The Body Mass Index (BMI) is a measure used to determine your relative body weight. It refers the body mass to the square of your height.
Based on the classification of the World Health Organization (WHO) and other studies, the program determines whether your BMI is assessed as underweight, normal or overweight.
The BMI is a guideline because it does not take into account your individual body compartments (including fat and muscle tissue).
Exact measurement of your body compartments allows you to measure the whole-body composition DXA (see Health Services).