What clinical finding supports the diagnosis of an eating disorder in a patient?

A body mass index (BMI) of 17.5 is a significant clinical finding that supports the diagnosis of an eating disorder because it indicates that the individual is underweight. The normal BMI range is considered to be between 18.5 and 24.9, so a BMI below 18.5 is often categorized as underweight. This can be indicative of disorders such as anorexia nervosa, where individuals may engage in restrictive eating behaviors leading to low body weight.

In the context of eating disorders, a very low BMI can be a key criteria in diagnosis, alongside other psychological and behavioral indicators. Factors such as self-esteem, eating patterns, and weight gain can provide additional context but do not directly indicate an eating disorder as strongly as an underweight status reflected in a low BMI. Therefore, a BMI of 17.5 directly correlates with potential health risks associated with eating disorders, making it a critical factor in the clinical evaluation of such conditions.