bese people who exercise have half the death rate of those who are trim but don't exercise, a leading expert said Tuesday.
Previous studies linking obesity and death from heart disease and other major killers have missed the important influence of exercise, said Steven Blair, director of research at the Cooper Institute for Aerobics Research in Dallas.
"There is a misdirected obsession with weight and weight loss," he told a meeting of the Association for the Study of Obesity in London. "The focus is all wrong. It's fitness that is the key."
However, some experts cautioned that reaching an appropriate weight is still advisable for preventing other complications of obesity that are not thought to be related to fitness, such as cancer, arthritis and infertility. The ideal is still trim and fit, they said.
"When you look at the data and the number of subjects he's studied and you recognize that Steve is an excellent scientist, I think nobody would say the data are flawed," said Dr. Susan Jebb, director of the Human Nutrition Unit at Cambridge University in England.
"I think that's good news for people who are overweight because it kind of gives them two options. You don't have to lose weight. You can instead improve your fitness," she said. "However, the reality is that both of those are quite tough challenges. The question is just how many people do manage the level of fitness that he is showing is beneficial?"
Blair said that about 50 percent of the obese people in his studies were fit. It is unclear how that compares with the rate of fitness among obese people in the general population.
The studies involved 25,000 middle-aged men and about 8,000 women who were followed for 10 years. Fitness was measured by a standard stress test -- how long people could walk on a treadmill at increasing intensity before becoming exhausted.
