Being a little overweight is good for you, a study suggests, but being very thin increases the risk of death, according to the research.
The findings are the result of an analysis by the US watchdog, the Centre for Disease Control. Considered the most comprehensive ever undertaken, it agrees with several smaller studies in recent months.
All show that those who are a little overweight have a lower risk of death than those of normal weight.
As a result, U.S. government experts have dramatically cut the annual number of deaths they blame on people being overweight – from 365,000 to just 25,814.
It means that, officially, more people – 34,000 – now die each year in the U.S. because they are underweight rather than overweight.
Most of these are aged 70 or older. The experts say the definition of a desirable weight range is probably now too low.
They emphasise, however, that there is a difference between being overweight, and being obese – obesity is still a major killer.
Researcher Dr David Williamson, who is overweight himself, said: ‘If I had a family history – a father who had a heart attack at 52, or a brother with diabetes – I would actively lose weight. As it is, I’m comfortable with my size.’ The experts have changed their views on fat and thin people because the new study used more recent data and better statistical techniques, including factors such as smoking, age, race and alcohol consumption.
Based on the new calculations, excess weight drops from the second leading cause of preventable death – after smoking – to seventh.
Biostatistician Mary Grace Kovar said the classification for normal weight is now probably set too low. In addition, ‘overweight’ people are eating more healthily, exercising more, and controlling their blood pressure and cholesterol better than they used to.
The current method of defining obesity calculates BMI, or body-mass index, a person’s weight-to-height ratio. It has been criticised for labelling superfit athletes obese because muscle weighs more than fat.