Overweight people live longer indicates study

Fat people have won a reprieve as a study showed those who are overweight live longer than those of normal weight.

Doctors may have to re-think the definition of the ideal weight after researchers found that the risks of piling on the pounds do not become evident until people are extremely obese.

The fashion world's obsession with slenderness will also come under challenge from the finding that being underweight is linked with a higher death rate, too.

The unexpected results, from the latest and most comprehensive study of the impact of obesity, suggest current advice to maintain a normal weight could have to be re-written.

The researchers from the Centers for Disease Control and the National Cancer Institute in the US estimated the excess deaths in the American population linked with obesity.

They found there were 86,000 fewer deaths among the overweight than those of normal weight. Among the obese there were 112,000 excess deaths compared with those of normal weight but most of these - 82,000 - were in the extremely obese with a Body Mass Index of 35 or over. The risks of being underweight were lower with 34,000 excess deaths compared with people of normal weight.

The study, published in the Journal of the American Medical Association, is claimed to be the most rigorous yet with the figures corrected for age, sex, race, smoking and drinking. But its findings conflict with earlier studies published in the Journal that showed a much higher burden from obesity.

Last year, Julie Geberding, director of the CDC, published a paper warning that obesity and being overweight were causing an extra 400,000 deaths a year and that the expanding girth of Americans would soon overtake smoking as the principal cause of premature death.

The authors of the new study say they have taken account of improvements in medical care, such as the wider use of cholesterol lowering drugs, as well as using different statistical methods.

The main health risk in the obese is heart disease but a second study in the Journal, also by researchers from CDC, shows that over the past 40 years cholesterol and blood pressure levels have come down sharply and smoking has decreased - the key factors that cause early death.

Extra weight increases the risk of diabetes and arthritis in the joints, but people have become more aware of the heart risks of obesity and of the need to keep fit and recent evidence suggest walking may have increased.

"The net result of these phenomena may be a population that is, paradoxically, more obese, diabetic, arthritic, disabled and medicated but with lower overall cardiovascular disease risk," the authors say.

The researchers do not offer an explanation of why extra weight may prolong life but previous studies have suggested that the ideal weight increases with age. Older people need extra fat to tide them over when they fall ill and cannot eat normally.

The finding lends support to the theory that it is fitness not fatness that matters.

But the researchers only looked at how long people lived, not at the quality of their lives.

Some doctors have expressed scepticism at the results, warning of the danger of complacency in the face of the epidemic of obesity. But others have welcomed the challenge to the accepted orthodoxy.

Barry Glassner, professor of sociology at the University of Southern California, told the New York Times: "The take home message is unambiguous. What is officially deemed overweight these days is actually the optimal weight."

- INDEPENDENT