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Getting obese patients to lose weight is tricky to begin with, but doctors may have a bigger battle than they thought: many clinically obese men and women think they’re already at a healthy weight.

In a study of 2,056 obese people in Dallas County (all participants had a body mass index, or BMI, of 30 or higher), researchers asked each participant to look at nine illustrations of bodies, from very thin to very obese. The volunteers were asked to pick their ideal shape along with the one that most closely resembled their own body. About 165 people, or 8% of the group, chose ideal body shapes that were the same or bigger than their own, suggesting a misunderstanding of healthy weight. (More on Time.com: Study: Obese Workers Cost Employers $73 Billion Per Year).

Level of education or money had no bearing on people’s self-assessments, but race did: 14% of black participants had distorted body image, preferring an obese form, compared with 11% of Hispanics and just 2% of white respondents.

People who thought they looked good also said they felt good and were unconcerned about their health. Reuters reports:

People who misperceived their body size were happier with their health, and felt healthier, than those who did recognize their obesity; they were also more likely to think they were at low risk of developing high blood pressure or diabetes or having a heart attack during their lifetimes. In fact, two-thirds of people with body size misperception thought they were at low risk of becoming obese. The study “points to really a lack of understanding about the effects of obesity,” [Dr. Tiffany M.] Powell [of the University of Texas Southwestern Medical Center] told Reuters Health. At the same time, she added, “you walk a fine line, because you don’t want people to necessarily have an unhealthy body image, but you also want people to understand that they need to lose weight.”

A healthy acceptance of one’s own body is undoubtedly critical to good self-esteem. But a lack of awareness of one’s own obesity can lead to undiagnosed obesity-related conditions including sleep apnea, high blood pressure and diabetes. (More on Time.com: Do Parents Discriminate Against Their Own Chubby Children?).



The findings bring to mind a famous 2007 study by Dr. Nicholas Christakis, a professor of medicine at Harvard Medical School, and James Fowler, a political scientist at University of California, San Diego, that found that the more exposure a person had to obesity — in the form of fat friends — the more likely that person was to become obese himself or herself, by 57%. The researchers called it a “contagion effect,” and found that obesity spread more efficiently through networks of friends than through family members or neighbors. TIME reported:

The obvious question is, Why? Spouses share meals and a backyard, but the researchers found a much smaller risk of gaining weight — a 37% increase — when one spouse became obese. Siblings share genes, but their influence, too, was much smaller, increasing each other’s risk 40%. Fowler believes the effect has much more to do with social norms: whom we look to when considering appropriate social behavior. Having fat friends makes being fat seem more acceptable. “Your spouse may not be the person you look to when you’re deciding what kind of body image is appropriate, how much to eat or how much to exercise,” Fowler says. Nor do we necessarily compare ourselves to our siblings. “We get to choose our friends,” says. “We don’t get to choose our families.”

Similarly, the author of the new Texas study theorized that the high rate of obesity in the U.S., where two-thirds of adults are overweight or obese, has helped normalize obesity in the public’s perception. Powell told Reuters: “There is this tendency that if everyone around you looks a certain way, you either want to look that way or you’re comfortable looking the way you are.” (More on Time.com: Explaining the Gender Gap: Obesity Costs Women a Lot More Than Men).

The good news, from a public-health perspective, is that if the contagion effect holds true for weight gain, it may also work in the opposite direction, helping networks of friends lose weight and get healthy.

More on Time.com:

Fitness Tech: 10 Cool Ways to Get in Shape

Study: Can We Tell Our Genes to Make Us Fat?