the Value of the BMI Measurement



Body Mass Index (BMI) is a frequently used measurement for assessing weight in adults. BMI uses a mathematical equation based on a person’s height and weight.

BMI is one of the best methods for population assessment of overweight and obesity. It is frequently used because it is a good predictor of an individual’s risk of developing a variety of different diseases and health problems related to excess body weight. A high BMI is a risk factor for heart disease. Most health care professionals will use BMI as a reasonable means of identifying if a person is carrying excess weight. Individuals are usually put into the following categories:

Under 18.5 = Underweight

18.5-24.9 = Normal

25-29.9 = Overweight

Over 30 = Obese

It is important to remember that BMI is a screening tool, not a diagnostic tool. For example, if someone has a high BMI other risk assessments must also be done to determine if excess weight is a health risk. Those other assessments may include a family history, and an assessment of eating and activity habits.

BMI does have some limitations. BMI does not take into consideration the difference between excess fat and muscle. As a result, fit individuals with a high proportion of muscle tissue can be categorized as overweight. However, the percentage of those individuals in the average population tends to be small.

For more information about BMI, visit the following web pages from the National Heart, Lung, and Blood Institute:


Assessing Your Risk


Body Mass Index Table