I know a few folks that have had long-term success on WW. None of them were very overweight- they lost 20, 30, 40 lbs and kept it off. That's great for them, but someone that has 30 lbs to lose is (probabbly) not metabolically deranged, so what WW suggests worked fine.

The problem comes when they extrapolate that out to people that have whacked metabolisms.

Look at the people on shows like My 600 Pound Life. They go home and can gain (or lose) a hundred pounds in a few months. Sure they eat tons of bad food, but there is no way I could gain 100 lbs in a short period of time like that. I could gain 20 or 30 for sure, but no where near what I have seen on that show and others like it. Those people have a very different metabolisms.