Many parents of children classified as overweight or even extremely overweight do not perceive their child as being excessively heavy, with some wrongly believing that their child is “about the right weight,” new research suggests.

In addition, if the parent fails to perceive a weight issue, odds are the child will also fail to see a problem.

These findings are “important” and “troublesome,” the researchers say in their report in the medical journal Diabetes Care, because recognition that a child is overweight is a critical first step to making diet and lifestyle changes to promote weight loss.

Dr. Asheley Cockrell Skinner of the University of North Carolina at Chapel Hill and colleagues interviewed 104 adolescents with type 2 diabetes and their parents about perceptions of the adolescents’ weight, diet and exercise habits.

To gauge weight perceptions, the teens and their parents were asked if they thought the adolescents were “very overweight, slightly overweight, about right, slightly thin, or very thin?”

While 87 percent of children were overweight by accepted standards, “only 41 percent of parents and 35 percent of adolescents considered the adolescent to be ‘very overweight’,” the team reports.

Among parents who felt their child’s weight was “about right,” 40 percent had children whose body mass index (BMI) was at or above the 95th percentile. More than half (55 percent) of the adolescents who said their weight was “about right” had a BMI at this level.

Adolescents were more apt to underestimate their weight when their parents also underestimated weight than when their parents accurately perceived the child’s weight.

For parents and adolescents, underestimating the adolescents’ weight was associated with poorer diet and exercise habits.

“Addressing misperceptions of weight by adolescents and their parents may be an important first step to improving weight in these patients,” conclude the researchers.

SOURCE: Diabetes Care, February 2008.