The idea behind fast food is speed and efficiency. When it comes to fast-food chains, McDonald’s is always on the cutting edge of getting people fed quickly—too quickly, some say. In the rush to gobble down food, much of the joy of eating is lost. Fast food is a soulless commodity that neglects the spiritual appreciation of flavor and taste. It can turn what should be a dining place into a biological fueling station. The bad news is that it has just gotten worse. Just when you think the fast-food giant has reached a peak of efficiency, it comes out...