Fat people 'live longer than those who are skinny'

Being overweight can extend your life, according to a major new study that contradicts years of warnings about the fatal implications of Britain's expanding waistlines.

It sounds too good to be true, but doctors say that carrying a few extra pounds may actually reduce the risk of premature death.

The new study shows that people who are modestly overweight have a 6 per cent lower rate of premature death from all causes than people of ideal, "healthy" weight, while even those who are mildly obese have no increased risk. Overweight is defined as a body mass index above 25 but below 30. For a man of 5ft 9ins that is between 12 stone 4lbs and 14 stone 6lbs, or for a woman of 5 ft 6 ins it is between 11 stone 3 lbs and 13 stone 4 lbs. Ideal, healthy weight is defined as a BMI between 18.5 and 25.

Mild obesity (those with a BMI between 30 and 34.9) brings a 5 per cent lower premature death rate, according to the study. Although this was not significant, it suggests there is no increased risk of premature death attached to that weight range.

To those contemplating a new year diet, the news contradicts the received wisdom that being fat reduces life expectancy. It is the second time that researchers led by Katherine Flegal, a distinguished epidemiologist from the National Centre for Health Statistics at the Centers for Disease Control and Prevention in Maryland, US, have studied the link between obesity and mortality.

In 2007 the same group caused consternation among public health professionals when they published the results of a similar analysis that also showed being fat does not shorten life.

Tam Fry, spokesman for the UK National Obesity Forum, said: "Katherine Flegal is an extremely good researcher and I would respect her. But I am flabbergasted. The sum total of medical expert opinion cannot have got it so wrong. The consequences of people taking this research and deciding let's eat and be merry will be catastrophic."

One possible explanation for the findings is that that fat may protect the heart. Carrying extra pounds may also help individuals withstand periods of illness when they lose appetite.