BMI: why experts are calling for better ways of assessing health than a body mass index

One PhD thesis found that people who focused on a healthy lifestyle, regardless of their body mass index (BMI), had more nourishing dietary patterns. Photograph: Dreamer Company/Getty Images/iStockphoto

Most of us are no stranger to the body mass index: weight in kilograms divided by height in metres squared.

At a population level, research tells us that having a higher BMI is associated with a greater risk of certain conditions, such as type 2 diabetes and high blood pressure. Rates of obesity, according to the World Health Organisation, have tripled globally since 1975.