How can you help an anorexic person?

Well, other than shoving food down their mouths and then taping it shut so they can't vomit it back up... Ha... I would try talking to them about it. Maybe they don't realize that it is a problem. But, obviously, if you notice it, it is a problem. Maybe if you are kind and supportive they will be able to resolve their issues. But, if not... Then I would tell someone who could help them. Whether it would be a parent, doctor, teacher, etc. Someone of authority. Someone they might listen to better, or be forced to listen to. Hopefully one of these approaches would work.