If you were ever truly anorexic, you would never wish that you could "get it back"... it's a sickness that consumes your every thought. I wish I could give mine to you, because as I sit here at 20 years old, after 5 years of having an eating disorder, I've had to live with heart attacks, panic attacks, stomach ulcers, intestinal disorders, the list goes on and on and on. Try to be happy that you have a body that works efficiently now.
If you really want to lose weight, the best way, in my opinion, is to incorporate an all-raw vegetarian diet into an active lifestyle. Get to the gym, exercise, and eat little meals scattered throughout the day. Good luck!