BMI is not a direct measure of body fat, so it can be inaccurate for people who have a lot of muscle mass. 

• BMI can also be inaccurate for people who have a lot of body fat.

• BMI doesn't take into account age, sex, or ethnicity. 

• BMI doesn't take into account where your body fat is located on your body (for example, carrying extra weight around your waist is more harmful than carrying extra weight around your hips).