Watch: The strange history of BMI, the body mass index

The body mass index, or BMI, is the formula that’s used most often to diagnose overweight and obesity. But unlike other common diagnoses, there is a certain stigma applied to people with a high body mass index, or BMI, which can affect how they are perceived by peers, providers, and society at large.

Despite the ubiquity of the BMI in medicine, many argue that it is a flawed tool, with a strange history. In recent months, the BMI has become more relevant than ever as the new semaglutide weight loss drugs are poised to change how obesity is understood and treated.

BMI is a simple calculation — a person’s weight in kilograms divided by the square of their height. But how BMI is then translated into a diagnosis is complicated and flawed.

Watch this video to learn more about the history of the BMI — how it became so entrenched in medicine and, surprisingly, how its introduction may have set back decades of work on how obesity contributes to disease.

A STAT series is examining new obesity drugs that are transforming patients’ lives, dividing medical experts, and spurring one of the biggest business battles in years. Read more about The Obesity Revolution.