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Obesity may not be real culprit

Diabetes, not extra heft, is the killer, a study finds. Maybe you can be fit and fat.

October 02, 2006|Susan Brink | Times Staff Writer

Fit and lean is good. Fit and skinny is not so good. Unfit and lean is worse than fit and fat.

And fit and fat ... well, it's a whole lot better than unfit and fat, but can it be healthy? To this day, the controversial question has physicians, nutritionists, public health officials and diet gurus choosing sides.

Now a new study has added some heft to the "fit and fat is fine" argument by reporting that diabetes, not obesity, increases the risk of illness and early death.

The study, published last week in the journal Critical Care, analyzed data from more than 15,000 participants of a government-funded study that has been running since 1987. The researchers looked at the risk of organ failure and death among overweight and obese people with diabetes, and compared it with that of all people with diabetes.

They found that diabetes, whatever a person's weight, increases the risk for future organ failure, illness and early death.

This is not surprising because the disease is well-known to be a risk factor for many health problems, including heart disease, kidney failure and blindness.

But the authors also found that being either overweight or obese, without diabetes, added no additional risk of these outcomes.

People who are overweight (meaning they have a body mass index, or BMI, of 25 or more) do have an increased risk for diabetes, and the risk increases with size.

Carrying extra pounds, by some estimates, increases the risk for diabetes five- to ten-fold if a person is overweight and even more if they are obese.

"There's a continuum," says Dr. Greg Martin, professor of medicine at Emory University in Atlanta and a coauthor of the study.

But even so, most overweight and obese people are not diabetic, points out Dr. David Mannino, senior investigator of the study and professor of pulmonary and critical care at the University of Kentucky. He could lose a few pounds himself, he admits.

"I'm almost 50. I've got a BMI of 26, which means I'm somewhat overweight," he says. "But I'm not diabetic, I exercise, and I'm healthy."

The idea that a person can be both fat and fit gained support in 1997, with a study published in the Journal of the American Medical Assn. by researchers at the Cooper Institute in Dallas. They looked at records of more than 25,000 men and found that those who were unfit and lean had a death rate nearly three times higher than that of men who were overweight and moderately fit.

In 2003, the researchers followed up that study with another of more than 9,000 women, reporting that unfit women of any size had a 48% higher risk of death than moderately fit women of any size.

Few would argue that being overweight is good for health. But evidence is accumulating that a good diet and regular exercise can mitigate some of the damage caused by too much body fat, and that being too thin is unhealthy too.

That's what Katherine Flegal, a researcher at the Centers for Disease Control and Prevention, found in a study published in the Journal of the American Medical Assn. last year.

Looking at a representative sample of the entire U.S. population (from a government-collected data set known as the National Health and Nutrition Examination Survey), she found that obesity was associated with more than 100,000 excess deaths. Being underweight was associated with more than 33,000 excess deaths.

But being overweight, and not obese, was not a risk factor for early death.

"The debate is still going on," says Joanne Ikeda, co-director of the Center for Weight and Health at UC Berkeley. "Both sides are digging in their heels. I'm a proponent of health at any size."

Instead of focusing on weight or BMI (a measure of body fat based on height and weight), she says people should focus on a wide variety of disease predictors, such as blood pressure and cholesterol level, and use diet and exercise to control those risks -- even if changing eating and exercise patterns doesn't result in weight loss.

"We know that walking briskly for 20 minutes a day reduces the risk of developing diabetes, even if it doesn't result in weight loss," she says.

Similarly, eating a diet rich in fruits and vegetables, with moderate amounts of low-fat dairy products and lean meat, poultry and fish can lower blood pressure regardless of weight, even if it doesn't lower the needle on the bathroom scale, according to a long-term federal project known for short as the DASH study.

But the message is tricky, Martin says. Americans are becoming increasingly portly, and many overweight people will become diabetic, especially if they eat a high-fat diet and combine it with a sedentary lifestyle. "You don't want to tell people that it's OK to be chunky," he says.

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