Breastfeeding and obesity in Brazilian children.

Background: The association between breastfeeding and obesity is inconsistent by the literature. This study aims to assess whether obesity is associated to occurrence of breastfeeding and to duration of total and exclusive breastfeeding in Brazilian children.

Methods: A cross-sectional study was conducted with 764 children enrolled in public and private schools from Viçosa, Minas Gerais, Brazil. Obesity (outcome variable) was defined as body mass index above the +2 standard deviations score using sex and age specific standards of World Health Organization. Exposure was the occurrence and duration of breastfeeding. Potential confounders were controlled by multiple logistic regression analysis and were divided in two groups: children (gender, age, birth weight, gestational age, order of birth, number of siblings, number of persons in the residence, type of school, physical activity patterns and time watching television) and mothers (age, nutritional status, level of education, weight gain during pregnancy, smokes currently and during the pregnancy).

Results: Prevalence of obesity was 10.7%; 6.8% of the children were not breastfed and 59.0% did not receive exclusive breastfeeding. After adjustment for confounding variables by logistic regression analysis, no statistically significant association was observed between obesity and the occurrence and/or duration of total and exclusive breastfeeding. There was no dose-response effect of duration of breastfeeding on prevalence of obesity.

Conclusion: Our results do not support the hypothesis that breastfeeding promotion would reduce obesity in this population. Controversial findings regarding this association by literature indicate a need for further investigations.