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Fat and Fit: Who Says You Can't Be Both?

If health advice were a symphony, everybody from the horn section to the violins would be playing the same note, and “obesity” would be its name.

The symphony reached a crescendo last summer, when the U.S. Obesity Prevention Act of 2008 was introduced with alarm bells. Announcement of the initiative included words like “hurricane,” “emergency,” “havoc” and “dire.” The epidemic would doom the nation’s children and kill the rest of us while soaking up more resources than the health care system has to offer. But lately, another quiet little melody has been playing. This tune goes like this: Why don’t you stop sitting around calculating your BMI—body mass index—and go take a nice long walk?

The BMI is a calculation of body fat based on height and weight. To calculate your BMI, you can go to a handy online calculator devised by the National Institutes of Health. Any number below 25 is “normal,” “overweight” is 25-30 and “obese” is over 30. The number is supposed to tell us our fate. For most of us, the message has become dire and overly simplistic: Lose weight or die.

Even before last summer’s pronouncement of an obesity emergency, researchers had reported different findings in a study published in December 2007 in the Journal of the American Medical Association (JAMA). The study found that fitness—in this case the ability to walk quickly on a treadmill for a few minutes or longer—was a better predictor of who would die, and when, than BMI.

The study followed 2,600 adults over age 60 for 12 years. Participants were asked to walk on a treadmill at a quick walking pace, with a gradually increasing incline. Based on the results of the treadmill test, they were then put in five fitness categories, from least to most fit.

Researchers found that the least fit, regardless of BMI, were four times more likely to die during the course of the study than the most fit. But the most surprising difference in mortality was between the least fit group and the one just above that, who were half as likely to die during the study. In other words, just a little fitness could be twice as good as no fitness at all.

When the results were adjusted for other factors, such as smoking and age, fitness still mattered most.

So is it fitness, rather than fatness, that really counts? “That’s what we keep finding,” says Steven N. Blair, a coauthor of the JAMA study, and professor of exercise science and of epidemiology and biostatistics at the Arnold School of Public Health at the University of South Carolina. Clinical trials under way on the benefits of fitness will likely show that physical activity preserves brain health, too, Blair adds, meaning fitness may also lower the risk of dementia.

To be sure, nobody is saying that obesity is desirable. Overweight and obese individuals may have a harder time moving around, face all kinds of bias and discrimination, and are more likely to have risk factors for cardiovascular and other diseases. But being fat isn’t the same thing as being unhealthy, and it doesn’t have to mean early death.

Another study of 5,400 adults, published in August 2008 in the Archives of Internal Medicine, found that fully half of overweight and one-third of obese participants were “metabolically healthy,” meaning they had few, if any, risk factors for heart disease, such as high blood pressure or low levels of “good” cholesterol. On the other hand, about a quarter of “normal”-weight people were metabolically unhealthy and exhibited cardiovascular risk factors. This study did not measure the fitness levels of the participants.

“I’m still not convinced that fat doesn’t matter,” says Rachel Wildman, a researcher at Albert Einstein College of Medicine in New York and a coauthor of the Archives study. “But long-term, the incorporation of physical activity is easier to accomplish” than losing weight through dieting. It’s still possible, Wildman says, that exercise and weight loss are both important.

The idea that the rotund among us can be healthy is a hard one for some people to accept. Readers of a New York Times blog on the subject were often angry, pointing out, among other things, that twice as many fat people as slim suffer health problems tied to their weight.

But by concentrating only on fat, health care practitioners could be missing an important chance to show people another path to better health. Increasingly, the idea of “dieting,” with its counting of carbs and calories, its portion control and rigidity, is falling by the wayside in favor of a more balanced approach to disease prevention.

Blair, at 69 among the most celebrated medical experts on fitness and health, walks the walk. A self-described “short, fat, bald guy,” Blair runs about 25 miles a week, sometimes admitting to a “run-walk” if the hill is steep. Some days he eats too much, he says, but “I try every day. I don’t say we should discourage people from losing weight. But the bottom line from a public health standpoint is to concentrate on behaviors: Don’t smoke, do some physical activity five days a week, and eat a healthy diet.”

The toughest physical trainer he knows, he says, is his three-and-a-half-year-old grandson, who loves chasing his grandparents around the yard. Losing weight on a diet “might get you a date or more room in the airline seat,” says Blair. But for some people, it’s too much pain for too little health gain.

One of the struggles for overweight people is overcoming the embarrassment they sometimes feel being active in public. Sherry Mayrent, 57, of Boston, loves to ride her bike on the Charles River bike path. But at 5’3” and 265 pounds, she felt intimidated by the slim young folks whizzing past her on their way to work. “Then I thought, ‘Wait a minute! These people are half my age and half my size! I’m not doing so badly.’ ”

Mayrent credits her increased confidence to several stays at a Vermont spa called Green Mountain at Fox Run, one of an increasing number of health retreats that focus on physical activity, self-knowledge and sound nutrition. “It was a safe place to get active,” she says. “I could try things without looking like an idiot.” She first concentrated on strengthening the core muscles in her trunk, which she discovered was the secret to gaining strength and fitness in the rest of her body. Then she moved on to generalized strength training and aerobics. “It was amazing, it totally changed my life,” she says.

Her knees still hurt and she continues to receive treatment for high blood pressure and asthma. But recently, she says, she walked up a familiar hill “for the first time without wheezing myself to death.”

Mayrent hasn’t stopped trying to lose weight—regardless of her fitness level, obesity raises the risk for diabetes, heart disease and stroke, and some research still links obesity to a higher risk of death. But she’s no longer the one who stays behind while others walk to get the car, and she can get down on the ground and play with her grandkids. She hasn’t lost a pound, but the fitness payoff came last year when she completed a 26-mile bike ride at a charity event in Boston.

Mayrent’s advice? “You have to do things you love to do.”

Linda Greider is a freelance writer who lives in Washington.

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