SATURDAY, Oct. 15 (HealthDay News) -- Many overweight and obese patients seen in hospital emergency departments don't believe their weight poses a risk to their health, and many say doctors have never told them otherwise, a new study finds.

Researchers asked 450 randomly selected patients who were seen in the emergency department at Shands at the University of Florida two questions: Do you believe your present weight is damaging to your health, and has a doctor or other health professional ever told you that you are overweight?

Of those who reported that their weight was unhealthy, only 19 percent said they'd ever discussed it with a health care provider. And only 30 percent of those who reported being told by their health care provider that their weight was unhealthy agreed with that opinion, according to the study.

Researchers also measured their body mass index (BMI) and waist circumference, indicators of body fat.

About 47 percent of obese and overweight men said they believed their weight was a problem, while 53 percent didn't.

Women seemed more attuned to the health issues posed by obesity, said study author Dr. Matthew Ryan, an assistant professor of emergency medicine at University of Florida, Gainesville. About 62 percent of obese or overweight women said their weight was damaging their health.

Among only obese people, or those with a BMI of 30 or above, about 70 percent said their weight wasn't good for their health. Still, that leaves three in 10 obese people who don't see their weight as a health issue -- which it clearly is, Ryan said.

"We see the manifestations of obesity in the emergency department. Obesity is directly linked to other diseases -- hypertension, diabetes, cancers, osteoarthritis, gallbladder disease, heart disease, strokes, and metabolic syndrome," Ryan said. "We see the acute exacerbations of chronic diseases."

Despite the health risks, only 36 percent of overweight or obese men and 50 percent of overweight/obese women reported their doctors had ever discussed weight with them.

"That is disconcerting," said Keri Gans, a registered dietician and spokesperson for the American Dietetic Association. "People need their physician to tell them straight out that if they don't lose weight they are putting themselves at an increased risk of disease. If they are not being told by the doctors, they might think, 'Oh, there is nothing to worry about.'"

The study was to be presented Saturday at the American College of Emergency Physicians meeting in San Francisco. Because this study was presented at a medical meeting, the data and conclusions should be viewed as preliminary until published in a peer-reviewed journal.

Prior research has suggested a disconnect between Americans' weight and their perceptions about their size. A Harris Interactive/HealthDay survey of nearly 2,500 U.S. adults conducted in August 2010 found that 30 percent of those whose BMI put them in the overweight range (25 to 29.9) thought of themselves as normal size. About 70 percent of those who were obese thought they were merely overweight.

Among the morbidly obese, 39 percent thought of themselves as overweight, not obese, the survey found.

A second study Ryan is also slated to present at the conference found that the overweight and obese are being seen in disproportionate numbers in the emergency department.

About 39 percent of people seen in the Florida ER were obese, compared to an obesity rate of 26.6 percent for the general Florida adult population, according to U.S. Centers for Disease Control and Prevention statistics.

Although researchers didn't look at whether obesity-related problems had sent them to seek emergency care, it's safe to assume some were, Ryan said, adding that he believes the numbers would be similar in other ERs.

His research found racial differences in attitudes toward weight. Among overweight and obese black Americans, 53 percent said their weight was bad for their health and 40 percent said doctors had discussed it with them. Among whites, 60 percent of the overweight and obese said their weight was bad for their health and 48 percent had it brought up by a doctor.

About 33 percent of study participants were black, 52 percent were white and the rest were other ethnicities.

Factors that could influence whether or not people discuss their weight with their doctors may include whether they have a primary care doctor or a regular source of care, something which researchers didn't ask. It's also possible that people are ashamed of having been told to lose weight and failing to do so, and so lied and said their doctor had never mentioned it, or simply that it "fell on deaf ears," Gans said.

Ryan recommends that patients leave the ER with referrals to dieticians and other weight-loss specialists, and that primary care doctors make sure to take the time to broach the issue with patients.

Gans agreed. Though emergency room physicians are pressed for time, when patients are sick and worried about their health may be an opportune moment to encourage changes.

"Unfortunately nothing happens until a patient becomes fearful," Gans said. "I see that all too often. I'll ask them, 'Do you need to wait until you have diabetes until you start to lose weight? Do you need to suffer a heart attack? And some people will actually say 'Yes.'"

More information

The U.S. Centers for Disease Control and Prevention has more on overweight and obesity.