Here's another book that I hadn't heard of but that doubtless many people here have already heard of.

Deadly Harvest by Geoff Bond: Deadly Harvest: The Intimate Relationship Between Our Health and Our Food (9780757001420): Geoff Bond: Books

I'm not sure that it says much that hasn't been said by other people—actually, maybe some of what others say comes from here. But the author actually is an anthropologist, so probably has some interesting angles on things.

Here's his site:

Geoff Bond's Evolutionary Lifestyle Anthropology