"We've studied this from many perspectives in women and in men and we get the same answer: It's not the obesity -- it's the fitness," Blair said. "Fitness can substantially reduce, if not eliminate, the high risk of being obese."
Ikeda tests people to see if they are "metabolically healthy." If she spots warning signs, she recommends exercise and a nutritious diet, but with the goal of making people fitter, not necessarily thinner.
"I wouldn't mind losing weight, but I know if I go on a weight-loss diet I'll just spring right back," says Jude Mathews, a librarian. "What is really dangerous is yo-yo dieting, not to mention destroying people's self-esteem."
(John Gress For The Washington Post)
Plan to Be Successful (The Washington Post, Nov 30, 2004)
N.Y. Creates Site on Obesity, Insurance (Associated Press, Nov 27, 2004)
CDC Admits Errors in Obesity Risk Study (Associated Press, Nov 24, 2004)
CDC Study Overestimated Deaths From Obesity (The Washington Post, Nov 24, 2004)
CDC Admits Errors in Obesity Risk Study (Associated Press, Nov 23, 2004)
"What weight-loss programs promote are diets that are so low in calories that people are constantly fatigued, and then they have a hard time getting out there to exercise, which is really what will help them," Ikeda said. "How stupid is that?"
The focus on weight loss is especially misguided because most people simply are unable to lose substantial weight and keep it off, Ikeda, Blair and others say.
"I'm a short, fat guy myself," Blair said. "I'd like to be thinner. I'm not saying people shouldn't try to lose weight. But we're not getting anywhere with all the focus on obesity -- shouting from the rooftops how bad obesity is. So if the strategy is not working, it seems to me we ought to be thinking about different strategies."
Becoming fit is often much more attainable, Blair and others say.
"If you take a fat person who has all these health problems that have been labeled weight-related health problems and put them on an exercise program and clean up their diet, their health generally improves yet their body weight hasn't budged much," said Glenn A. Gaesser, a University of Virginia physiologist who wrote "Big Fat Lies: The Truth About Your Weight and Your Health," a book that questions many assumptions about obesity. "It's far easier to get a fat person fit than to get a fat person thin."
Mathews, the Illinois librarian, takes dance, Pilates and tai chi classes several nights a week and lifts weights to stay fit, and watches what she eats to stay healthy.
"I wouldn't mind losing weight, but I know if I go on a weight-loss diet I'll just spring right back," Mathews said. "What is really dangerous is yo-yo dieting, not to mention destroying people's self-esteem."
The obsession with weight also risks prompting people to overreact, some say.
"We have yuppie parents putting their kids on diets just because they gain a few pounds," Ikeda said. "We see adolescent girls obsessed with obtaining the so-called ideal body image. We see people smoking, abusing laxatives and taking all sorts of extreme measures."
Another danger is that the emphasis on weight may be misleading thin people about their health.
"If someone is in what is considered the normal range, they think they don't have to exercise and can eat whatever they want," Gaesser said.
Willett and others acknowledge that fitness is important and that overweight people benefit from exercise and eating better even without losing weight. But they argue that a careful analysis of many large studies has shown a clear, independent relationship between excess weight and increased risk for health problems.
"When you look at the data carefully, you find that people who are active and lean have the lowest mortality of all," Willett said.
And many obesity researchers take issue with the contention that most overweight people cannot lose weight.
"People can lose weight. They do lose weight," said Arthur Frank, a weight expert at George Washington University. "I've seen people who are indolent in their health habits and they lose weight and their blood pressure comes down and their cholesterol comes down and they feel wonderful, even without doing any exercise."
Willett is also concerned that turning the focus away from weight will keep people from being vigilant about preventing weight gain in the first place, which is the most effective strategy.
"One of the big problems is by the time people become overweight or obese it's very hard for them to become active. They've developed arthritis or other problems that makes it hard, which is why we have to pay attention to weight early on," Willett said.
Despite the intensity of the debate, Willett, Frank, Blair, Gaesser and others have been trying to find common ground, with each side emphasizing that the two ideas are not necessarily mutually exclusive. The best strategy would be to encourage people to exercise regularly and eat well. Some will lose weight, some won't, but all will benefit from getting as much exercise as possible and becoming more physically fit and possibly trimming down in the process.
"This is something that really shouldn't be a debate of one versus the other," Willett said. "It's clear that both fitness and fatness are important. It's definitely good to be as fit as possible no matter what your body weight. But it's also clear that it is optimum to be both lean and fit. It shouldn't be a question of one or the other."