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Last Updated: July 16, 1999
London - Babies are less likely to grow up to be fat children if they are fed breast milk exclusively, a new study shows - providing powerful ammunition for the campaign to encourage mothers to choose the breast over the bottle.
German scientists say their findings, published today in the British Medical Journal, are the result of the largest study to date investigating the link between breast-feeding and subsequent obesity.
The findings suggest breast-feeding could turn out to be a powerful strategy for fighting the spiraling level of childhood obesity, said Robert H. Eckel, chairman of the American Heart Association's nutrition committee, who was not connected with the study.
The study, which tracked 9,357 children in Bavaria, found that the longer babies were breast-fed exclusively before being switched to formula or food, the lower their chances of starting school overweight or obese.
About 60% of mothers breast-feed in industrialized countries, but most give up by the time their babies are 2 months old.
The German study found that infants given only breast milk until they were 3 to 5 months old were more than one-third less likely to be obese by age 5 or 6 than babies given only formula from the start.
Those breast-fed exclusively for 6 months to a year fared even better - they were 43% less likely to be obese, the study found.
Breast-feeding beyond a child's first birthday was better still, giving babies a 72% lower chance of turning out to be obese children, the researchers said.
Even just some breast milk proved to be better than none, according to the study. Children who were breast-fed for only the first month or two of their lives were 10% less likely to be obese by the time they entered elementary school.
Besides being more likely to be obese, bottle-fed children also had a greater chance of being simply overweight by elementary school, the study said. As with obesity, the risk diminished the longer breast-feeding continued into childhood.
The researchers took into account several factors that could have skewed the results, such as eating habits, socioeconomic class, birth weight, parents' and siblings' ages, how long the children played outside and whether they had their own bedrooms.
What is not clear from the study is how much of the children's weight problem was due to an inherited tendency to be fat.
Eckel said genetics might be responsible for a small percentage of the cases but could not be the total explanation because so many children were studied.