Foe. Not because it stalls the weight, though. It's just not as good for you as plain old water. I used to drink diet caffeine free Pepsi all the time. Since I've started drinking water I don't miss it a bit. And I think about all the money I wasted on it! One of the things I've learned with this WOE is that it's not just about eating low carb - it's about eating healthier by eliminating the processed foods.