Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. It’s used to determine whether a person is underweight, normal weight, overweight, or obese.
BMI is an important measure of health because it can help to identify people who are at risk for obesity-related health problems, such as heart disease, stroke, type 2 diabetes, and some types of cancer. It’s also used to track changes in body weight over time.