Obese people are accurate in assessing their height and weight, but only 15 percent think of themselves as obese, a new study shows.

“I think it’s a misconception in people’s minds about what constitutes obesity,” Dr. Kimberly P. Truesdale of the University of North Carolina at Chapel Hill, the study’s lead author, told Reuters Health. “I think a lot of people when they think about obesity they think of someone that’s extremely obese, 400 pounds or so.”

In fact, she pointed out, a woman who is 5 feet 4 inches tall would be classified as obese if she weighed 175 pounds. “I don’t think that’s the image most people have of obesity,” said Truesdale, who reported her findings Tuesday in San Francisco at the Experimental Biology 2006 meeting.

Truesdale and her team surveyed 104 people, of whom 31 were of normal weight, 40 were overweight, and 33 were obese. They were asked to report their weight and height; how they would define their own weight status; and how much they would need to weigh in order to be obese.

The researchers measured participants’ height and weight and calculated their body mass index (BMI), and then calculated the BMI based on the participants’ own reports of their height and weight.

Ninety percent of normal weight people and 85 percent of overweight and obese individuals reported heights and weights that resulted in a BMI in the same category as their actual BMI.

But while 71 percent of normal weight people and 73 percent of overweight people identified their weight category correctly, just 15 percent of obese adults did.

Nearly three quarters of the obese subjects classified themselves as overweight, while 12 percent said their weight was normal for their height.

Even among a group of her colleagues who work in the obesity field, Truesdale noted, many don’t know the weight at which they themselves would be classified as obese.

Denial as well as skewed perceptions of what constitutes obesity may make people reluctant to define themselves as obese, she added. “Just the term obesity has a lot of negative images associated with it. People might just not want to put that label on themselves.”

However, the researcher said, it is important for a person to recognize if they are obese, because being obese carries a higher risk of health problems than being overweight.

SOURCE: Experimental Biology 2006.