Having recently been hospitalized, I took note of what foods I found appealing—and what my body could handle (digestively). Those first few days it was a fruit cup, Italian ice, and mostly Jell-O. Eventually I was attracted to complex carbs and was able to get down an English muffin with orange marmalade. Then came cereal and by the end of my stay, scrambled eggs and bacon. The experience reminded me of a 1926 experiment, in which a Chicago pediatrician allowed children under his care to eat from a selection of healthy choices, any time and as much or as little as they wanted. Some kids were having liver for breakfast. When mono struck the group, they turned to things like beets. As Mark Schatzker points out in his fascinating The Dorito Effect: The Surprising New Truth About Food and Flavor, humans know where to turn for sustenance in nature—the same goes for sheep, goats, and insects, based on experiments. But in a supermarket, our directional systems suffer what one scientist calls “metabolic derangements.” Technology has fooled our brains into thinking some foods are a vital source of nutrition when, in fact, they’re just Doritos. I recently reviewed the book in The Wall Street Journal.