Updated

Obese women who breastfeed their children for at least four months are less likely to retain their pregnancy weight, according to a new study from U.S. health officials.

The researchers write in the journal Pediatrics that the benefit might be due to lactation causing the body to burn extra energy.

“This study suggests that improving adherence to breastfeeding recommendations may help reduce long-term maternal weight retention among obese mothers,” write the researchers, led by Andrea Sharma from the Centers for Disease Control and Prevention (CDC) in Atlanta.

Several studies have demonstrated benefits for children from breastfeeding, such as reduced obesity risk later in childhood. A study published in the same issue of the journal also found that breastfed children are more likely to eat fruits and vegetables and less likely to consume sugary drinks like soda.

Other papers published in this issue of the journal also found that eating habits in infancy may establish long term patterns for children's health.

One study found that children who drink sugary drinks during their first year of life are more likely to drink those types of beverages at age six. Another tied eating too few vegetables and fruits during infancy to eating less of those at six years old.

Still another study found that mothers who encourage their children to empty their bottles during infancy are more likely to pressure those children to eat more later on.

Less is known, though, about whether or how breastfeeding may influence the weight of new mothers years after their child is born.

For the new study, the team used data from previous research on breastfeeding conducted between 2005 and 2007. They included and compared data on the weight of 726 women from their third trimester of pregnancy to six years after they gave birth.

At the time, the recommendation from the American Academy of Pediatrics (AAP) was for new mothers to breastfeed for the first year of the child’s life, with the child's sole source of nutrition in the first four months of life being breastfeeding alone.

The AAP has updated their recommendation since the data was collected, and now advises one year of breastfeeding with the first six months being exclusively breastfeeding.

Overall, 29 percent of the women in the study exclusively breastfed for the first four months of the child’s life and about 20 percent exclusively breastfed for four months and then continued to breastfeed for at least a year.

For women who were considered normal weight or overweight, breastfeeding according to the guidelines at the time did not appear to be linked to how much weight they retained after delivery.

Obese women, however, retained about 18 fewer pounds after their pregnancy if they followed the guidelines compared to those who never breastfed.

Women are encouraged to gain some weight during pregnancy, but about half gain more weight than they should, the researchers write.

Doctors can be better educated to help obese women achieve their breastfeeding goals, the study team points out, adding that the likelihood of breastfeeding is also tied to other factors like hospital lactation support. There could be a focus put on those types of programs to increase breastfeeding rates among obese women, they say.