Body Mass Index (BMI) is simply a measure of body weight relative to height.

It's of much more use to sedentary folks, than those who are already fit. In fact, I seldom pay much attention to mine.

But if you're like Al, and have allowed life to dictate, it might very well be that you find yourself out-of-shape. If so, it's probably wise to sit up and take note.

Body Mass Index is 'meant' to indicate whether or not you're maintaining a healthy weight, based on your weight-height ratio. It acts as an arbitrary predictor of the risk of disease and death.

As the CDC’s Division of Nutrition, Physical Activity points out, "BMI can be used to screen for weight categories that may lead to health problems but it is not diagnostic of the body fatness or health of an individual."

BMI is intended for use by both men and women, although it does have limitations (as we'll discuss below).