'Forget BMI, just measure your waist and height' say scientists

Your waist should be no more than half the length of your height, according to experts who claim that having too large a trouser size can dramatically shorten your lifespan.

People with the highest waist-to-height ratio, whose waistlines measured 80 per cent of their height, lived 17 years fewer than average.

Keeping your waist circumference to less than half of your height can help prevent the onset of conditions like stroke, heart disease and diabetes and add years to life, researchers said.

For a 6ft man, this would mean having a waistline smaller than 36in, while a 5ft 4in woman should have a waist size no larger than 32in.

Children in particular could be screened as early as five using the waist-to-height ratio to identify those at greatest risk of obesity and serious health conditions later in life, it was claimed.

Researchers from Oxford Brookes University examined data on patients whose BMI and waist to height ratio were measured in the 1980s.

Twenty years later, death rates among the group were much more closely linked to participants' earlier waist-to-height ratio than their BMI, suggesting it is a more useful tool for identifying health risks at an early stage.

By comparing the life expectancies of various groups of people at different waist-to-height ratios, they were able to calculate how many years of life were lost as people's waistlines increased.