Waist the New Year diet: BMI doesn’t matter

Dec 28, 2006
Robert Matthews

Reckon you need to lose a few pounds after Christmas? Think again

After all the gluttony and the guilt comes the glumness of yet another post-Christmas diet. Around a third of us make New Year resolutions to lose a few pounds, but with 60 per cent of the population labelled overweight or obese, it's clear most will fail.

Now the good news: for most of us it doesn't matter anyway. Scientists are quietly dropping all that stuff about death, disease and body mass index (BMI), as studies reveal we can afford to be porkier than previously thought.

Invented by a Belgian statistician 150 years ago, BMI has long been used to gauge the effects of being overweight. The index is calculated by taking your weight in kilograms and dividing it by the square of your height in metres.

For years health experts regarded BMIs between 20 and 25 as optimal, but anything over 25 as overweight, and over 30 as clinically obese. By this reckoning, at 5ft 10in the average British male should ideally be a trim 11st 3lb, while the typical 5ft 5in female should be 9st 9lb.

But recent research has cast doubt over BMI as a measure of health. In 2006, a study of more than 33,000 American adults revealed that life expectancy is actually highest for men with BMIs of 26 - well into what was regarded as the overweight category, and equivalent to a whopping 24lb extra for the typical man. For women, optimal BMI proved to be around 23.5, almost half a stone heavier than the supposed optimum.

Such findings are leading scientists to abandon BMI in favour of a simpler yet more reliable measure of porkiness: waist measurement. The latest research suggests that men with a waist circumference below 40in - or 35in for women - can probably avoid starting another New Year with yet another dismal diet.

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