Body mass index (better known as BMI) has long been used to get a quick and easy snapshot of a person’s body fat levels. To calculate someone’s BMI, you divide their weight in kilograms by their height in metres times itself. The resulting number is used to determine a person’s health risk.
Although there are far better ways of getting an accurate measure of a person’s body fat levels – such as using dual-energy x-ray absorptiometry (Dexa) or magnetic resonance imaging (MRI) – these are very resource-intensive. This may explain why BMI has remained the go-to method for measuring health since it first started being used in the latter part of the 20th century.
