Hi Sanjuro,
Your last post, while true in certain known cases of malnutrition and starvation, has been generally discounted on the whole. Pre-Industrial man and Paleolithic man in particular are considered to have been much more muscular than us.
Not only did pre-industrial men eat differently; they behaved differently. They did much more physical exercise than we did, and by looking at the bone record paleontologists have determined that Neanderthal and Paleo Man were incredibly muscular.
This article discusses their musculature in greater detail.
Looking at the actual nutritional intake of our ancestors, we see that they ate a diet remarkably rich in Iron, something like 3-5x more Iron than what we're told to have in our diets. Researchers believe that the high Iron diet relates to their increased musculature and their increased levels of dangerous physical activity, as well as the concomitant risk of blood loss.
When Western Doctors started doing anatomical dissections on humans, they primarily dissected young (<40) deceased persons. Not long after the Industrial revolution, the dissection results began to change: medical research dissections gradually shifted from the young men and women with pre-industrial lifestyles to older men and women with post-industrial lifestyles because people were living longer (primarily the result of better hygiene.)
Results of the new, modern dissections became the standard model for human anatomy (remember the book "Gray's anatomy?") and information from the old dissections fell into disuse. Medical historians have recently compared the old dissections to the new, "normal" bodies of modern man and have discovered that, on the whole, pre-industrial man would have been considered to "suffer" from Muscular Hypertrophy! In actuality, however, it's understood that modern man suffers from muscular HYPOtrophy because of the modern sedentary lifestyle that is so popular these days. Moreover, it's not that big of a stretch to consider that Neanderthal and Paleo Man may have been hypertrophic even by pre-agricultural standards.
As such, I believe that a healthy paleolithic human would be much more muscular than us, and would eat accordingly. I also think that if we try to eat like our ancestors, we'd better be ready to behave like them as well... such a high Iron content in such a sedentary lifestyle as the modern lifestyle would quickly cause problems for most people.
Our best bet is to up our exercise and to eat
fresh foods as much as possible. I'll also recommend
Sam Graci's THE FOOD CONNECTION as a good start to healthier eating - you'd be surprised how important meal scheduling is!