The focus is that these lean proteins are more filling and they also serve to build up muscle mass. I do know that the more muscle mass you have, the more calories you burn overall (even while just sitting!). I found this article that explains the science behind it: http://www.thefactsaboutfitness.com/research/diet.htm
Also- I've read that all fruits and most veggies will be 0 points value.
Any of our UK friends (or WW leaders) who are doing this....can you confirm or deny this information? I'm extremely curious and anxious to find out the details.