 3 years of age. After adjustment for covariates (maternal BMI, smoking, age, relationship status, and education, plus the child's birth weight and the household income-to-poverty ratio), the relationship between breastfeeding and the prevalence of obesity was significantly different between White, Black, and Hispanic children (P = .02). The adjusted prevalence of obesity was lower in Hispanic children who were ever breastfed compared to those who were never breastfed (23.3% vs. 33.0%, P=.01), but there was no significant association between breastfeeding and obesity in either White or Black children (16.6% vs. 11.3%, P = .18 for Whites and 18.0% vs. 14.5%, P = .13 for Blacks).
Conclusions: In this study we found that the relationship between breastfeeding and obesity differed by race/ethnicity. Future studies examining the relationship between breastfeeding and later adiposity should consider the possibility that this relationship may differ by race/ethnicity.