It’s that time of year again when legions of overweight Americans commit — or recommit — to exercising and shedding pounds to improve their health. But what if exercise alone were enough? What if you could be fit and fat? Some research suggests your size doesn’t matter as long as you exercise regularly. But new findings on this controversial issue paint a different portrait of a healthy body.
A recent study of more than 5,000 men and women found that being overweight does indeed affect your health, regardless of how much time you clock at the gym.
“The main message is that you need to be both fit and lean,” says study author June Stevens, a professor of nutrition and epidemiology at the University of North Carolina in Chapel Hill. “Being fit is not enough and being lean is not enough. You need to be both to maximize longevity.”
From 1972 to 1976, when study participants were in their mid-40s on average, they took treadmill tests to determine their cardiorespiratory fitness levels and researchers measured their body mass index, an assessment of body size that takes into account height and weight. Based on the results, the subjects were grouped into four categories — fit, unfit, fat or not fat — and followed until 1998.
Compared with participants who were fit and not fat, those who were unfit and fat faced the greatest increased risk of death — 57 percent for women and 49 percent for men. While exercise helped promote longevity in the fat group, it did not compensate for all the negative health effects of the excess weight, according to findings published in the American Journal of Epidemiology.
And not surprisingly, people who were thin but out of shape also had a shorter life span than their lean, active counterparts.
The findings offer encouraging news to overweight individuals hoping to improve their health: Exercise can help.
But weight still matters. “If you’re overweight and you’re fit, that does not mean you don’t need to lose weight,” Stevens says.
'Too much focus on BMI'
Not everyone agrees.
“There’s too much focus on BMI and body weight,” says epidemiologist Steven Blair, president and CEO of the Cooper Institute, a non-profit organization in Dallas that studies fitness and other health issues.
He says most studies on the dangers of obesity have not adequately accounted for the impact of exercise.
“Don’t just look at a person’s shape,” says Blair, “and conclude that they’re unhealthy or that they’re healthy.”
But that’s often what health professionals do, he says. Doctors routinely exhort overweight patients to lose weight when they may be better off focusing more on exercise and less on the bathroom scales, he maintains.
Unlike Stevens’ research, work by Blair and colleagues has suggested that fitness may be a much more important factor in longevity than fatness. In fact, a 1999 study involving nearly 22,000 men followed for an average of eight years concluded that being fit appeared to negate the health risks of obesity that can lead to an early death. When it comes to living a long life, results indicated, it’s better to be fit and fat than thin and sedentary.
And it doesn’t take all that much exercise to make someone fit, according to Blair, who says that the federal government’s recommendation of just 30 minutes a day of moderate exercise, such as walking, on most days can do the trick.
Blair cites himself as a member of the fit-and-fat crowd. Self-described as “short and stocky,” he exercises a lot — running about 45 minutes daily for the last 35 years — and follows a healthful diet.
“There’s no question I’m overweight. So all that exercise hasn’t been enough in my case to prevent weight gain that occurs with aging,” Blair says.
'A rare bird'
Still, most people who are fat are far from fit, points out Dr. JoAnn Manson, chief of preventive medicine at Brigham and Women’s Hospital and a professor of medicine at Harvard Medical School.
“A person who is both fit and fat is a rare bird,” she says. “Most Americans are sedentary.”
Government statistics show that about two-thirds of Americans do not get enough physical activity and a similar number is overweight or obese. Both a sedentary lifestyle and obesity are linked to heart disease, cancer, type 2 diabetes and other health conditions, Manson notes.
She says the new study by Stevens is consistent with the majority of previous research, including work of her own.
“Most studies have suggested that obesity and sedentary lifestyle are independent risk factors and that although being fit can reduce the health risks of obesity, it does not fully eliminate them,” she says. “It is inappropriate to give the public-health message that obesity doesn’t matter as long as you exercise.”
Fitness specialist Dixie Stanforth, a spokesperson for the non-profit American Council on Exercise and a lecturer at the University of Texas at Austin, agrees with Manson that it’s uncommon for someone to be both fit and fat.
“Most people who exercise and eat a healthy diet will lose weight,” says Stanforth.
But just how thin people get can depend on how their bodies operate, she says. “I don’t think that everyone has the genetic capacity to be lean.”
In other words, we’re not all programmed to be as svelte as Nicole Kidman or as buff as Brad Pitt. At the same time, though, we’re not intended to be a nation of people who are becoming more and more obese each year.