Rapid Weight Gain During Infancy Could Lead to Obesity

Everywhere you turn these days there’s frightening news about the obesity epidemic among American children. According to the latest statistics, an estimated 15 percent of children and adolescents ages 6-19 years are obese, and as that number continues to rise, so does the debate over its cause. Some argue that today’s kids stay indoors too much watching television and playing video games; walking less and generally living an unhealthy lifestyle. Others argue that children today are getting many more calories than in previous generations through an unfit diet of convenience foods. But researchers now suggest the risk of obesity may actually begin much earlier—during infancy.

Dr. Elsie Taveras of Children’s Hospital Boston and her colleagues from Harvard and Harvard Pilgrim Health Care tracked 559 children taking part in Project Viva, an ongoing Boston-based study of more than 2,000 pregnant women and their children. They measured each child’s weight and height at birth, at 6 months and again at 3 years. Even after adjusting for factors such as being born premature or underweight, the link between rapid infant weight gain and obesity by age 3 was “striking,” said an HMS release. According to the study estimates, an infant weighting 18.4 pounds at six months would have a 40 percent higher risk of obesity at age 3 than an infant of the same birth weight who weighed 16.9 pounds at six months. “There is increasing evidence that rapid changes in weight during infancy increase children’s risk of later obesity,” Taveras said in a statement. “The mounting evidence suggests that infancy may be a critical period during which to prevent childhood obesity and its related consequences.”

The study did not look at what causes rapid weight gain in some infants, but Taveras said excessive weight gain during pregnancy could be a factor. It could also be the quality of the diet after weaning or parents not responding to their infant’s hunger or satiety cues. Even beliefs that baby fat will go away could be affecting the way parents think about feeding their children. “There are a lot of parents who think children who top the growth charts are healthier than children who don’t,” she said. “The (study) results could really be a wake-up call that we might have some misconceptions about what healthy growth is.”

However, some pediatricians are skeptical of the findings. Dr. Samuel Grief, associate professor in clinical family medicine at the University of Illinois at Chicago and obesity expert, said he wasn’t convinced that a child could be predisposed to obesity so young. “I take this as another piece of the puzzle,” he said. “Parents should model the behavior children will learn the rest of their lives—eat sensibly, with variety and with common sense, without developing obsessions.”
 
Dr. Nancy Welch, health director for the city of Chesapeake, said the study goes against traditional thinking that children’s weight is best addressed after children learn to walk, a point in time when they often burn off so-called baby fat. She said the study raises questions on the subject and hopes it encourages more study. “I think it’s wise to see what other studies show.”

On average babies double their birth weight by 4 months; triple their birth weight by 12 months and will be around four times their birth weight by 2 years. The most rapid period of growth is between 2 weeks and 6 months of age, after which the rate declines. “At present, most guidelines around obesity management recommend that we start assessment and treatment of children after the age of 2,” Taveras said. But “we need to start our preventative methods when children are much younger. Even in the first couple of weeks of life, we can start guiding parents about how to prevent rapid weight gain in their infants.”

The study is to be published in the April issue of Pediatrics.