The body mass index (BMI), is a statistical measure which compares a person's weight and height. Though it does not actually measure the percentage of body fat, it is used to estimate a healthy body weight based on a person's height. Due to its ease of measurement and calculation, it is the most widely used diagnostic tool to identify weight problems within a population, usually whether individuals are underweight, overweight or obese.
Medical research recommends a BMI between 20 and 25 for optimum health. The World Health Organisation classifies a BMI of 25 to 30 as overweight, and over 30 as obese.
