Though many people connect poor health with excess weight, the two don’t always go together. Even as most health experts say that fat fuels the onset of diseases such as hypertension, diabetes, heart disease, stroke, some cancers and arthritis — and with the federal Centers for Disease Control and Prevention linking obesity to 9% of health care costs — folks behind the Health at Every Size program say that such statistics don’t actually take healthy fat people into account.

One of the largest studies to support their claim that weight doesn’t determine health is the National Health and Nutrition Examination Survey, published in August 2008 in the Archives of Internal Medicine. The NHANES study looked at 5,440 adults, assessing weight and metabolic health indicators such as blood pressure, cholesterol, blood lipids, blood glucose, insulin resistance and other diabetic markers. Although those in the normal weight group were healthiest, metabolically speaking (76.5%), nearly one out of four fell into the abnormal range. In the overweight group, more than half (51.3%) were metabolically healthy; as were nearly a third (31.7%) of the obese group.

The researchers’ conclusion: Although fat people are more apt to be metabolically unhealthy, plenty of fat people are healthy, and plenty of thin people are unhealthy.

“You can’t know just based on a person’s size whether that person has good or poor health habits,” says Linda Bacon, a professor of nutrition at City College of San Francisco and author of “Health at Every Size: The Surprising Truth About Your Weight” (Ben- Bella 2008). “Some people are heavy and unhealthy, and some are heavy and health- y.”

So instead, folks behind the Health at Every Size program, which Bacon and many others are researching and promoting, advocate intuitive eating — that is, teaching people to tune in to their hunger signals

By doing so, they say, people are more likely to eat when they’re hungry, not because it’s lunch time, and to stop when they’re satisfied not stuffed. These advocates also encourage people of every size to embrace physical activities that feel good and that they enjoy. “The advice applies whether you’re 100 pounds or 500 pounds,” Bacon says.

Bacon and her colleagues tested the Every Size theories with funding from the National Institutes of Health, and published their findings in the Journal of the American Dietetic Assn. in 2005.

The study tracked 78 obese women between the ages of 30 and 45. Half the group participated in the Every Size program, and half participated in a traditional weight-centered diet. Two years later, researchers found that both groups weighed the same as when they started. (Although the diet group’s members had lost weight at the six-month checkpoint, they’d gained it back by the two-year mark.)

However, unlike the diet group, the Every Size group lowered its blood cholesterol and blood pressure and maintained those reductions for the entire course of the study. The dieters did not lower their cholesterol at any point, and did not maintain the lowered blood pressures they achieved in the first six months.

Similarly, levels of depression improved and self-esteem increased for both groups at first. However, only the Every Size group sustained the positive mood and self-esteem scores two years later. The dieters’ depression levels fell back to near original levels, and self-esteem scores were worse at follow up.

“Increasing evidence supports the belief that diseases associated with obesity can be reversed or minimized through lifestyle changes, even without weight loss, and people can improve their health while remaining obese,” says Bacon, who — incidentally — at 5 feet tall and 105 pounds has a low BMI of 20.5. For heavy people who have tried unsuccessfully to lose weight, a health-centered rather than a weight-centered approach may help them get healthy if not thin.

Not all health experts are so quick to give heavy people a hall pass.

“It’s dangerous to go down the path that says it’s OK to be obese,” says Janet Pregler, director of the Iris Cantor UCLA Women’s Health Center and a professor of clinical medicine at the David Geffen School of Medicine at UCLA. “We know that obesity is a detriment to health.”

But even Pregler acknowledges that obesity is very difficult to treat and may never be fully resolved. “Weight-loss interventions are so ineffective,” she says. “So I agree that if you’re obese and doing what you can to reduce or manage other risk factors, that’s an important goal.”