Everybody go read 'Call Me Pretty'! It's about a girl named Dominique. She is so desperate to be pretty like her sister and everyone around her, that she's starving herself. Her best friend, the boy who has a crush on her, her parents, teachers, even her sister can't find out what's wrong.
It's an inspiring but heartbreaking story, and I love it. It just happens to be a Harry Potter fanfic as well, but not really, it just uses the same characters and settings, as a guide, so even if you're not a potterhead you should read it!