Anorexia nervosa isn’t diagnosed based on BMI. That being said, most people diagnosed are underweight which is about 18.5 or less. Keep in mind that BMI charts are very tricky, some consider more factors than others. A simple BMI only required height, age, and weight. Some take into consideration ethnicity, location, family history, ect. Anorexia nervosa is a multifaceted disorder that can be tied to or caused by totally different mental health problems than just weight.
