Yeah, I have those dreams, too. It's a funny thing, because most of the time I have no cravings for the things I eat in my dreams. Like after months of having no sugar or white flour, I'll dream of eating a donut. Then in the dream I always am like "Damn, I messed up. Might as well eat other forbidden things" and I keep eating. Maybe you're right, maybe it is a subconcious way of being allowed to cheat, since my mind knows I'm serious about not having that stuff.

Fata Morgana