Weighing in on the value of the body mass index

Your BMI estimates your body fat better than the number on a scale. But a tape measure is an equally important tool.

As your BMI rises above 25, so does your risk for developing high blood pressure, diabetes, and cardiovascular disease.
Image: designer491/iStock

The body mass index (BMI), a measurement derived from the relationship between your weight and your height (see box), is a common way to estimate body fat. It's a simple, fast, and essentially free tool that enables doctors to help identify people who might be at risk for health problems—including cardiovascular disease—that are linked to excess body fat.