Humans have historically relied on animal foods as the primary source of protein and nutrients.

“the amount of nitrogen in human collagen or the ratio between the nitrogen isotopes and human collagenous tissues was even higher than other known carnivores at the time suggesting that humans and the inner Thals they looked at both Homo sapiens and Neanderthals were eating almost entirely meat based diets”

“you can look at these recent studies that have come out looking at nitrogen levels and the Enders and early Homo sapiens from seventy eighty thousand years ago and they pretty clearly suggest that the nitrogen levels were so high in our collagen that we were eating we were high level trophic carnivores”

“we actually eighty thousand years ago looking at our collagen so teeth and bones had more nitrogen in our bones more of these isotopes isotopic ratios then known carnivores like hyenas so there's very strong evidence and there's a really strong belief that we were actually high-level carnivores”

“what we see is that if we look at the College and the bones of these peoples they have really high levels of different nitrogen isotopes without going into all the minutiae there what that suggests is that as we eat more animals we accumulate more nitrogen”

“we can look and say well hyenas have a certain amount of nitrogen in the bones a specific isotope of nitrogen and the inner thoughts had even more and the Homo sapiens had even more so we were eating bigger animals and we were probably eating almost exclusively animals”

“there's fossil record of 70 80 thousand years ago Neanderthals and Homo sapiens from northern Europe and you look at the collagen structures in those Anam in those humans and Neanderthals and the amount of stable isotopes they specifically used nitrogen was so high in the collagen tissues that it most people argue that they're essentially high-level carnivores”

“and they found that the the first modern humans in Europe and the inner Thals both had this high level of nitrogen and what you do the same yeah they were they were eating the same animals yes”

“invariably the bones showed that we had higher amounts of stable nitrogen in car than known carnivores at the time suggesting that we were eating the majority of our diet from animals 80,000 years ago right hunting so you can look at hyenas and how much how much stable nitrogen isotope they have in their bones and we had more than that so we were eating more and bigger animals than they were”

“these studies which I talked about before which look at stable nitrogen carbon and sulfur isotopes you can see that the levels of those also mimic this is looking in the collagen of Neanderthals and Homo sapiens in northern Europe 50,000 years ago those ratios also mimic those of carnivores meaning we can basically from these isotopes we can see where within the trophic levels we were eating and in all of these cases it's telling the same story whether it's 1.8 million years ago even 250 thousand years ago the story is that we were eating a lot of animals”

“so I think you're referring to the stable nitrogen and carbon isotope studies right yeah yeah yeah I've I've talked about these before as well I don't know if I've talked about it on this podcast but yeah these are some fascinating studies that look at I can tell how far up the trophic level and fossilized human or Neanderthal was based on collagen in their bones looking at the stable d15 nitrogen and the c-13 isotopes and their bones and as you're suggesting I think they also compared them to a arctic fox and hyenas yeah known carnivores at the time we were higher up the trophic chain meaning getting more of our protein from or the majority of our protein from animals rather than planned because I plants accumulate less of these stable isotopes then things higher up the chain so we can see in our collagen how far up the trophic level we are by looking at these and it's it's yeah the title of the paper was like early humans and Neanderthals were high-level carnivores like that right so they said like we were getting all of it from there so right yeah it's quite fascinating”

“looking at d15 nitrogen levels or Delta 15 nitrogen levels in the bones suggesting that those humans and the inner Thals were eating a whole heck of a lot of animals like even more than they were eating larger animals and they they had higher levels of Delta 15 nitrogen than known carnivores like hyenas”

“because of the way that nitrogen and carbon bioaccumulate as you go up the trophic food chain we can see that our protein was coming from animals rather than plants”

“here is the isotopic analysis of neanderthals again these are all also in my book stabilized still patterns reveals diet and mobility of the last neanderthals and first modern humans in europe guess what high level carnivores more delta 15 nitrogen than other known carnivores of the time”

“if you look at the diet of homo sapiens early homo sapiens co-existing with neanderthals 50 000 years ago they were high-level carnivores they had levels of delta 15 nitrogen that were higher than known carnivores meaning they were eating carnivores that our diet was primarily animal based and always has been”

“measure the isotopes of the herbivores the i'm talking about this nitrogen 15 isotope and measure the isotopes in the carnivores in a certain area and measure the isotopes in the collagen of humans from that period and you can you can actually say that this is the trophic level is if you find the centrophilic levels as carnivores have which is normally what you do uh in in those in this period you have a you can place humans as carnivores in the same group”

“there are lots of good studies looking at stable isotopes in the remains of Neanderthals and in the remains of coexistent homo sapiens from 40 to 50 000 years ago this paper is titled exceptionally High Delta 15 nitrogen values and collagen single amino acids confirm neanderthals as high trophic level carnivores”