Final answer:
The student might be suffering from anorexia nervosa, an eating disorder characterized by consistently eating very little, obsessive fear of gaining weight, and a distorted body image.
Step-by-step explanation:
The student might be suffering from anorexia nervosa, an eating disorder characterized by consistently eating very little, obsessive fear of gaining weight, and a distorted body image. People with anorexia nervosa often see themselves as fat even when they are very thin.