Why do people say anorexia makes you crazy?

Serious disorder: Anorexia has serious distortions of reality associated, misperceptions of wt, body image and others. Severe electrolyte imbalances and malnutrition can cause delirium and dementia like symptoms.

The brain: Lack of emotion, or dysregulated emotion, occurs frequently when the brain has been starved. If the starvation is of long enough duration, apathy and indifference to one's surroundings sets in. This is also seen in famines and with intentional starvation in times of war. Children are especially vulnerable to this, but adults are affected too. Dysregulated emotions can make us look "crazy".