The decaf isn't the problem. The nuts and Atkins bars are. If you aren't losing, figure out what is causing it. The bars contain tons of Maltitol and that can stall you out in a hurry. Eat a real breakfast that will hold you. Make sure you only eat a very small amount of nuts at any time. In the book when Atkins recommends Macadamia nuts, he also says to eat what amounts to a "child's handful".

Good Luck!