Breast-feeding history and overweight in 11 to 13-year-old children in Iran.

BACKGROUND The relationship between breast-feeding history and risk of overweight in pre-adolescent children was investigated. METHODS Children's breast-feeding history and demographics were obtained in interviewer-administered questionnaires of a multistage cluster sample survey of 800 parents of children aged 11-13 years living in Yazd, Iran. Height and weight were measured in the children. Overweight was defined as body mass index >/=90th age- and sex-specific percentile of the 2000 Centers for Disease Control reference values. RESULTS One hundred and four (13.0%) of 800 children were overweight. A total of 783 (97.9%) of the children had been breast fed. There was a markedly lower overweight prevalence among breast-fed than non breast-fed children. Controlling for age and sex, children breast fed for at least 24 months were substantially less likely to be overweight than children breast fed for less than 12 months (OR 0.56, 95% CI 0.31-0.9). A longer overall duration and duration of exclusive breast-feeding were associated significantly with the decreasing prevalence of overweight. CONCLUSION This sample of Iranian children shows high rates of overweight at young ages but also high rates of breast-feeding. The duration of breast-feeding is inversely related with the prevalence of overweight in pre-adolescent children.