May 27 (Bloomberg) -- The soaring rates of childhood obesity steadied after 1999, a study shows, providing a ``glimmer of hope'' to researchers.

About 32 percent of children ages 2 to 19 were at risk for being overweight or obese from 2003 to 2006, little changed from 1999, according to data in tomorrow's Journal of the American Medical Association. Of those, 16 percent were overweight or obese and 11 percent were considered the heaviest kids.

The number of overweight and obese children tripled from 1980 to 2002. While the study shows the percentages have stabilized, researchers are waiting for data from 2007 and 2008 to persuade them a change in the rate of childhood obesity has occurred. The findings don't show a decline in the overall number who remain at risk of developing diabetes and heart disease as adults, said David Ludwig, who co-wrote an accompanying editorial.

``After 25 years of extremely bad news about childhood obesity, this study provides at least a glimmer of hope,'' said Ludwig, the director of an obesity clinic at Children's Hospital Boston, in a May 23 telephone interview. ``Without substantial declines in the prevalence, the impact of the epidemic will continue to increase.''

More data collected by U.S. health researchers is needed before they will attribute the plateau in the rate of children who are overweight, now an estimated 25 million to 30 million, to public health efforts to combat the condition.

Many Years

It can take ``many years'' for an obese child to develop a weight-related complication such as Type 2 diabetes, Ludwig said. And it can take years for those complications to become a ``life-threatening event like a heart attack, stroke or heart failure,'' he said.

About 176,500 children and adolescents younger than 20 have diabetes, and 2 million teenagers have blood glucose levels higher than normal, a condition called pre-diabetes, according to the American Diabetes Association.

Researchers from the U.S. Centers for Disease Control and Prevention looked at height and weight measurements from 8,165 U.S. children and adolescents that were taken from 2003 to 2006. They analyzed their body mass index, which is weight in kilograms divided by height, in meters, squared.

The researchers also found that teenagers and 6- to 12- year-olds were more likely to be obese than preschool children, she said. Also, black girls and Mexican-American girls were more likely to be obese than white girls, while Mexican-American boys were more likely to be obese than white boys.

More Evidence

Data from future years will provide a clearer picture of obesity trends in children. The numbers from 2007-2008 won't be available until the end of next year or early 2010, lead author Cynthia Ogden, an epidemiologist at the Centers for Disease Control and Prevention in Hyattsville, Maryland, said in a telephone interview.

``If it shows this leveling-off trend, we can be more comfortable saying that it's leveling off,'' she said. ``There's some reason to be cautiously optimistic.''

Public health campaigns to combat childhood obesity have been sporadic, Ludwig said. National efforts are needed to reduce the number of kids who are overweight or obese, including regulating junk food advertisements to children and providing more money, including insurance reimbursement, for obesity prevention and treatment program, he said.

To contact the reporter on this story: Nicole Ostrow in New York at nostrow1@bloomberg.net.

Last Updated: May 27, 2008 20:26 EDT