Body Mass Index (BMI)

BMI measures your weight in relation to your height. To establish your BMI, measure your height in metres and your weight in kilograms, after which divide your weight by your height squared:

W + H² = BMI
For instance, you weigh 63kg (10 stone) and are 1.70m (5ft 7in) tall.

1.70 x 1.70 = 2.89
63 / 2.89 = 21.79

A regular BMI should fall between 18.5 and 24.9. Anything in between 24.9 and 29.9 is regarded as overweight and above that qualifies as obese.

The BMI does not distinguish in between fat and muscle, nor does it take into account exactly where your body fat is distributed. This is essential because it's not just the amount or the composition of excess weight that affects health, but its regional distribution - exactly where the additional fat is stored within the body. It is also not a good measure of progress as you get fitter, since increased muscle mass may really make you heavier, even though you'll be substantially leaner and trimmer, and your clothes will fit much better.

The BMI is really a widely utilized measurement of obesity. Many GPs and medical establishments speak about BMI, so knowing your BMI score is useful.