URBANA, Ill.In addition to the nutritional content and immune protection provided by breast milk, studies show breast-feeding may also be one of the first positive things a mother can do to help prevent her child from becoming obese.
Among nearly 200,000 four-year olds who had nursed for 12 months were 28 percent less likely to be overweight and children who had nursed for three to six months lowered their risk by 19 percent, says Sharon Donovan, nutritionist at the University of Illinois. The statistics were from an article published in a recent issue of Pediatrics with authors from the Centers for Disease Control.
Donovan says one of the reasons breast-feeding could prevent obesity is the timing of the development of fat cells.
There are three critical times in life when the body normally produces fat cells, says Donovan. Those times are prenatal, in the first year of life and during adolescence. And, unfortunately, once you get fat cells, theyre with you for life.
Donovan says that because the baby self-regulates its breast milk intake and stops nursing when full, breast-feeding may be one way for mothers to have some effect on the number of fat cells their baby produces in that first year of life.
Its almost impossible to force a breast once a baby is satisfied and comes off, says Donovan. But when a baby is formula-fed, its easier for the parent to be concerned if there is a lot left in the bottle and to try to encourage the baby to finish it.
Another major factor is the consistency of breast milk versus formula.
Breast milk is more watery at the beginning of a feeding when the baby is hungriest and the fat content is higher toward the end of the feeding, which contributes to the feeling of fullness, says Donovan. Formula has the same fat and calorie content for the entire bottle so formula-fed babies do not get that satiety signal that helps to trigger the end of the feeding.
Breast-feeding also appears to be beneficial after solid foods are introduced into a babys diet. One study done at the University of California at Davis in California found that when solids were introduced into a babys diet at four to six months of age, breast-fed babies took in less breast milk. But when formula-fed babies began eating solid foods, they consumed the same amount of formula.
Since the first solids introduced are very low in fat rice, fruits and vegetables the primary fat intake would come from the formula or breast milk, says Donovan.
Donovan cautions that babies need fat in their diet. We dont want to send a message to parents to restrict fat intake. But very heavy babies do tend to continue to be heavy throughout childhood. If breast-feeding can help reduce the number of fat cells produced at that time of life, it could be one way to give children a leaner start.
When compared to growth charts that pediatricians use to monitor infant growth, breast-fed babies tend to gain weight rapidly at first and then drop off later in the first year, so some physicians and parents may think that the breast-fed baby isnt thriving.
Donovan says that studies comparing the health of breast-fed babies show that they are healthier than formula-fed infants and that there is no adverse effect on development associated with the slower weight gain during the second six months of life.
Since breast-feeding was the norm during thousands of years of evolution, she says, some experts feel that the pattern of growth of breast-fed babies should be the norm rather than growth charts that were established using data from predominately formula-fed infants.
Cultural beliefs also play a role in childhood obesity. In some cultures, fat babies are healthy babies, says Donovan. Obesity may not carry the same stigma in some minority populations.
Donovan and a graduate student, Pasasie Adedze, are working with University of Illinois Extension and the Head Start program in Chicago to develop culturally appropriate take-home materials that will help families follow the guidelines for healthy eating and exercise that their children learn in the Healthy Moves for Healthy Children program at school.