It's not, if you understand what BMI actually means. BMI is an aggregate metric that has been misapplied to individuals. Due to the averaging effect, it's a p

It's not, if you understand what BMI actually means. BMI is an aggregate metric that has been misapplied to individuals. Due to the averaging effect, it's a pretty decent predictor for groups, but due to variation within groups, it's not going to predict that well for all individuals (except for individuals who are close to the average of the group).