Obesity during childhood often leads to obesity in adulthood. So finding ways to prevent childhood obesity may help prevent today’s children from growing up to be obese adults. Research recently published in The Lancet suggests that children fed only breast milk for the first 6 to 8 weeks of life are less likely to be obese than children fed only formula in that same time frame.

About the study

Scottish researchers examined the health records of 32,200 Scottish children born in 1995 and 1996 who had undergone routine health screenings as part of the Child Health Surveillance Programme. During the screening at 6 to 8 weeks of age, the health worker asked the mother if the baby was breast-fed only, formula-fed only, or fed both breast milk and formula. During a similar screening at 39 to 42 months, the health worker measured the child’s height and weight and calculated the body mass index (BMI)—a measure of appropriateness of weight. BMI that is high indicates overweight or obesity and BMI that is too low indicates underweight.

This analysis included only children who had been either exclusively breast-fed or exclusively formula-fed. Researchers compared the BMI of breast-fed children with the BMI of formula-fed children.

The findings

Breast-fed children were 30% less likely to have BMIs in the obese range at age 39 to 42 months than their counterparts who were fed formula. In calculating these statistics, the researchers accounted for other factors that may affect obesity risk: age, sex, birthweight, and socioeconomic status.

Although these results are interesting, there are limitations to this study. The researchers did not have any information on other risk factors for obesity, such as diet (once they began eating food), parental weight, physical activity and cultural factors. Without this information, the researchers were not able to account for the effects of these factors on the risk of obesity.

How does this affect you?

Does this mean your child will be obese if you don’t breast-feed? Not necessarily. This study merely suggests that breast-feeding may help reduce the likelihood of your child being obese at age 39 to 42 months. However, there are many factors that affect a person’s chances of becoming overweight or obese, such as eating habits and physical activity. And, being obese at 39 to 42 months does not guarantee that your child will always be obese.

The most important thing you can do to help your child maintain a healthy weight is feed him or her a healthful, balanced diet and encourage him or her to be physically active. Breast-feeding may be one more thing you can do to reduce your child’s risk of obesity. But if you choose not to breast-feed, a healthful diet, sound eating habits, and a physically active lifestyle can help your child maintain a normal weight.