“Fat? Not my kid!” That reaction, according to researchers at the University of Michigan’s C.S. Mott Children’s Hospital, was common among more than 2,000 parents surveyed this year as part of the National Poll on Children’s Health.

The problem was that 40 percent of youths ages 6 to 11 whose parents described them as “about the right weight” were actually obese.

Fewer than 10 percent of parents whose children were obese said they were “very concerned” about their child’s weight. Overall, 25 percent of children whose parents were polled were classified as overweight or obese.

Researchers led by physician Matthew M. Davis found other disparities as well: Forty-one percent of African Americans said they were very concerned about their children’s obesity, compared with 30 percent of whites and 17 percent of Hispanics. Parental concern about a child’s obesity was lowest in the Midwest (13 percent) and highest in the Northeast (37 percent).

Experts say the study underscores the disconnect between public awareness of childhood obesity as a public health problem and the ability to recognize it in one’s children. In recent years some pediatricians have called on doctors to take a more direct approach with parents in addressing the issue, which some physicians have avoided mentioning because they feared offending families.