ummmmmm well my friend does it an unhealthy way and i am trying to get her to stop. so i knwo how much u can lose unhealthy. i am not going to lie to u. u can lose ALOT, but it is terrible for your body. once u done it unhealthy way then it is hard to go back to being healthy again. u stick to it cuss u think u r over wieght even though u arn't and u start gettin really thin and ugly. i wouldn't do it unhealthy. i am thin and u don't see me doing anything unhealthy. u can be thin with out doing it unhealthy.