OTHER WAYS TO WORK OUT IF YOU’RE IN DANGER

FOR years, doctors have used the body mass index (BMI) to calculate if your weight puts you at risk of disease — BMI is calculated by dividing your weight by your height, then dividing the answer by your height again (use the online calculator at safefood.eu).

But with question marks about its reliability — and while scientists are still developing the breakthrough new blood test (see main article), here are some alternatives to BMI, now thought to be more useful.

WAIST measurement: It’s very basic but scientists have found that measuring waist size in overweight patients better identifies those at highest risk from diseases such as diabetes.

Overweight people with a large waist — more than 40in for men, 34.5in for women — have been found to have a similar risk of diabetes as obese people. Find the bottom of your ribs and the top of your hips, then measure half-way between these, usually around the belly button.

WAIST-TO-HIP ratio: This is calculated by dividing your waist size by your hip size (for instance, divide a 35 inch waist by 50 inch hips and you get a ratio of 0.7) — a result of 1 or more in men, or 0.85 or over in women, suggests an apple shape and a raised risk of future health problems.

WAIST-TO-HEIGHT ratio. This is calculated by dividing your waist by your height in inches (for instance, dividing a 35 inch waist by 5ft 5in height results in 0.54 ratio). A result above 0.5 means you need to lose weight.