One of my meals each day is an Atkins protein meal bar. I don't follow the Atkins plan completely, although I did try it for a few months a couple of years ago. It seemed to work for me, but I didn't stick with it.
Substituting one meal with the Atkins meal bar is helping me try to keep my calories down these days, and it doesn't hurt that the chocolate peanut butter bar is delicious (to me).