Body Mass Index is a measure of overweight examining the relationship of height to weight. The BMI is calculated by dividing the weight in pounds by the square of the height in inches and multiplying the result by 705. A desirable Body Mass Index lies between 18.5-24.9. A BMI of 25-29.9 is considered overweight and 30 or more is a predictor of obesity.
It is important to note that using scales or the Body Mass Index as indicators of obesity has a serious limitation. Neither method is useful as a predictor of obesity in muscular populations such as football players, body building, or weight lifters. They are useful, however, in normal, non-athletic groups. Also, the BMI is best suited for describing obesity in populations rather than individuals because of significant measurement variability.