I literally just finished this over the weekend. A fascinating look into the mind of the anorexic/bulemic. Anderson did her homework before writing this book, and it shows in the stark honesty of the characters of Lia and Cassie. "Watching" Lia add calories in her head as she tries to eat as little as possible was absolutely heart breaking. A fast YA read, but one you won't want to put down until you get to the end.
I also learned that there are whole websites dedicated to encouraging anorexia called "pro ana" websites (shout-out to former student Savannah Rohloff who did an excellent speech for my class on this subject). I checked one out--it broke my heart. Anorexia is as much an addiction as alcoholism or drug abuse.