The body mass index (BMI) is a statistical measure of the weight of a person
scaled according to height.BMI is calculated as the individual's body weight
divided by the square of their height.BMI is frequently used to assess how much an individual's body weight departs
from what is normal or desirable for a person of his or her height.The excess
weight or deficiency may, in part, be accounted for by body fat although other
factors such as muscularity also affect BMI.