• Keenan Eriksson

Meat Made Us Human

Since beginning my journey to optimize my health, I’ve found myself trying to imitate ancient man as much as possible. Both data and logic support the idea that we are still incredibly biologically similar to cave men, and we can improve our health by imitating our ancestral lifestyle wherever possible.

Whether it’s low stress work schedules, making a point to regularly expose myself to the cold, or just making sure to maintain connection with my personal group of friends, the ways of tribal man have been paramount in my journey to achieve health.

Possibly the biggest component of this process is a diet that is aligned with man’s evolutionary past. For many people, all this means is forgoing grains and dairy (basically the paleo diet,) both of which were uncommon in human nutrition before the agricultural era.

However over time, I’ve come to believe that human nutrition was far different than even the paleo community promotes. I believe that meat fundamentally made us who we are, and that humans have often occupied the position of Earth’s greatest carnivore for thousands of years.

I and many others have benefited greatly from adopting primarily carnivorous diets, and I intend to continue writing about this topic in future articles. This one, however, is about how eating meat appears to have been crucial in our development as a species, and made us the incredible beings that we are today.

This is how meat made us who we are.

Agriculture Is Not An Excuse

Humans around the world eat many plant-based foods. In fact, for the past 7,000 years most humans have gotten most of their calories from grains. Is it truly possible that we have been essentially eating the opposite of what we are supposed to for so long?

Yes, absolutely. Agriculture is not an excuse. If anything, it is a perfect example of how we could be eating completely opposite from how we are evolved to, and have no idea. Here’s the thing, even if carnivore is not the “ideal” diet, the way we’ve been eating for almost 10,000 years is not ideal either.

Humans have been around for close to 200,000 and our ancestors date back 2 million years. So for at least 1,993,000 years, we have been evolving to eat in an environment that lacked agriculture. To speak plainly, we are not biologically optimized for agriculture-based nutrition.

Now, yes, agriculture is in many ways a good thing. The ability to consume grains allowed us to provide a stable calorie source that ultimately led us to creating vast societies.

However, 7,000 years is not even remotely long enough for a species to adapt to such a radical shift in nutrition, and our health made the sacrifice for these advancements. There is clear evidence that agriculture led to immediate consequences for our health. Human dental problems skyrocketed, and brain size has been on the decline since the advent of this revolution.

My point right now is that we cannot use the way most people eat as evidence against diets that may seem extreme to us.

For many of you, none of this is news. These arguments are the basis of diet trends such as primal, paleo, and even keto to an extent.

People are well aware that grains, the primary food agriculture allowed us to consume, are not good for us. Many people, vegans included, believe much more strongly in a hunter-gatherer model for optimal human nutrition.

Well, I think we were much more hunter, and a whole helluva lot less gatherer. Where Would You Find Broccoli In The Paleolithic?

One of the most immediate ways to comprehend how meat consumption made us different is a simple observation of plant foods in a natural environment.

Have you ever seen broccoli growing on a camping trip? How about squash? I’ve seen berries, and I’m sure you have too, but they are often small, bitter, and very low-calorie, not to mention often poisonous.

The plants we eat now are not like those that would have been available to our ancient ancestors. The most calorically dense foods: fruits and possibly tubors like potatoes, were still all-in-all low in nutritonal value.

Furthermore, the best plant foods are not available year round in many of the areas where many thrived. Europe in winter is fairly devoid of edible plant life even now. How about 20,000 years ago while the Ice Age was still a thing?

I’ll admit, none of this represents proof necessarily that we were carnivores, but I think it does highlight a very important point: It is hard to get nutrients and calories from plant foods. As we’ll see in the next section, animal foods make a lot more sense for a species such as ours, which rapidly developed the most advanced brain in all of the animal kingdom. I don’t believe that potatoes are capable of supporting such a change.

Meat Made Man

kotjarko @ stock.adobe.comIt is widely accepted that humans evolved from primates. Some of the major changes that occurred to make us different are the shift to walking upright, the massive reduction in the size of our intestines compared to apes, and most notably, the unlikely, mysterious, and incredibly rapid growth of our brains.

The ability to consume meat as a primary food source may be the missing link behind these changes. Here’s how.

Changes In The Gut

For one thing, let’s look at the digestive system. Human digestive systems are highly acidic. The Ph balance of our gut sits at right about 1.5 on average. This is in line with carnivores! Most omnivores have a gut Ph between 2 and 4 and herbivores Ph reaches as high as 7. Our digestive tract is also much much shorter than our much more herbivorous primate ancestors. Ever notice how big a gorilla’s belly is? They need that gut to extract what little calories and nutrients they can from the leaves and other plant material they spend all day eating.

While human digestive systems are not quite as simple and short as some carnivores, they are much smaller than that of apes. The only adaptive quality of this shift I can see is that we adapted to consuming meat.

This also could be the first step towards developing our large brain. Brain tissue is predominantly made of fat. It is expensive, and requires a lot of nutrition and energy to maintain.

Developing a digestive system that is smaller and requires less energy itself, as well as allowing us to consume nutrient and calorie dense animal foods, would certainly not hurt the ability to support and develop a large and complex brain.

Hunting Adaptations Then there’s the many ways our body changed. We developed bipedalism: the ability to walk upright; This freed our hands to manipulate the environment and to both create and use tools.

We also developed the Achilles’ tendon and diaphragmatic muscle, which in combination with sweat glands, allow us to run great distances without tire. Though many animals can run faster than us, humans are one of the planets greatest natural distance runners and in long races humans often beat out horses.

Born To Run by Christopher McDougal is a phenomenal documentation of these abilities, and though many of the runners in this book ascribe to vegan diets, the use of running as a hunting tool is directly documented. I have also referenced a couple papers linked to the topic below.

Even today, tribes in Africa are able to hunt large, calorie dense animals simply by chasing them to death. These hunters will simply follow an animal til it overheats and faints or dies. This is a completely tool-free way humans can access larger animal prey than primates and even many carnivores can.

Lastly we have our impressive shoulder joint. You might not know this, but our shoulder is uniquely capable of allowing us to throw things with accuracy and precision. Monkeys lack this capability.

Though persistence hunting (chasing an animal until it collapsed) may have allowed us to hunt before we had tools, our shoulder would allow us to become dominant hunters by throwing spears and other objects.

Very few species could truly attempt to kill a mammoth for dinner, yet there is some statistical evidence that man was so effective that we may have driven the wooly to extinction.

Fat Built Our Brains

Lastly, regarding the rapid growth of our brains and the thing that makes us unique even among other carnivores, we could access fat. Anthropologist Jessica Thompson made a powerful discovery: animal fossils that had been cracked open by stone tools.

A taste for fat may have made us human.

Common theory is that humans used tools to help scrape meat from the bones of their kills, but this evidence suggests we had a unique ability to open bones and access marrow, brain, and other valuable tissues.

Combined with the fact humans are one of few primates to regularly hunt animals larger than us, and we have a powerful model for access to fat to support the rapid evolution of our brains.

Brain tissue as we’ve mentioned earlier is primarily made up of fat. I have heard the theory that access to brain as a food may have contributed to human’s rapid development of our own brains. This isn’t even to mention the ability to fish. Even now, fishing is one of the most powerful ways to access high quality fats such as DHA and EPA (essential for brain function,) while using very little of our own energy.

In the time of ancient man, when the oceans had been neither polluted nor overfished, this would have been a powerful and stable resource for nutrients, calories, and brain supporting fats.

Did We Really Make All These Changes For Vegetables?

None of these adaptations imply to me that humans became better at eating vegetables. Apes are better tree-climbers than we are, and what better place to chew on leaves than the safety of a canopy.

Almost every major change that occurred in the evolution of man is a step backward if our goal was to eat more plants, but a major step forward towards eating animals. Still, we do have a background as apes which are largely, though by no means entirely, herbivorous. Even with all of the anthropology listed above, none of these proves humans ate entirely or even primarily meat.

Thankfully, there is a way we can see that many members of the hominis genus including modern many were top-level carnivores.

It’s In Our Bones

I believe that humans throughout history relied primarily on animal foods, most especially from large ruminant animals like the mammoth.

We achieved this via means only we possessed: the ability to use tools to hunt, eat, and throw as well as digestive adaptations allowing us to consume much more meat than our primate ancestors.

Though it could be argued that all I’ve shown is that humans are omnivores, there is evidence that implies we were often full-blown carnivores.

By measuring the amount of δ15N (pronounced delta-15-nitrogen) in the bones of animals, we can see how much meat they consumed and guess their position on the food chain as carnivores, omnivores, or herbivores. Herbivores typically display δ15N of 3–7%, Carnivores display 6–12% and omnivores are typically in between.

Well buckle up there sally, because Neanderthals and ancient man both score in the highest ranges for δ15N. Neanderthals scored 12% and ancient man scored 13.5%. Yep, we often had higher values than Neanderthals, one of our closest relatives who are thought to have subsisted on entirely animal foods, and both of us outperformed other known carnivores of the time period. If we go even further back to Australopithicus, our most ancient known human ancestor from 3.5 million years ago, a divergence can be seen.

Australopithicus, which predated the homo genus, separated into two genuses: Homo-Habilus, which continued to evolve into what is now modern man, and Paranthropus.

Using mineral analysis of fossilized teeth, Paranthropus followed the traditional primate dietary path of continuing to consume plants, a regression from Australopithicus who consumed a mix of animal and plant foods. Homo-Habilus, on the other hand, consumed much more animal foods.

Modern Hunter-Gatherers & The Role of Plants

Vlad Sokolovsky @

Though this is plenty of evidence that humans have on many occasion relied on primarily animal foods, we do have some adaptations to eating plants.

For one thing, we still have molars. Being that our ancestors were primates, who are omnivores that lean towards being herbivores, it could be advantages to retain these teeth for consuming plants when needed. As we’ve mentioned already, our digestive system is not as well suited to plants, however, and we have to use technological adaptations to consume many such foods. This is reflected in the diets of modern hunter-gatherers.

I did not say tribes I said Hunter-Gatherers. Just because a society is tribal today does not mean they are hunter-gatherers. Many tribal societies in the modern day participate in agriculture, which makes them poor models for comparison if trying to understand our evolutionary roots.

Modern hunter-gatherers consume significantly less carbohydrate than other humans, and though the specific numbers vary greatly, carbohydrate represents only 30% of energy intake in the highest carb groups.

On the other end of the spectrum, groups living in northern latitudes often consume 9% or less of their energy intake from carbohydrate. The Nomadic Mongolians, and the Eskimo are known to subsist on almost entirely animal foods. In short, animal foods are a staple for many of these groups, and even the Hadza, a group often referenced as an example of healthy hunter-gatherers who consume high amounts of grains and carbs, get a large amount of their calories from honey which is technically an animal food.

My final point is that meat seems to be an undeniable part of our evolution as a species. I do believe we are adaptable, but I think that plant foods represent survival food more than our dietary foundation.

Even in observing modern hunter-gatherers who do consume higher amounts of plants, the calorie intake is still far lower than what we consume in agrarian society.

On The Carnivore Diet

So where does this leave us as far as recommendations? Well, to put things simply, I am eating a nearly exclusively carnivore diet. There are nuances and caveats, I don’t just eat steaks, for example.

As far as results? I am honestly feeling as healthy as ever and thriving on this dietary approach. Based on the content of this article, I believe this way of eating has been the norm for much of our history rather than the exception. With that said, I think we are capable of consuming plants to a somewhat significant degree. The more close to the equator your ancestral roots, the more likely it may be that you can tolerate plants.

However I am still not convinced they are needed. Meat helped us develop into the incredible creatures that we are today, right up to the one-of-a-kind brain that makes us human.

It seems unlikely to me that we have changed much biologically since animal foods were our staple, and I believe the digestive and physical adaptations that separate us from apes were fundamentally changes to consume animal foods.

In short, I think that people should be aware of the role that animal foods played in our development, and that we may be best suited to a diet that relies on them. If you feel healthy, great. Plant tolerance seems to vary, but if you feel unhealthy, I strongly recommend looking into the carnivore diet.

There are other pieces of this puzzle, and I will continue to write about this topic for many articles to come. For example, check out this piece about the hidden world of plant toxins:

Your Vegetables Want To Kill You

The surprising truth about plant toxins That said, my personal goal is simply to seek the truth of human biology. I am amazed by what we are, and I am amazed by our past. I think this is a compelling field that offers powerful solutions for addressing the waning health of our species. Even so, I will stay open-minded and keep looking for more evidence.

But I believe that meat made us human, and that it is essential to our health and longevity. I hope you enjoyed reading and I wish you all good fortune on your own health and fitness journeys!

  • Facebook
  • Twitter
  • LinkedIn

©2018 by Keenan Eriksson Fitness. Proudly created with