In U.S., Obesity Afflicts Even Some of the Tiniest Tots

American kids are becoming obese, or nearly so, at an increasingly young age, with about one-third of them falling into that category by the time they're 9 months old, researchers have found. There are some caveats about the research, however. The infants were not studied recently: They were born about a decade ago. And it's not clear how excess weight in babies may affect their health later in their lives. The study found no guarantee that a baby who's overweight at 9 months will stay flabby when his or her second birthday rolls around.

Still, the study in the January-February 2011 issue of the American Journal of Health Promotion does present a picture of babies and infants who are carrying around a lot of extra weight. The findings also suggest that small changes in an infant's diet can make a big difference, said Dr. Wendy Slusser, medical director of a children's weight program at Mattel Children's Hospital at the University of California, Los Angeles. For example, she said, "if you don't give your kid juice and have them eat the fruit instead, suddenly there's 150 calories less a day that can make a big difference in weight gain over a long term."

The researchers examined federal data about 16,400 children in the United States who were born in 2001. After adjusting the statistics so they wouldn't be thrown off by such factors as high numbers of certain kinds of kids, the study authors found that 17 percent of 9-month-olds were obese and 15 percent were at risk for obesity, for a total of 32 percent. At two years, 21 percent were obese and 14 percent were at risk of becoming obese, the investigators found.