How would a guy feel if his girlfriend was anorexic?

It would worry me a lot because anorexia is an unhealthy disorder. It also shows you care more about your appearance than taking care of yourself. In the long run, your overall health is a lot more important than looking a few pounds lighter.

he wouldn't want her more. guys hate sickly skinny women. he would do his best to help you

A guy who cares about his girl would be extremely worried... It would probably cause him a lot of confusion and even possibly fear. He would probably really want to help her or get her the help she needs although he may not even know how. This is a very scary position to put a guy in. It's a lot of pressure he could even feel responsible for her disorder even if it's not his fault. If he is willing a guy would stand by and help if he got mad at her it could be out of frustration cause he didn't understand the sickness.

There is no way he'd want her more. Anorexia is a serious issue and is never a turn on. I'm really hoping you aren't talking about yourself. Eating disorders are NEVER a good decision.

A good boyfriend would be very concerned and attempt to help her. If this is you, please, I urge you to get help.