“But the real revolution came once human ancestors tasted a tuber baked in a lightning-sparked grass fire and realized the value of cooking, Wrangham asserts. Heat turns hard-to-digest carbohydrates into sweet, easy-to-absorb calories. Using the protein, fat, and carbohydrate makeup of modern fruits, seeds, meats, and tubers, Wrangham’s team calculated the caloric value of diets containing various proportions of these foods, assuming a constant total amount of food dry matter. A diet of 60% cooked tubers, about the proportion used in modern native African diets, and no meat boosts caloric intake by about 43% over that of humans who ate nuts, berries, and raw tubers, says Wrangham. A 60% meat diet offers just a 20% advantage.”