Breast-feeding duration for the prevention of excess body weight of mother-child pairs concurrently: a 2-year cohort study.

Objective: To examine the association between breast-feeding duration and the risk of excess body weight (children >85th percentile, mothers BMI≥25·0 kg/m2) concurrently in mother-child pairs two years after delivery.

Design: Prospective cohort study in Joinville, Brazil. Multivariable logistic regression was used to examine the independent relationship between breast-feeding duration and risk of excess body weight.

Setting: Brazilian public maternity hospital.

Subjects: Three hundred and five mother-child pairs.

Results: At 2-year follow-up, 23·6 % of mother-child pairs had excess body weight. Children breast-fed for <2 months were more likely to have excess body weight than children breast-fed for ≥6 months (OR=2·4; 95 % CI 1·1, 5·1). Breast-feeding for <2 months was also associated with a greater likelihood of maternal excess body weight compared with those who breast-fed for ≥6 months (OR=2·9; 95 % CI 1·1, 8·1). There was a progressive increase in the likelihood of mother-child pairs having excess body weight as breast-feeding duration decreased. In addition to breast-feeding duration, other independent determinants of excess body weight were pre-pregnancy weight, gestational weight gain and number of pregnancies in mothers, and birth weight in children.

Conclusions: Breast-feeding for a longer duration has a parallel protective effect on the risk of excess body weight in mother-child pairs two years after birth. Since members of the same family could be influenced by the same risk factors, continued promotion and support of breast-feeding may help to attenuate the rising prevalence of overweight in mother-child pairs.