Overweight adults who fail to recognize excess pounds less likely to eat healthy and be active

About one-quarter of overweight and obese adults do not recognize that they are carrying excess pounds and, in fact, many consider themselves underweight or at an ideal weight. These individuals often do not try to eat healthier, lose weight, or get adequate physical activity, according to a new study from Harvard School of Public Health (HSPH) and Duke University researchers.

The study, led by Dustin Duncan, a doctoral student in social epidemiology at HSPH, was published online March 22, 2011, by the International Journal of Behavioral Nutrition and Physical Activity. Duncan also is an Association of Schools of Public Health/Centers for Disease Control and Prevention (CDC) Fellow at the Harvard Prevention Research Center on Nutrition and Physical Activity.

The findings have significant implications for public health in the U.S., where nearly 70 percent of Americans are considered overweight or obese.

The researchers, including senior author Gary Bennett of Duke University, analyzed data on thousands of individuals enrolled in the CDC’s 2003-2006 National Health and Nutrition Examination Survey (NHANES).

“Our study is among the first to show that weight misperceptions hinder weight loss and control, which is important on its own but also because these data are nationally representative,” Duncan said in a press release. “Given that our study shows that these misperceptions are related to the risk of obesity, it is imperative for us to understand why these misperceptions exist in the first place in order to determine the best strategies for preventing and reducing them,” he added.

The clothing industry can help by eliminating “vanity sizing” or size inflation, the researchers wrote. In vanity sizing size numbers drop over time; for instance size 14 may become size 10. The investigators also believe social norms related to weight could contribute to the misperceptions. “We plan to investigate some of these hypotheses in follow-up studies,” Duncan said.

Read the IJBNPA study

“1 In 4 Overweight or Obese Adults Don’t Believe They Have a Problem” (Duke University press release)