Inspired by Eric Schlosser's devastating 2001 exposé of the food-service industry, Richard Linklater's muckraking film interweaves the travails of the illegal immigrants, McJob teens, and cover-your-ass marketing gurus who make up the dark underbelly of the American dream. EXTRAS ''Upton Sinclair was sort of hovering above us the whole time,'' Linklater says in his commentary with Schlosser. But Bobby Cannavale, who plays a predatory factory boss, wasn't convinced: ''By the way,'' he says in a making-of, ''I'm still going to eat meat.'' A-

