Starting solids too early may increase obesity risk

The study's authors, Susanna Huh and Sheryl Rifas-Shiman

The American Academy of Pediatrics (AAP) released a new study online today that reinforces its previous recommendations that parents wait to introduce solid foods to their babies until they are at least 4 months old. The study was co-led by Susanna Huh, MD, MPH, of Children’s Hospital Boston’s Division of Gastroenterology and Nutrition, and Sheryl Rifas-Shiman, MPH, a research associate at Harvard Medical School/ Harvard Pilgrim Health Care Institute.

Huh and Rifas-Shiman’s research followed 847 children from birth, and found that among formula-fed infants, those who were given solid food before 4 months were six times more likely to be obese by the time they turned 3 than those whose parents waited until 4 or 5 months to feed them solids. Interestingly, the timing of solid food introduction didn’t seem to be related to the risk of childhood obesity in children who were breastfed.

With almost 60 percent of American babies being fed infant formula instead of breast milk by the time they’re 6 months old, the study may have important implications for the future of obesity prevention.

“As researchers, our ultimate goal is to identify the risk factors of obesity as early in life as possible,” Huh says. “Once obesity has been established in a child, it becomes very hard to treat. From a public health standpoint, early identification and prevention of the condition is very important to combating the growing number of obesity cases in this country.”

Susanna Huh, MD, MPH

Why an early introduction of solid food seems to affect formula-fed infants so much more than breastfed ones isn’t clear, but one theory is that breastfeeding may train infants to regulate their own food intake and may train mothers to better recognize hunger and fullness cues in their children. Of the study participants, 8 percent of the breastfed children were given solid foods before 4 months of age. In contrast, 33 percent of the formula fed subjects ate solid foods prior to the recommended age. According to researchers, these percentages mirror the national averages.

“Based on what we’ve seen in our research, we would recommend that parents of formula-fed children adhere to AAP guidelines and not feed their children solid foods until they are at least 4 months old,” Huh says. “Increasing adherence to these recommendations may provide one public health strategy to lower the rates of obesity in American children, by helping to prevent obesity from developing in the first place.”

Check Thrive tomorrow when Claire McCarthy, MD, will offer suggestions for the parents of young children on how they can proactively address childhood weight gain before it becomes a problem.