I'm on SBD and have been since early July. I had some left over EAS Carb Control Shakes before starting SBD. I know that these shakes and Zone foods are not recommended by SBD. I use them anyway and have not had any negative results. The only thing I can see is that they may slow you down a bit, but hey, it took me 30 years to put on all this weight, so I'm not in any super rush. Sometimes, when I have a craving, I use the chocolate fudge or french vanilla to flavor my coffee. YUM. I also use the Zone drinks to do the same, although they're a little sweeter. I like the Zone bars every so often as meal replacements. They serve 2 purposes: a meal and dessert all in one. Also, in reading about the Zone, it seems to advocate the same principles as the SBD. In my opinion, having these treats won't undo the whole diet plan, so enjoy!