Paleolithic cuisine was anything but lean and green, according to a study on the diets of our Pleistocene ancestors.
For a good 2 million years, Homo sapiens and their ancestors ditched the salad and dined heavily on meat, putting them at the top of the food chain.
A look through hundreds of previous studies – on everything from modern human anatomy and physiology to measures of the isotopes inside ancient human bones and teeth – suggests we were primarily apex predators until roughly 12,000 years ago.
…
[C]ompared with other primates, our bodies need more energy per unit of body mass. Especially when it comes to our energy-hungry brains. Our social time, such as when it comes to raising children, also limits the amount of time we can spend looking for food.We have higher fat reserves, and can make use of them by rapidly turning fats into ketones when the need arises. Unlike other omnivores, where fat cells are few but large, ours are small and numerous, echoing those of a predator.
Our digestive systems are also suspiciously like that of animals higher up the food chain. Having unusually strong stomach acid is just the thing we might need for breaking down proteins and killing harmful bacteria you’d expect to find on a week-old mammoth chop.