The most widely used measure of overweight and obesity has been the Body Mass Index (BMI). It is calculated as the weight in kilograms divided by the square of the height in meters (kg/m2). This value is independent of age or sex.

BMI is a guide to the relationship between your weight, height and health. It does not apply to everyone - e.g. children, pregnant women, the elderly and very muscular individuals such as athletes. Consult your doctor of you want to find out more about what might be a healthy weight for you.