"In a society prone to both epidemic and increasingly severe obesity, it may be that those who manage to remain in the 'overweight' class are, in fact, those who are actually doing quite well," said Katz, who was not involved with the study. "This study suggests that if the basis for defining 'overweight' is adverse health effects, we may want to raise the threshold. The definition of 'overweight' should begin where health risks begin."
Katz pointed out that the study looked only at death rates -- not quality of life. And this is an area, he said, that may be affected by being overweight or slightly obese.
"We have recent evidence -- from the Lancet's 'Global Burden of Disease' study -- that we are living longer, but sicker," he said. "It may be that overweight does, indeed, contribute to type 2 diabetes and heart disease, but not to premature death.
"Living is not really the prize; living well is the prize. So we should be careful before jumping to conclusions about these findings."
Dr. Mitchell Roslin, chief of obesity surgery at Lenox Hill Hospital in New York, said it is important to recognize that many people who are overweight may in fact be moving toward obesity and its myriad health effects.
"Your weight is a moving target, and usually in the wrong direction," Roslin, who was also not involved with the study, said. "Unfortunately, many people gain several pounds each year and this becomes a pathway to morbid obesity, which, as the study shows, is very detrimental."
Katz agreed. "'Overweight' does not tend to be a permanent state; it is often a transitional state, leading to obesity," he said. "If you are lean and gain weight, you will become overweight. If you continue to gain weight, you will become obese. If you are slightly overweight, and remain that way, it means you are actually controlling your weight better than most -- and perhaps that's why health risks may not ensue.
"This study is an argument for, not against, weight control -- it just may be an argument for controlling weight in a slightly wider range than we thought."
So this New Year's, as you find yourself standing on the scale, what should your resolution be? Flegal, for one, said that this study should not be a guide to individual action. But Roslin said the study may provide some perspective for those worried about how their weight might be affecting their health.
"The most important message is to eat right and be fit," he said. "Nominal weight loss and stabilization are worthwhile goals. Skinny is not always better."