Some of you seem very knowledgable about nutrition, especially low-carb diets. My question is: how does caffeine interact with these diets?

I've bee on the zone off and on for a while, and in the book, it's mentioned that caffeine will throw off insulin balance and defeat the benefits of the diet. However, I've heard people say that this isn't really true, or that it's only true for some people.

If caffeine does throw off the balance, how much does it take? I drink some things with caffeine, but it's close to the last ingredient. I've been able to lose body fat doing this, but would I be losing it more quickly if I didn't?

Any thoughts on this would be welcome