BMI stands for body mass index and is calculated using a person’s height and weight, according to the Centers for Disease Control and Prevention. Although BMI is not a direct measurement of body fat, it is a reliable indicator of body fat levels in both men and women.
BMI is a helpful tool in identifying when an individual falls into a weight category that may present a higher risk of health problems. However, BMI is not a diagnostic tool, explains the CDC. To determine whether excess weight is a health risk, doctors need to perform further evaluation. For example, diet, physical activity and family history are all relevant to a person’s overall health regardless of BMI.
In some cases, BMI may not be a reliable indicator of body fat, the CDC states. For instance, an athlete may have more lean muscle mass. While the athlete may have a high BMI and technically be considered overweight, he does not have a high percentage of body fat. However, most people with a high BMI do have excess body fat.
A standard BMI calculator is used to interpret BMI for both men and women over 20 years old. The BMI calculator for children and teens is sex- and age-specific. A BMI of 18.5 to 24.9 is healthy, says the CDC. A number lower or higher than this usually means that the individual’s weight is in an unhealthy range, and consultation with a doctor is appropriate.