Breastfeeding Affects Body Fat After Birth

A recent study examined the relationship between the amount of trans fats in the diet and the breast milk of mothers of newborn babies and the body fat percentage in the babies. It was found that the percentage of body fat was less in mothers who breastfed their infants, despite consuming a high energy diet, while their infants tended to have slightly more body fat.

Breastfeeding an infant during the first six months is strongly recommended, considering its associated health benefits, both for the baby and the mother. Weight gain during pregnancy and obesity in mothers after childbirth are matters of concern, and so is the rising percentage of overweight infants. Most of the energy from breast milk is provided by fatty acids, the type and percentage of which are influenced by the fatty acids in the mother’s diet. Infant feeding formulas have less fatty acids than breast milk. This study was aimed at understanding links between the mother’s diet, infant feeding practice and the amount of fat in bodies of mothers and their infants.


  • A total of 96 adult women – African-American, Hispanic and Caucasian – who had delivered a normal weight, full-term baby less than three months before the beginning of the study were selected along with their babies for this study.
  • Based on the feeding pattern of the infants, they were divided into three groups: breastfed, mixed fed (breastfed and formula fed) and formula fed.
  • Mothers were interviewed about their medical and pregnancy history, daily dietary intake, physical activity, alcohol consumption and weight before pregnancy and weight gain after it. Information about birth weight and length of the baby, method of feeding and supplementary feeding was also obtained.
  • Weight, height/length and body composition of both mothers and infants were recorded and the data was analyzed.

Key findings

  • Mothers who breastfed their babies had a significantly higher carbohydrate intake than those who formula-fed their infants. They had a higher calcium intake compared to those mothers who used both breast milk as well as formula for their babies.
  • Infants born with a higher birth weight were found to have a higher body fat content three months after birth.
  • In infants that were only breastfed or fed formula as well as breast milk, higher carbohydrate intake by the mothers resulted in higher body fat percentage in the babies.
  • African-American and Hispanic infants had a lower percent of body fat, compared to Caucasian infants three months after birth.

The majority of participants in this study were older, highly educated, non-Hispanic, Caucasian women. The results might vary among other ethnic groups. Also, there were other limitations such as the lack of proper evaluation of the fatty acid components of breast milk, a small sample size and a group that was not very ethnically diverse. Fatty acid composition of breast milk is influenced by the mother’s diet. These are factors that need to be considered in future studies.

This study suggests that the fatty acid composition of a mother’s breast milk may influence the amount of fat in both the mother and her infant after delivery. Though breastfeeding is a healthy practice, mothers need to be wary of what they eat as it is reflected in the composition of breast milk. Mothers exclusively feeding infants gain less weight and have less body fat after delivery. Choosing a healthy diet and restricting certain fatty acids may be beneficial for the health of mothers and their infants. More research needs to be done regarding a breast-feeding mother’s diet, the fatty acids found in her breast milk, and how those fatty acids contribute to child obesity down the road.

For More Information:
Dietary Trans Fatty Acid Intake and Maternal and Infant Body Fat
European Journal of Clinical Nutrition, 2010
By AK Anderson; DM McDougald
From the University of Georgia, Athens, Georgia

*FYI Living Lab Reports Are Summaries of the Original Research.
Tags from the story