Breast-feeding infants may reduce their risk of becoming obese children, even if the mother is obese or has diabetes, according to a study led by a researcher at the University of South Carolina's Arnold School of Public Health.
The findings contradict an earlier, smaller study that found that children who had been breast-fed by mothers with diabetes had poor glucose tolerance, a precursor to diabetes, and excessive weight gain, said the University of South Carolina's Dr. Elizabeth Mayer-Davis, the lead researcher on the study that involved scientists from Harvard University and Brigham and Women's Hospital in Boston.
"In contrast to the earlier study, we were able to include mothers in our study who didn't have diabetes, as well as those who did, and our sample size was significantly larger," Mayer-Davis said.
The study was conducted at the Harvard School of Public Health and included more than 15,000 boys and girls between the ages of 9 and 14. The researchers found that those who were breast-fed during the first year of life were less likely to become obese as they got older, regardless of whether their mothers were overweight or had diabetes.
The researchers believe there are several reasons why breast-fed babies may be less likely to become overweight. Nursing mothers may be more likely to respond to the baby's natural cries for food, rather than having them on a schedule. Breast-fed babies also may be more likely to stop eating when they are full, in contrast to bottle-fed babies, who are given a specific amount of formula and encouraged to finish whatever is in the bottle. And the nutritional composition of breast milk is different than formula and actually changes while the infant is nursing. The infant's biological response to breast milk may impact later risk for gaining excess weight, Mayer-Davis said.
"Breast-feeding can get children on a healthy track in life, particularly when the family emphasizes continued good nutrition and regular physical activity as part of their lifestyle," she said.
Mayer-Davis said the study points to the importance of encouraging breast-feeding, especially in families with a family history of obesity, diabetes and other related health factors, such as high blood pressure and cardiovascular disease.
"By encouraging breast-feeding, this means encouragement by physicians, nurse practitioners and other healthcare providers," she said. "But it also is extremely important to have support among family members, friends and employers who can make accommodations for women who need to take time to use their breast pumps."