University of Georgia researchers Irene Hatsu, Dawn McDougald and Alex Anderson investigated the effect of infant feeding mode on maternal body composition. They measured the weight and changes in body fat among 24 mothers who were 19-42 years old. Results showed that mothers who exclusively breastfed lost the most weight, most likely due to breastfeeding's high energy cost.

"Our results provide further evidence that exclusive breastfeeding promotes greater weight loss than mixed feeding among mothers, even in the early postpartum period," the scientists said. "This suggests there is the need to encourage mothers to exclusively breastfeed as a means of overweight and obesity prevention."

The research is reported in the International Breastfeeding Journal.