Babies who gain weight rapidly during their very first week of life may be more likely to be overweight as young adults, according to a new study. The research suggests that the first week may be a critical period for setting lifelong patterns of body weight.
Researchers from The Children's Hospital of Philadelphia, the University of Pennsylvania and the University of Iowa studied 653 adults, ranging in age from 20 to 32. The subjects, all of whom were white, had been measured as newborns while participating in infant formula studies in Iowa. Those who had gained weight more rapidly during their first week were significantly more likely to be overweight decades later.
The research appears in the April 19 issue of Circulation, the journal of the American Heart Association.
"Our main finding was that rapid weight gain during the first week of life in this population of healthy, European-American, formula-fed infants was associated with being overweight two to three decades later," said lead author Nicolas Stettler, M.D., M.S.C.E., a pediatric nutrition specialist at The Children's Hospital of Philadelphia. "It suggests that there may be a critical period in that first week during which the body's physiology may be programmed to develop chronic disease throughout life."
"Our findings also point toward new potential targets for preventing obesity," he added. "If these results are confirmed by other studies, they may lead to interventions in newborns to help prevent long-term development of obesity." Dr. Stettler explained, however, that such interventions have not yet been developed, and it is premature to make recommendations about specific targets for optimum weight gain.
"Normal weight gain is desirable for infants," he added. "Babies double their birth weight during the first four to six months. During the first week of life, however, a too-rapid gain in weight may increase the risk of future weight problems." After adjusting for other factors, Dr. Stettler's team found that each additional 100 grams of weight gained during the first eight days increased a baby's risk of becoming an overweight adult by about 10 percent.
The current research builds on several previous studies by Dr. Stettler and his collaborators focusing on rapid weight gain in infancy. They found that rapid weight gain during the first four months increased the risk of being overweight at age seven. They also found a higher rate of obesity at age 20 among African Americans who gained weight rapidly during the first four months.