the most ive lost in the shortest time was 12.8 lbs in around 55 hours. Im a high school wrestler, so I really have to watch my wieght. I do very unhealthy stuff although.I barely eat anything and drink anything, make weight, and then go pig out, and continue that cycle for around 4.5 months. It sucks and I know I shouldnt be doing it this way. I say it is possible for you. But if you do it how id do, once you put some food back in your body, your weight goes up like crazy. Good luck with your weight loss if you decide to do it.