With South Beach, for the first two weeks you are supposed to stick to (non-starchy) veg and lean proteins. It's supposed to break you from your sugar/starch/processed food habits & addictions. But it's not actually getting you into a particular metabolic state or anything, just sort of shocking you back to what might in some lights be considered sane eating habits.

I really really hate that phase. I can do it, but I get so bloody sick of eggs for breakfast. I'm much happier in Phase 2.