Since you asked, I think it's a terrible idea. I think we need food and calories for optimal health. Why would you even want to attempt something like that?
I think the best way to lose weight and KEEP IT OFF, those being the key words, is to eat a sensible diet with highly nutritional foods - low fat proteins, whole grains and vegetables. Something that is sustainable for life. Not some quick fix that you can't possibly keep up with and when you "go off" of it you quickly regain whatever weight you took off and then some. Think longterm. What can I do forever and ever that will help me take the weight off and then allow it to stay there? You also didn't mention exericse. Exercise is a vital component to any weightloss plan.
There are many different "diet" plan forums here on 3FC. Why not take a look around and see if any of them are of interest to you?