Traditionally, build has been measured by weight and height tables. These tables lacked a single number to identify the health benefits or risks of different body sizes. Fortunately, weight and height measurements can be reduced to a single number that accurately identifies health risks. This number is called the Body Mass Index, or BMI.

The Body Mass Index, BMI, is a calculated number reflecting a person's relative degree of body weight for his or her height. The BMI calculation and results apply to both men and women. The formula is either

• Weight in kilograms/Height in meters²

- or -

• Weight in pounds x 703/Height in inches²

It is simpler to find your BMI by looking up your own height and weight on the table below. The weights listed are the top weight within each BMI column. If your height or weight is not on the table, then you can use the formula above or use one of the many BMI calculators available on the Internet. The National Institutes of Health's calculator can be found at http://nhbisupport.com/bmi/bmicalc.htm

The BMI is a single number that can be used to determine whether a person's build and his or her associated risk of disease are normal or elevated. The National Institutes of Health has established national classifications of varying BMI values. The "normal" or "ideal" category defines the group with the lowest mortality rate. These guidelines are used to develop clinical guidelines for the practicing physician. The experts at the National Institutes of Health established the following categories and associated risks for each weight classification. The classifications below apply to adults over the age of 18. Children between the ages of 3 and 18 must use an age and sex specific BMI chart.

The BMI is an excellent tool to assess risks associated with varying degrees of obesity. The BMI is accurate for all but the most extreme athletes.

The Obesity Epidemic
Everyone finds the issue of weight, overweight, and obesity a sensitive one. However, there is no avoiding the fact that America has a real epidemic of obesity. Obesity is an important part of the cardiovascular risk profile. Overweight and obese people are at an increased risk of heart disease, hypertension, type 2 diabetes, cancer, abnormal lipids, and sleep apnea.

The Future
The very real health issues associated with obesity can only be addressed as the country begins to talk about and do something about the population's weight problem. Wider use of the Body Mass Index as a real measure will help us move toward better health.