Hi, I did the master cleanse diet and I would agree that you do lose weight but that's because you aren't eating anything. The problem I had with this deit is what do you do after you complete the diet? It didn't teach you how to lose weight and keep it off. I think this diet would be great for a short term goal of losing weight...like wanting to fit into a particular dress for an upcoming event or something like that. I found that the best "diet" is just completely starting from scratch and changing your entire lifestyle. It's the hardest "diet" by far but it's the only thing I've seen with really dramatic results.