If Wrangham is right, cooking not only gave early humans the energy

 If Wrangham is right, cooking not only gave early humans the energy 

they needed to build bigger brains but also helped them get more calories from food so that they could gain weight. In the modern context the flip side of his hypothesis 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 exercised an hour a day, that would be good news for our health—and for the planet.

The Kyrgyz of the Pamir Mountains in northern Afghanistan live at a high altitude where no crops grow. Survival depends on the animals that they milk, butcher, and barter.