“A friend’s daughter had an eating disorder and ruined her front teeth. The enamel wore off. Her sickness was different, bulimia. She threw up what she ate.”
I’ve heard of this! Bulimia Nervosa is closely related and sometimes girls (and boys but mostly girls) can have both. The constant barfing wears off the enamel on the teeth.
Princess Diana had bulimia nervosa and at one point looked like a candidate for anorexia nervosa. Her sister Sarah did have anorexia, but both of them managed to recover from their eating disorders.