I went to the WW a lot of years ago. It did do the trick for me, especially, as galmateb said, it's not really a diet. You can still eat everything you like, but if you eat something "unhealthy", you have to pay for it by not eating something else.
"I followed you."
"Because you were moving. It's impossible to follow someone who is standing still. If I hadn't moved, I would have lost you. Thus, follow."
from: Edge of Destiny