What is BMI? Body Mass Index (BMI) is a measure that uses your height and weight to work out if your weight is healthy. The BMI calculation divides an adult’s weight in kilograms by their height in metres squared.

Limitations of BMI: While BMI is a useful indicator of healthy weight for a large part of the population, it has its limitations. It does not distinguish between fat and muscle mass, which means very muscular individuals (like athletes) may have a high BMI while having a healthy body composition. It also doesn’t account for factors like age, sex, ethnicity, or body frame.

Why it’s used: Despite its limitations, BMI is widely used as a simple, inexpensive, and non-invasive screening method to identify potential weight-related health problems in adults. It provides a reasonable estimate of body fat for most people.