What does BMI stand for?

Explanation

The Body Mass Index (abbreviated BMI) is a heuristic proxy for human body fat based on an individual's weight and height. It is used to estimate under- and overweight but is not entirely accurate, because it only measures the weight against the square of the height, without counting in e.g. muscles. A BMI under 18.5 equals underweight, whilst a BMI over 25 indicates overweight.