What is the preferred method for diagnosing anorexia?

The preferred method for diagnosing anorexia nervosa is a psychological evaluation. This condition is primarily characterized by an intense fear of gaining weight and a distorted body image, leading to significantly low body weight and nutrition-related complications. Therefore, a thorough psychological assessment is essential to understand the patient's eating behaviors, attitudes towards food and body image, and any co-occurring mental health issues.

While imaging modalities like a CT scan or ultrasound may provide information about physical health or complications resulting from malnutrition, they do not diagnose the underlying psychological aspects of anorexia. Blood tests for electrolyte levels can be critical in assessing the physiological status of an individual with anorexia, especially if there are concerns about metabolic or cardiovascular complications due to malnutrition, but these tests do not establish the diagnosis itself without considering the psychological context.

Thus, a psychological evaluation is central to diagnosing anorexia nervosa and should involve standardized diagnostic criteria, comprehensive patient history, and possibly interviews or questionnaires to assess mental health conditions related to eating disorders.