I have twice used Michael Thurmonds Six Week Body makeover. It has worked beautifully. I lost close to 100 pounds on it and 12 pounds the first week! I suspect that people who did not lose weight are those that did not follow it.
My results were so good that people kept asking me "who is your trainer"?
Having said that, I did stray and have gained most of the weight back. For me, it was the cleanest simplest way to eat...very good for keeping your blood sugar stable.
Also, I had a job where I entertained alot, taking clients out to dinner and traveling and once I got the swing of things, this was not hard to adhere to, no matter what my travel situation was or my dinner obligations were. Like anything you have to put some effort and discipline in to get results.