I had a friend who was doing this and I knew it, she never confessed it to me, one day we were having lunch at her place and when we finished she took off to the toilet. When she came out I said to her "I know what you are doing and if you want to kill yourself lets go and I will help you do it properly. This scared her so much into realising that she was going to die from what she was doing and she stopped. Now she is a very healthy person. I am not saying do this to your daughter, but maybe take her somewhere to see people with anorexia and show her what it can do to you if she keeps it up.
