Anyone know about the medi weight loss plan?

I have heard a lot about this diet supervised by a doctor can anyone tell me exactcly how it works i know you take some pills to reduce your appetite and also some vitamin b12 shots what exactcly is the shot for and what can you eat on this diet and can you exercise if you are not eating a lot cause i mean your body needs food to do extensive exercise, please be detailed especially about the food you can eat and how much weight you lose every week