National Geographic : 2014 Sep
#futureoffood 53 York City. “The human diet goes back at least two million years. We had a lot of cavemen out there.” In other words, there is no one ideal human diet. Aiello and Leonard say the real hallmark of being human isn’t our taste for meat but our ability to adapt to many habitats—and to be able to combine many different foods to create many healthy diets. Unfortunately the modern Western diet does not appear to be one of them. THE LATEST CLUE as to why our modern diet may be making us sick comes from Harvard pri- matologist Richard Wrangham, who argues that the biggest revolution in the human diet came not when we started to eat meat but when we learned to cook. Our human ancestors who be- gan cooking sometime between 1.8 million and 400,000 years ago probably had more children who thrived, Wrangham says. Pounding and heating food “predigests” it, so our guts spend less energy breaking it down, absorb more than if the food were raw, and thus extract more fuel for our brains. “Cooking produces soft, energy- rich foods,” says Wrangham. Today we can’t sur- vive on raw, unprocessed food alone, he says. We have evolved to depend upon cooked food. To test his ideas, Wrangham and his students fed raw and cooked food to rats and mice. When I visited Wrangham’s lab at Harvard, his then graduate student, Rachel Carmody, opened the door of a small refrigerator to show me plastic bags filled with meat and sweet potatoes, some raw and some cooked. Mice raised on cooked foods gained 15 to 40 percent more weight than mice raised only on raw food. If Wrangham is right, cooking not only gave early humans the energy they needed to build bigger brains but also helped them get more cal- ories from food so that they could gain weight. In the modern context the flip side of his hy- pothesis is that we may be victims of our own success. We have gotten so good at processing foods that for the first time in human evolution, many humans are getting more calories than they burn in a day. “Rough breads have given way to Twinkies, apples to apple juice,” he writes. “We need to become more aware of the calorie- raising consequences of a highly processed diet.” It’s this shift to processed foods, taking place all over the world, that’s contributing to a rising epidemic of obesity and related diseases. If most of the world ate more local fruits and vegetables, a little meat, fish, and some whole grains (as in the highly touted Mediterranean diet), and ex- ercised an hour a day, that would be good news for our health—and for the planet. ON MY LAST AFTERNOON visiting the Tsimane in Anachere, one of Deonicio Nate’s daughters, Albania, 13, tells us that her father and half- brother Alberto, 16, are back from hunting and that they’ve got something. We follow her to the cooking hut and smell the animals before we see them—three raccoonlike coatis have been laid across the fire, fur and all. As the fire singes the coatis’ striped pelts, Albania and her sister, Emiliana, 12, scrape off fur until the animals’ flesh is bare. Then they take the carcasses to a stream to clean and prepare them for roasting. Nate’s wives are cleaning two armadillos as well, preparing to cook them in a stew with shredded plantains. Nate sits by the fire, describ- ing a good day’s hunt. First he shot the armadil- los as they napped by a stream. Then his dog spotted a pack of coatis and chased them, killing two as the rest darted up a tree. Alberto fired his shotgun but missed. He fired again and hit a coa- ti. Three coatis and two armadillos were enough, so father and son packed up and headed home. As family members enjoy the feast, I watch their little boy, Alfonso, who had been sick all week. He is dancing around the fire, happily chewing on a cooked piece of coati tail. Nate looks pleased. Tonight in Anachere, far from the diet debates, there is meat, and that is good. j Science prevented the last food crisis. Can it save us again? COMING IN OCTOBER Supercrops help—but biotech alone can’t avert a food crisis. ON THE WEB Join the conversation at natgeofood.com and get daily food news, videos, informed blogs, interactive graphics, bonus photos, and food facts.