This might belong in IMHO but I’ll try here first.
The question has been rattling around in my head for a while, and a sentence in this week’s TP column has made me finally ask it. (No link because the column isn’t really part of the question)
A Paleolithic diet (at least our best guess) includes meat, for the protein. In its article on Veganism, Wiki also says,
Well, none of these are readily available to our hunter-gatherer ancestors.
Now, it doesn’t take much meat to satisfy our protein needs, about 120-grams (roughly the size of a deck of cards) but our ancestors weren’t just gatherers for a reason.
Could a purely vegetable/fruit/nuts diet have been sustaining some 40,000 years ago?
No. Protein isn’t the most serious issue. Plant foods do not contain vitamin B12. Meat, fish, and seafood are the main dietary sources. Vitamin B12 deficiency may not be intrinsically fatal, but in Paleolithic times would have caused sufficient problems that those suffering from it would likely not be able to forage well enough to sustain themselves or would die of other causes. Modern vegans must either take supplements, eat fortified food, or take other special steps to obtain B12.
The main problem might simply be a lack of energy from plant foods. Most vegetables are not very energy dense, and also since most plant matter is high in fiber you also need to drink a lot of water with them so you don’t get dehydrated.
The fruits you see today in grocery stores are much bigger and sweeter than the fruits people ate before we started selectively breeding them through agriculture. So paleolithic people ate smaller fruits that had less sugar in them.
Paleolithic people probably burned more calories a day then most modern people do. They had to constantly travel to search for food and sources of water, so that’s a lot of walking. They didn’t even ride animals or had any vehicles to help them either. Without air-conditioning and heating, your body has to burn even more calories just to keep your temperature stable. Then you have to do the physical work of starting and maintaining fires without a lighter.
There are no recent hunter-gatherer societies (the best Paleolithic analogy we have) that didn’t use animals as food; although the proportion of animal vs. plant foods varied widely between regions, seasons, etc., the animal portion had a crucial role as a provider of essential amino and fatty acids, “dense” calories, heme iron, calcium, zinc, vitamin D (in low sunlight environs) and B12 vitamin. The modern vegan diet is based on advanced globalization that brings far and wide foodstuffs like cereal grains, soy, walnuts, vegetable oils and supplements together.
You are right. I was thinking vaguely of vitamin deficiencies when I was writing the post, but it was B[sub]6[/sub] I was thinking of which does have non-meat sources (albeit, grain). I plumb forgot about B[sub]12[/sub] which is either meat or supplements. In fact, the Wiki article you linked to says, “Vegans, and also vegetarians but to a lesser degree, may be at risk for B[sub]12[/sub] deficiency due to inadequate dietary intake of B[sub]12[/sub], if they do not supplement.”
Truly, there were no “gather societies” for reason.
Where do gorillas get B12? For that matter, where do cows? Have humans just lost an ability that other animals have? If so, it must have happened before we started eating animals (including insects).
Note that paleolithic societies made primitive stone tools (by definition) and used them for hunting and butchering. Vegans would have no use for such tools.
If I understand our most-likely ancestral history as posited by biologists, our ancestors were likely omnivores going back to the point of calling them any kind of animal at all. No identifiable ancestor of humanity seems to have been vegetarian or adapted to it as far as we can tell. If you were to try waiting no meat without the benefit of agriculture, you’d probably need to find a lot of wild legumes, and you’d run into some pretty severe issues in bad years - much worse than most hunter-gatherers.
To that end, you’d need to spend more time (and scarce calories) searching for foods and trying to create simple tools to get at them. You’d want a lot of digging tools to try and get at root vegetables and to harvest and carry whatever grains and beans you find. However, you’d be doing it without the big caloric payoff of hunting.
B12 is manufactured mainly by bacteria. Cows and other ruminants get it by absorbing it from their gut bacteria. Ruminants are fore-gut fermenters, so the B12 can be absorbed as the digestive mass passes through the hind gut.
As the article says, humans, gorillas, and rabbits are hind gut fermenters. The B12 is produced after the part of the gut where it can be effectively absorbed. Rabbits, and to a lesser extent gorillas, get around this by eating their own poop.
Primitive vegans could potentially solve their B12 needs by eating their own feces as well. But most people find eating a little meat to be a preferable option.
After, surely? If an omnivore loses the ability to obtain B12 from vegetable matter, it’s fine because it gets it from the meat it eats. If a herbivore loses that ability, it dies.
One of the main points of the Paleo diet is that it’s mimicking the diet of the first people to develop reliable tool technology, so they could begin figuring out how to plant crops and harvest them. This also gave them the tools they needed to build corrals for larger animals, and then weapons to smack them in the head and kill them so they could harvest the meat, rather than just pissing them off.
So the Paleo Diet consists of people eating how we ate after the Neolithic Revolution? Because that sounds like farming and animal husbandry (ranching, to you who don’t make your home with the Grange), which are (AFAIK) definitionally not Paleolithic.
They’re trying to ride the very thin line between the hunter/gatherer stage and the established farming & ranching stage, with a very primitive understanding of what they were doing but just beginning to gain the benefits of tool use in regards to quantity and quality of food available.
Interesting, but the fact they don’t specify diets based on region makes it historically questionable. (And questionable in other ways as well. There’s a miasma of racism which hangs over everything which considers population genetics, but the idea of the “thrifty genome” seems to be relatively uncontroversial and I haven’t seen Paleo-branded diets which take such things into account, even though we now, in principle, can think about genetics separately from race. But it never seems to work that way, does it? It never seems to move away from the old Wissenschaft.)
