The hunting and gathering activities of early humans required a high-calorie diet consisting of a variety of macronutrients—protein, carbohydrates, and fat. While hunting big-game animals—like deer, horses and animals in the bovine family—provided a large supply of calories all at once, much of these calories came in the form of protein. However, human and Neanderthal bodies have a limit on the amount of protein intake that the liver can handle.
