Body mass index (BMI) is a measure of body fat based on height and weight that applies to adult men. It’s used to screen for weight categories that may lead to health problems, but it is not diagnostic of the body fatness or health of an individual.
BMI was developed in the 19th century by Adolphe Quetelet, a Belgian mathematician. It is a simple and inexpensive way to assess weight status, and it has been used for decades to track trends in obesity. BMI is calculated by dividing weight in kilograms by the square of height in meters (kg/m2).