I'm sorry to have found this thread so late. I'm going to catch up later, but for now I'll assume the following comments are not too redundant.
Most cannibalistic societies eat humans in a ritual context for "magical" reasons, i.e., incorporating an enemy's powers by eating body parts associated with particular powers (e.g. leg muscle for running speed, eye balls for marksmanship, biceps for strength, etc.--I'm making up the examples). My point is that humans are not part of any known society's cuisine. I've even heard that anthropologists' knowledge of the practice is rarely or never based on first hand observation, mainly on reports by natives of their neighbors' shameful behavior (headhunting, however, is the object of boasting claims).
The Yanomamo of the Amazon (Brazil and Venezuela) are known to eat large spiders. That's not something I would do, even though I know they are nutritious and even if I were starving. Most societies probably have deeply established ontological notions of what is and what is not food. We, however, make the more abstract distinction between food, in the sense of cuisine, and nourishment. As such, we can eat things for survival that we do not classify as cuisine. That's the basis for cannibalism among people for whom it has no ritual function.