Why BMI Should Go Bye Bye

A better measurement of health risk exists, but it is not yet a standard tool

There are 1 billion obese people in the world and another 2.5 billion that are overweight. Individuals fall into these categories based on their body mass index (BMI). It is a simple calculation involving a person’s ratio of weight to height. In medical practice, we use it as a vital sign, similar to blood pressure.

However, there are problems with BMI, as has been pointed out increasingly in recent years by medical professionals and organizations. One is that it cannot distinguish between a person’s lean mass and fat mass. Therefore, a body builder may be considered “obese” despite being an elite athlete. Also, among individuals with the same BMI, fat distribution and body composition vary widely. While their BMIs may be the same, their risks for chronic medical conditions like heart disease and diabetes are different.

People at most risk based on indicators involving body fat are those with the most fat deposition in the abdominal region, and for this reason there is a push towards a new method of measuring obesity called the body roundness index (BRI). Data suggests that it can predict health risks better than BMI.

Why BMI ain’t so fly

Although the calculation for BMI was developed in the 19th century, it did not start being used widely in medicine until the 1970s. But even in 1956, there were already clues that increased…