Its one of the conundrums for greenies at the moment we cannot make people into vegetarians, if you take a look at our natural diet we are carnivores naturally! due to societies easy access and its greed for immediate satiation we're left with industries that are highly polutant and harmfull to resources.
As I said its a conundrum. I have no idea how to approach it.
The whole idea of "protein complementarity" got started in 1914 when Osborne and Mendel published a paper on rat nutrition. They noticed that baby rats fed a plant food diet did not grow as fast as other rats who ate the same diet plus a lysine supplement. Conclusion: these plant foods needed a lysine supplement.
Unfortunately, the nutritional requirements of rats and humans are quite different, and this was quickly demonstrated by experiments on humans. Studies in which humans have been fed wheat bread alone, or potatoes alone, or corn alone, or rice alone, have all shown that these plant foods contain not only enough protein, but enough of all of the essential amino acids, to support growth and maintenance of healthy adults. Particularly striking were the experiments involving rice: not only was the rice protein more than adequate, it was adequate when only about 2/3 of the calories were provided through the rice. This means that the actual requirement for protein for most individuals is actually less than 8% of calories as stated by the National Research Council; the NRC has padded its figures with a "safety factor" which many individuals do not need.
The hunter-gatherer diet is generally composed of:
This is a small part of the study I've read which kind of mocks the idea that
humans are true herbivors. I will concede though that omnivorous activity is due
part to society developing. One goes in hand with the other.