What BMI score is indicative of anorexia?

A body mass index (BMI) score that is 18 or less is indicative of anorexia. This threshold is utilized in clinical settings and research to identify individuals who may be experiencing severe energy deficit and are at risk for the negative health consequences associated with very low body weight. Anorexia nervosa is classified as an eating disorder characterized by an intense fear of gaining weight and a distorted body image, leading to significant weight loss.

When a person's BMI falls below 18, it often signifies that their body is not receiving sufficient nutrients and calories to maintain a healthy weight and functioning. This is critical, as individuals with anorexia can face serious health challenges, including cardiovascular complications, electrolyte imbalances, and even life-threatening conditions. Therefore, the designation of a BMI at or below 18 serves as an important clinical indicator for screening and diagnosis of anorexia nervosa.

The other options represent BMI values that are not considered low enough to qualify for a diagnosis of anorexia. For example, a BMI of 20 and above suggests a healthy weight range, while BMIs of 19 or less and 23 or less may still indicate a lower risk but do not fall within the critical range recognized for anorexia nervosa diagnosis.