Quoting Smokey_Taboo:" If you arent nursing, look into juice fasting. I'm thinking about giving it a try I've heard really good ... [snip!] ... really good things about how much energy it gives you and how your can drop alot of weight (if thats what your body needs)"
Fasting is never healthy. Weight that is lost by such a drastic measure, does not stay off. Weight loss needs to be healthy and steady - which usually means it takes time. A "fast fix" like a fast or cleanse, is setting yourself up for failure.
Weightloss, to be successful, needs to come from an over all lifestyle change. Healthy eating, more activity. MAKE time for activity, make it a priority. Eat clean and train hard.