Breastfeeding may attenuate BMI increase in children due to genetic risks

Researchers conducted a study to examine whether the duration and exclusivity of breastfeeding can attenuate BMI increase during childhood and adolescence due to genetic risks.

For people whose genes put them at risk of becoming obese, exclusive breastfeeding as a baby can help ward off weight gain later in life. Laurent Briollais of Mount Sinai Hospital and the University of Toronto and colleagues report these findings in a new study published June 11th in PLOS Genetics.

A growing body of research suggests that babies who consume only breastmilk are less likely to be overweight as children or adults, but the reasons behind this and other benefits of breastfeeding are not well understood. Briollais and colleagues investigated whether the weight-reducing impact of breastmilk can counteract the effects of genetic variations that increase the odds that a person will become obese. The researchers looked at genetic data and the body mass index (BMI) of more than 5,000 children from the ALSPAC study in the UK. In 18-year-old boys whose genes put them in the "high-risk" category for obesity, exclusive breastfeeding until 5 months of age reduced their BMI by 1.14 kg/m2. In girls, the impact was even larger, with a reduction of 1.53 kg/m2. Breastfeeding exclusively until 3 months of age, or a mix of breastmilk and formula, did not cause the same BMI reduction in high-risk individuals.