Ice, I don't know about Atkins, but the Curves program has carb-addicts go low-carb for a few weeks, and then gradually increase metabolism. It goes against popular thinking that if you eat, you gain weight. Curves wants you to increase your metabolism by eating so you end up burning more calories and fat.
In the Phase 1 part, though, you do have to stay low-carb. You can lose weight without sticking to it, but you lose much more when you do, especially in the beginning stages.
I have a few articles about Curves on the Self Development Channel, including their eating program--and how to tell if you should be counting carbs or calories.