If you plan to do a structured fast like The Master Cleanse for de-toxification reasons then I would suggest that you do it.
If not, and its for weightloss I would prbably say no. While fasting can help with weighloss, as someone else has said, it is highly likely that you will gain back the weight and the cravings afterwards are unbelievable. It can become quite a cycle and make you weight really yo-yo. X .