For decades the most widely used indicator of person’s health has been the BMI or Body Mass Index. If you have a BMI of 18.5 to 25 you are classed as ‘normal’ or ‘healthy’. Anything less is underweight, anything more is overweight, and anything above a BMI score of 30 is classed as obese.
However, this ratio between height and weight (BMI is calculated by weight in kilograms divided by height in metres squared) can only provide a general outline of health and doesn’t take into account certain factors, such as muscle density. So a well-developed person with big muscles could be officially classified as ‘obese’, while actually being perfectly healthy.
Now researchers from Cass Business School at London’s City University have come up with a new way to quickly understand basic health, and they believe it can even predict life longevity, too.
In its simplest form, the best sign that you will live a long, healthy life is if your waist measurement is no bigger than half your height. So, whether you are six foot tall with a 36in waist, or five foot tall with a 30in waist, you can reasonably expect to live to an average life expectancy.
However, as the waistband expands, so life expectancy reduces. In the case of 30-year-old people, if waist size is 60 per cent of height, life expectancy drops 1.7 years for men and 1.4 years for women. If waist size is 70 per cent of height, life expectancy drops more than six years for men and almost five years for women. And if waist size is 80 per cent of height, life expectancy drops more than 20 years for men and more than 10 years for women.
As people age, the effects of waist size on reduced life expectancy lessen, and women aren’t as severely affected as men. But, according to the study — which looked at the records of more than 300,000 adults over a period of 20 years — the relationship remains, regardless of ethnicity.
Speaking to the Sunday Times, one of the study’s authors Dr Margaret Ashwell explained that the great benefit of using waist circumference rather than BMI is that it takes into account the amount of central fat in the body. It’s this fat found in the core of the body that is regarded as being most dangerous, being linked to instances of heart disease, high cholesterol and diabetes.
So how do you reduce this fat? We all know the answer — exercise regularly! One good and fun way to do it is to get out on your bike and enjoy some time in the saddle. It’ll make you healthier… and happier!
If you want to see how you shape up, measure around your waist — underneath your lowest rib and above your hipbone. Make sure you’re not breathing in as you do it.
See what your BMI score is here.