Pollan argues that an unhealthy obsession with nutrition has overcomplicated and harmed American eating habits. Instead, he recommends that Americans should eat the kind of food that their ancestors would've eaten rather than the so-called imitation food that is widely available in shops, markets, and stores.
Pollan lays much of the blame for such eating habits, and the lack of enjoyment of food they generate, firmly at the door of Puritanism. Puritans had a profound hostility towards just about any kind of pleasure one can imagine. And that inevitably included the pleasures of eating. What Pollan, quoting Laura Shapiro, calls the "naked act of eating" was, to the Puritans, nothing more than a biological necessity. One ate because one had to, not because one wanted to, not because any enjoyment was to be had from the activity of eating.
Puritanism implanted within the American psyche the notion that eating is more than just animal indulgence, as Pollan calls it, and that cooking has a much nobler purpose than the simple gratification of appetite. And that noble purpose was sound nutrition and good sanitation. By thus disdaining the proof the palate, i.e. by ignoring what tastes good, Puritans and other righteous Protestants opened the floodgates for all kinds of damaging innovations in American cooking such as the development of low-fat processed food products.