metabolism

Does your metabolism slow down on master cleanse? I did this last summer for 10 days, and I ended up gaining all my weight back. I didn't eat the greatest after the fast though. I am actually surprised I didn't gain even more the way I was eating. I was just wondering if your metabolism is slowed down a lot and if you lose muscle during the fast? Are there any other things I can do besides eating right and exercising after the fast?