Boston, MAMore months on breast milk as infants may mean fewer pounds on older children and teens later, according to a Harvard Medical School study in the May 16 issue of the Journal of the American Medical Association.
"This study suggests that breast-feeding may prevent obesity later in life," says lead author Matthew Gillman, MD, associate professor at Harvard Medical School and Harvard Pilgrim Health Care. "Our study, along with others, supports the recommendation of the American Academy of Pediatrics to breast-feed infants for the first year."
Obesity has risen dramatically among children and adults. Overweight teens tend to have higher blood pressure and cholesterol, lower self esteem, and on average fare less well in school and earn less as young adults. They also are much more likely to grow into obese adults who face serious health consequences, such as heart disease, diabetes and arthritis.
"Once present, obesity is hard to treat," Gillman says. "For these reasons, prevention is paramount."
Gillman and his colleagues analyzed questionnaires filled out by 8,186 girls and 7,155 boys ages 9 to 14 in the Growing Up Today Study. About 5 percent of the girls and 9 percent of the boys were overweight, defined as having a body mass index (weight divided by height squared) greater than 95 percent of children of the same age and sex. Thats slightly lower than found in the general U.S. population.
When the researchers questioned the mothers all part of the Nurses Health Study II they found that 62 percent of the children were only or mostly fed breast milk for the first six months of life, while 31 percent were only or mostly fed infant formula. Just less than one-half were breast-fed for at least seven months, and about one-third were breast-fed for three months or less. Nationally, less than 30 percent of infants are breast-fed for at least 6 months.