The stress laid on upward social mobility in the United States has tended to obscure the fact that there can be more than one kind of mobility and more than one direction in which it can go. There can be ethical mobility as well as financial, and it can go down as well as up.
Upscale people are fixated with food simply because they are now able to eat so much of it without getting fat, and the reason they don't get fat is that they maintain a profligate level of calorie expenditure. The very same people whose evenings begin with melted goat cheese . . . get up at dawn to run, break for a midmorning aerobics class, and watch the evening news while racing on a stationary bicycle.