London - The key to living longer is having a waist measurement no bigger than half your height, according to research.
Scientists have devised a simple formula to predict how many years of life someone will lose to obesity.
And they claim the rule applies regardless of age, gender or ethnicity.
It is worked out by measuring around the waist – technically between the lowest rib and hip bone – making sure you do not breathe in.
As long as this is half your height or less, you should live to the average life expectancy, which is currently about 81.
But for every few centimetres over, you face losing months, even years of life.
For example, an average 30-year-old man who is 1.7m tall should have a waist size no bigger than 88cm. A 30-year-old 1.6m tall woman should have a waist size of 81cm or under.
If the man’s waist size expands to 106cm – or 60 percent of his height – it will knock 1.7 years off his life, according to the formula. Likewise if the woman’s waist grows to 97.5cm, she will lose 1.4 years.
This may not sound much but it quickly adds up if someone is obese.
A 30-year-old man of 1.7m with a 142cm waist can expect to lose 20.2 years from his life expectancy. A woman with a 129.5cm waist will die 10.6 years earlier.
The researchers at Cass Business School at City University, London, came up with the calculation after looking at records of more than 300 000 adults spanning 20 years. Dr Margaret Ashwell says it should be used as a simple health check that anyone can do at home.
She says waist circumference is important because it shows the amount of central fat in the body – which is linked to high cholesterol, diabetes and heart disease.
She also believes the waist-to-height ratio is a far more reliable predictor of ill health and obesity than the Body Mass Index (BMI), which is widely used by doctors.
“People are living in false hope if they rely on their BMI figure. We have to measure the right thing,” she says.
The BMI compares a person’s weight to their height, and puts about 60 percent of Britons in the overweight category. But Dr Ashwell says if the government were to use waist measurement instead, this would go up to 69 percent.
However Dr Rachel Pryke, clinical spokeswoman on nutrition at the Royal College of GPs, says it is unclear whether “worrying people about their weight actually motivates them to make a long-term commitment to lifestyle changes”. – Daily Mail