Body mass index (or BMI for short) is a tool that uses your height and weight to indirectly measure body fat. For adults, an ideal range is between 18.5 and 24.9; a person with a BMI over 24.9 is considered overweight, and a person with a BMI under 18.5 is considered underweight.
You can find out your BMI by searching for "BMI Calculator" on eMedTV.com. If your BMI indicates that you are overweight, it may be necessary for you to lose weight in order to reduce risks to your health.
While BMI is a good reference for most, it does have its limits. First, it may underestimate body fat in older individuals who have lost muscle mass. And second, it can overestimate body fat in athletes and those with a very muscular build.