Chris and All,
I'm a type 1 diabetic, which I know is completely different from type 2, however the issue with carb consumption is still about the same. I've been following the Zone and its actually been working well for me.
For my carb blocks I choose the carbs that are low GI, or more veggies over other carbs. In fact the only starchy carb I eat is oatmeal in the morning. In my opinion, carb consumption is necessary, its just a matter of choosing the correct carbs.
I'm not a doctor, but I have been diabetic for 18 years. I've only met one endocrinologist who point blank told me that I would know more about how my body handles certain foods then any other doctorate out there. Research and studies are great but each person reacts differently to different treatments. I know the foods that give me a hard time (banannas, pasta, potatoes, corn, to name a few) so I avoid them.
Although I regularly see the endocrin doc, I make my own adjustments to insulin. Most don't understand the WOD or the other types of workouts I do, just as I had one doc tell me that I should limit my carb intake to under 30grams a day. I would melt away if I did that.
Long story short, which I am too late for, run everything by your doc, but don't be afraid to speak up when what they say doesn't make sense. Monitor on your own how the WODs make you feel as well as the different foods you consume, its not just as simple as cutting out the cake, cookies, and sweets.
My blood sugar and A1C tests have never been as good as they have been in the past 2 years, which I attribute to kettlebell training, the WODs, and my nutrition. Don't get me wrong I have bad days, and there is still some confusion as to why I get a high or low reading when I haven't changed a thing, but that's bound to happen.
Please let me know how it works out for you, I'd be interested in hearing.