It seems doctors have got it wrong all along.  Being overweight – or even obese – doesn’t necessarily mean you’re unhealthy, and more likely to keel over than your slimmer counterparts.

In fact, a new study has discovered, it’s better to be overweight and healthy than slim and unhealthy, so putting to rest the long-held belief that being at normal weight or underweight is, on its own, the best passport to longterm health.

Researchers have compared weight and cardiovascular risk factors in a group of 5,400 adults, and discovered that around half of overweight people, and one-third of obese people, were ‘metabolically healthy’.  In other words, their levels of the ‘good’ cholesterol, their blood pressure and their blood glucose levels were all in the healthy range. 
By comparison, around 25 per cent of those who were slim or who were not overweight had two risk factors for cardiovascular disease.

The research team from the University of Michigan were surprised by how many overweight and obese people were healthy where it matters.  But they believe that the problem is the BMI (body-mass index) measurement that medicine uses to determine who is overweight or obese.  Obesity, according to the BMI, is a score of 30 or more, while an overweight person registers a score of 25.

In reality, other factors can determine true obesity – such as waist size – and the BMI is a crude measure that will constantly throw up anomalies such as those uncovered by the latest study.

(Source:  Archives of Internal Medicine, 2008; 68: 1617-24).