Has anyone read Caesar's Commentary on the Gallic Wars? His discussions of the (paleo) Germanic tribes is very interesting. Meat? Check. Raw dairy? Check. Cold baths? Check. Plenty of time outdoors? Check. Great physical size, strength, and vigor? Check!
The nation of the Suevi is by far the largest and the most warlike nation of all the Germans.... They do not live much on corn, but subsist for the most part on milk and flesh, and are much [engaged] in hunting; which circumstance must, by the nature of their food, and by their daily exercise and the freedom of their life (for having from boyhood been accustomed to no employment, or discipline, they do nothing at all contrary to their inclination), both promote their strength and render them men of vast stature of body. And to such a habit have they brought themselves, that even in the coldest parts they wear no clothing whatever except skins, by reason of the scantiness of which, a great portion of their body is bare, and besides they bathe in open rivers.
Their whole life is occupied in hunting and in the pursuits of the military art; from childhood they devote themselves to fatigue and hardships. Those who have remained chaste for the longest time, receive the greatest commendation among their people; they think that by this the growth is promoted, by this the physical powers are increased and the sinews are strengthened.... They do not pay much attention to agriculture, and a large portion of their food consists in milk, cheese, and flesh.
There are many modern studies of the remaining hunter-gatherer tribes, but who knows about other ancient texts that describe pre-agricultural peoples?