Breastfeeding has long been seen as playing a vital role in improving child development. We now have evidence for some key breastmilk benefits, like helping keep infants in a healthy weight range.

A study in Obesity which followed 542 children until they were 5 years old found that those who were breastfed for 6 months or longer following birth had lower mean body mass index scores at ages 3–60 months, compared with those who were breastfed for shorter periods.

These findings provide further support for infant feeding guidelines that promote at least 6 months of breastfeeding. But breastfeeding moms should be encouraged to go easy on sweet drinks and added sugars during this crucial time. Using the Bayley-III Scales of Infant Development, researchers from the Children’s Hospital Los Angeles discovered that when mothers consumed large amounts of sugar-sweetened drinks and fruit juice during the first month of breastfeeding, the children showed poorer cognitive development scores at age 2.

When lactating women consume high amounts of simple sugars, such as fructose, these sugars could pass to infants through breast milk, potentially hampering the children’s brain development.

See also: The Not-So-Sweet News About Baby Food