What is body mass index?

People who are attempting to improve their physical fitness may hear a lot about body mass index, or BMI, and wonder just how important a good BMI is to their overall health. That can be hard to determine, especially for people who are unsure just what BMI measures. According to the Centers for Disease Control and Prevention, BMI is a person’s weight in kilograms divided by the square of his or her height in meters. For those unfamiliar with the metric system, that explanation of BMI might not be too helpful. So how is BMI used and what purpose does it serve? BMI might be most useful in a screening capacity, as the CDC notes it is an inexpensive and easily performed method of screening for weight category. For example, by calculating a patient’s BMI, doctors can quickly determine if the patient is underweight, has a normal or healthy weight, or is overweight or obese. Conditions associated with being overweight include heart disease and diabetes, so an easily calculated index determining if a person is overweight (or underweight or obese) can be an effective tool in combatting some potentially dangerous conditions. But physicians won’t base their opinions on patients’ overall health based on BMI alone. In fact, if physicians determine a BMIs is a health risk, they will likely perform further assessments, including skinfold thickness measurements and evaluations of things like eating habits, physical activity and family history. So while BMI might be somewhat confusing, it can still be a valuable tool for people looking to determine just how healthy or unhealthy they are.