Fast food has taken a hit in recent years. “Fast-casual” chains —like Panera, Au Bon Pain, Chipotle, and Baja Fresh—are nibbling at its heels. But Americans still get some ten percent of their calories from fast food. And the menus at McDonald’s, Burger King, and Wendy’s shape the meals served everywhere from school and hospital cafeterias to snack bars and amusement parks.
