There is nothing subtle about a 200-pound, fat-flanked steer hindquarter slung on a man's back. The sight brings out the red-blooded Neanderthal in even the Mason-jar-wine and skinny-jeans crowd at Oakland's Eat Real Festival in September. Despite the event's civilized sponsorship partners, like Whole Foods and Prius, the spectators roar and whistle as if a gladiator had entered the Colosseum. The charge is visceral, vaguely sexual. "Kill somebody!" one man yells. Staffers hang up the leg by its heel on a hook. "Bring on the ketchup!" "Give us some scraps!" The crowd sees a naked animal carcass, arguably as provocative...