I fasted for 1 week and 2 days...I lost 13 lbs. I was taking mutivitamins during this, & drinking lots of water. I also have not gained any of the weight back. If you are prone to eating disorders, or have had one at all, I HIGHLY, would NOT recommend fasting at all! I do recommend doing your homework before you do anything like this. If you fast for too long, you can do major damage to your body, and not realize until it's too late. Different things, work for different people, in different ways. Be careful, do your research, and God Bless.