Updated

A startling number of parents may be in denial about their youngsters' weight.

A survey found that many Americans whose children are obese do not see them that way.

That is worrisome because obese children run the risk of diabetes, high blood pressure, cholesterol problems and other ailments more commonly found in adults. And overweight children are likely to grow up to be overweight adults.

"It suggests to me that parents of younger kids believe that their children will grow out of their obesity, or something will change at older ages," said Dr. Matthew M. Davis, a University of Michigan professor of pediatrics and internal medicine who led the study, released earlier this month.

"When I see a child that is obese at these younger ages, I take that as a sign of ways nutrition can be improved, a child's activity level can be improved."

Among parents with an obese, or extremely overweight, child ages 6 to 11, 43 percent said their child was "about the right weight," 37 percent responded "slightly overweight," and 13 percent said "very overweight." Others said "slightly underweight."

For those with an obese child ages 12 to 17, the survey found more awareness that weight was a problem. Fifty-six percent said their child was "slightly overweight," 31 percent responded "very overweight," 11 percent said "about the right weight" and others said "slightly underweight."

Dr. Goutham Rao, clinical director of the Weight Management and Wellness Center at Children's Hospital of Pittsburgh, said obesity in children isn't as easy to identify as in adults. "Plus, because of the social stigma, it's not something that parents are willing to admit to readily," Rao said.

The survey of 2,060 adults, conducted over the summer by Internet research firm Knowledge Networks, collected height and weight measurements on the children from their parents, then used that to calculate body mass index.

When a child's BMI was higher than the 95th percentile for children who are the same age and gender, the child was considered obese.

Based on what the parents reported, 15 percent of the children ages 6 to 11, and 10 percent of the children ages 12 to 17, were obese.

The Michigan researchers said that, too, suggests parents underestimate their children's weight. National estimates indicate about 17 percent of U.S. children are obese under the standard used by the researchers.

Dr. Reginald Washington, a member of the American Academy of Pediatrics and part of the AAP's committee on childhood obesity, noted that in about half of cases where a child is obese, one or both parents are overweight, too — and parents can take a pediatrician's concerns as a personal affront.

Experts said doctors need to help parents better understand the health risks of childhood obesity.

"Obesity isn't just something that affects the clothes that you buy or how you are perceived by your friends and your schoolmates," Davis said. "It is something that can have health effects, not only in adulthood but in childhood."