Carrying a few extra pounds may not be as bad for your life expectancy as was previously thought, United States researchers suggested on Wednesday.
Overweight people have a lower risk of early death than those whose weight is regarded as normal, according to a study of weight and mortality in the US in 2000.
The figures show that underweight is also associated with excess deaths, although not as strongly as high obesity.
Although the death rate does rise quickly in the very obese, the finding has brought an immediate accusation that the serious health consequences of expanding waistlines in developed countries have been overstated.
The study by researchers at the Centres for Disease Control and the National Cancer Institute, published in the Journal of the American Medical Association, says that previous figures for excess deaths due to overweight were based on inadequate data and inadequate adjustment for other factors.
The new figures indicate that while obesity caused nearly 112 000 more deaths than might be expected, 87 000 fewer people in the overweight category died.
That might suggest that, among the obese and overweight in total, there were just 25 000 extra deaths.
Life expectancy in the US increased from 73,7 to 77 in the 20 years up to 2000, although 65% of people over 20 are overweight or obese.
The association between obesity and mortality may have decreased because of improvements in public health or medical care for obesity-related conditions, the authors say.
But, they add: ”Such speculation should be tempered by the awareness that these differences between surveys may simply represent chance variation and that small variations in relative risk translate into large differences in the numbers of deaths”.
Barry Glassner, a sociology professor at the University of Southern California, said: ”The take-home message from this study, it seems to me, is unambiguous.
”What is officially deemed overweight these days is actually the optimal weight.” – Guardian Unlimited Â