Michael Pollan in The Futures of Food writes,

The counterculture seized upon processed food, of all things, as a symbol of everything wrong with industrial civilization. Not only did processed foods contain chemicals, the postwar glamour of which had been extinguished by DDT and Agent Orange, but products like Wonder Bread represented the worst of white-bread America, its very wheat ''bleached to match the bleached-out mentality of white supremacy,'' in the words of an underground journalist writing in The Quicksilver Times.

As an antidote to the ''plastic food'' dispensed by agribusiness, the counterculture promoted natural foods organically grown, and whole grains in particular. Brown food of any kind was deemed morally superior to white -- not only because it was less processed and therefore more authentic, but because by eating it you could express your solidarity with the world's (nonwhite) oppressed. Seriously. What you chose to eat had become a political act, and the lower you ate on the food chain, the better it was for you, for the planet and for the world's hungry.

I never really went that far, but I feel that food that has been processed less is more nutritional and, more importantly, tastes better. So I'm skeptical about the uniquely tailored diets based on one's genes that Bruce Grierson writes about in What Your Genes Want You to Eat. It'll be quite awhile before we're that sure about exactly what people need in their diets.