I did..I used it for a kickoff to exercise to get those first bit of pounds off. I had a friend and my sister that also did it.
It works, the first two weeks are tough, but after that it gets okay. It isn't a diet, it is an education on food really.
I lost 14 lbs those first two weeks, and with treadmill four days a week after that lost 40 over the course of a year.
Those 14-20 lbs they say in those first two weeks is that shock to the system of your metabolism kicking in. After that it is more like a pound per week and then less as you plateau..
You plateau when you are closer to your ideal weight. I went right down to what they doctor said I should be at which was a bit thin. I put back on about 10 of those pounds and feel great.
Again, it is more just knowing about foods...and how your body processes them, so don't go into it thinking, hey a fun diet that I will do for six months and then I'm out...
But they talk about that too. The book isn't a bad read and is probably on Amazon on something used or even at a thrift store or something pretty cheap.