What does the body mass index (BMI) measure?

Body mass index (BMI) is a measurement that relates an individual's body weight to their height, providing a simple numeric figure that reflects whether a person is underweight, normal weight, overweight, or obese. The formula used to calculate BMI is weight in kilograms divided by the square of height in meters. This measurement is particularly useful as it does not require any specialized equipment and can be easily calculated, making it a practical tool for assessing overall body weight relative to height in a population.

While it is true that BMI can give an indication of potential body fat levels, it does not directly measure body fat percentage, muscle mass, or caloric intake. Body fat percentage provides a more specific measurement of how much fat is present in the body relative to other tissues, while muscle mass focuses specifically on the amount of lean tissue. Caloric intake refers to the number of calories consumed, which doesn't correlate with the height-weight ratio that BMI provides. Thus, the correct understanding of BMI focuses on its role in measuring body weight in relation to height.