Transcription
There are 35 main reasons we know without a doubt that humans are meant to eat meat.
Reason one, isotopic signatures. Every ancient human fossil ever found has an extremely high marker called nitrogen 15. How this works is nitrogen 15 levels increase the higher you move up the food chain. Plants have the lowest levels. Herbivores that eat these plants have more. Omnivores that eat plants and these herbivores have even more. And top predators have the highest. Humans actually have the highest N15 ratings ever recorded. Higher than lions, wolves, tigers, you name it. Our fossil records show that for nearly all of human existence, we ate at least 80% meat.
Reason two, cave art. When we look at prehistoric cave art, we get a direct window into what early humans actually cared about and relied on to survive. Many of these are over 30,000 years old. Across the world, the animals shown in cave paintings are overwhelmingly large, energy-dense game animals accompanied by human figures showing hunting techniques. As my friend Dr. Anthony Chaffy has stated, I have never seen a cave painting of a salad.
Reason three, copriite analysis. Coily are fossilized human feces. Human copriites from Paleolithic sites frequently contain bone fragments, bone marrow residue, animal fat, and muscle tissue markers, but in many cases, little to no plant fiber is found.
Reason four, tool wear patterns. Historic stone tools show markings consistent with butchering, scrapping hides, and marrow extraction rather than plant harvesting and processing.
Reason five, marrow extraction evidence. Archaeological sites around the world show animal bones deliberately cracked open, proving early humans went out of their way to extract marrow, a highly energy-dense food.
Reason six, stomach acidity. The human stomach is very acidic. This is a trait seen in all cannivorous species, as meat spoils much faster than plants do. This is because meat is rich in protein, fat, and moisture, which create the perfect environment for bacteria to grow. Once an animal dies, bacteria begin breaking down the tissue almost immediately. Hence why our stomach acidity is very similar to other cannivorous species.
Reason seven, no ability for fiber fermentation. Most plants contain very little energy and are largely fibrous. Animals that evolved eating mainly plants have evolved complex digestive systems that are able to ferment fiber and turn it into short-chain fatty acids. Gorillas can ferment over 80% of the fiber they consume. So each gram of fiber they eat counts as two calories. Humans have a very poor ability to ferment fiber. So fiber counts as zero calories when we consume it.
Reason eight, short digestive track. When a primate species has evolved eating plants, they usually have a very long large intestine and digestive tract as this is what fermentss the plant material. Humans have a relatively short large intestine and our digestive tract resembles carnivores not plant fermeners.
Reason nine, tooth structure. A lot of vegans like to argue that our teeth resemble that of herbivores. This is not true. Herbivores have flat teeth optimized for grinding plant material, not sharp teeth like us. Humans have sharp and scissors and canine teeth. And all of our teeth are shaped for slicing and cutting rather than grinding through tough plant material. Our teeth are not as sharp and long as lions and tigers. But this is because they have evolved teeth for killing prey, tearing flesh, and chewing. Whereas we used our intelligence using weapons and tools for hunting and dismantling prey. So we only needed to evolve teeth for chewing meat. This is why our teeth are still sharp but not optimized for killing and ripping prey apart. Our teeth are however optimized for slicing and chewing meat after it has already been killed and cut using tools.
Reason 10, jaw mechanics. Herbivores have mouths that move in a lateral side to side movement as this is what is optimal for grinding plant material. Species that eat meat have rotating jaws as this is optimal for tearing and chewing flesh. Humans have a rotating jaw.
Reason 11, throwing arm. Humans are the only species capable of throwing objects a large distance. This is a trait that could only evolve through throwing weapons at prey.
Reason 12, endurance physiology. No other species is capable of long-distance running like we are. Horses are generally considered the next best endurance runners, and even they can only sustain long-distance movement for a few hours at a time before overheating or needing extended recovery. Humans can run essentially for as long as required. Just ask my boy David. We use this trait for a hunting strategy called endurance hunting, which as the name suggests is the strategy of running prey to exhaustion through tracking and chasing an animal over long distances until it overheats, collapses, and can no longer escape.
Reason 13, feet structure. Herbivores like cows, deers, and horses have hooves or long rigid feet designed for standing and slow energy efficient movement whilst grazing. They lack arches and rely on multiple toes or hooves to support constant weight while feeding. Whereas humans have a strong arch, a stiff midfoot, and a large heelbone. This structure acts like a spring, storing and releasing energy with every step. Our toes are also short and aligned, which reduces energy loss and makes long-distance walking and running far more efficient.
Reason 14, posture. Most other animals are built horizontally, which is better for short bursts of speed, but far less efficient for sustained movement. Humans, however, are uniquely built to stand and move fully upright. Our spine has a natural scurve. Our pelvis is short and B-shaped, and our head sits directly over our spine. This upright posture allows us to balance effectively while walking or running long distances. An upright posture also frees the arms for carrying tools, weapons, and food. This structure makes sense for a species that evolved to travel long distances, track prey, and hunt rather than graze or forage passively.
Reason 15, predator eyes. Prey animals have eyes on the sides of their heads to give them a wide field of view to spot danger. But like most other cannivorous species, we have forward- facing eyes. This gives us binocular vision, meaning both eyes focus on the same point to create depth perception. This ability is critical for judging distance, tracking moving targets, and coordinating precise movements. all traits associated with predators.
Reason 16, lack of plant detoxibility. Every single plant contains toxic compounds called defense chemicals. These are used by a plant to poison any attacker that tries to eat it. When a species has eaten a plant for a very long time, it develops adaptations to break these toxins down. For example, goats produce an enzyme called tennis, which neutralizes a plant defense compound called tannins. Every single species that primarily eats plants has countless adaptations like this. Humans, however, have zero adaptations specifically for breaking down plant defense compounds.
Reason 17, inflammatory response from plants. Because humans have no adaptations to neutralize plant defense compounds, every single plant, at least to some degree, is toxic to us. Because animals defend themselves through physical capability, their muscle tissue does not contain toxins, which is why meat is the only food on the planet that does not contain toxins.
Reason 18, instinctive food preference. Every single wild animal eats what it is intuitively/instinctively drawn to. Humans are not instinctively drawn to broccoli or spinach. Give a vegetable to any child and they hate it. This is because our taste buds detect those plant defense compounds and warn us in the same way our nose detects when something has gone bad and gives us their unpleasant smell. But if you give a kid beef or bacon, they love it. Bitter taste evolved as a warning signal for plant toxins, making humans cautious around unfamiliar vegetation. Humans have specific genes called test 2r genes which code for bitter taste receptors designed to detect potentially poisonous compounds in plants. These receptors are extremely sensitive because throughout evolution consuming the wrong plant could be fatal. There are around 25 tuar genes in the human body each encoding a bitter taste receptor tuned to detect different classes of potentially problematic plant compounds. These receptors detect no toxins in meat because there aren't any.
Reason 19, nutrient density of meat. Meat is the most nutrient-dense food on the planet. Many plants on paper are very high in many nutrients. But because we have not evolved eating them, we have not developed adaptations to access many of these nutrients. This is why with nutrients like iron, we can only absorb as little as 1 to 2% of it from plant sources. Whereas when consumed from an animal source, we can absorb them very effectively. There are 12 nutrients that we cannot get in sufficient quantities or at all from plant sources. Whereas in meat, you get every single nutrient you need in sufficient quantities.
Reason 20, bile acid production. Bile is a digestive enzyme used almost exclusively to digest fat, not carbohydrates or fiber. Cannivorous and omnivorous species that rely heavily on animal fat, such as wolves and lions produce high concentrations of bile. The more fat an animal consumes, the more bile it needs to emulsify and absorb that fat effectively. In contrast, herbivores that eat low-fat, high-fiber diets produce far less bile because they rely primarily on microbial fermentation, not fat digestion for energy. Humans produce a large amount of bile.
Reason 21, protein digestive capacity. Humans are also highly effective at digesting animal protein. We produce large amounts of proteolytic enzymes such as pepsin in the stomach and trison in the small intestine. Our stomach acid activates these enzymes and denatures protein. This makes meat easy to digest and absorb. Our system of doing this is far more developed than what's seen in herbivores.
Reason 22, lack of vitamin synthesis. Vitamin B12 is required for survival. It's needed for red blood cell formation and DNA synthesis along with countless other processes. It only exists naturally in animal foods. Herbivores, however, can get vitamin B12 in a completely different way. They rely on symbiotic bacteria in their stomachs or hind gut that produce B12 during fermentation. Animals like cows, sheep, and deer then absorb that B12 internally or through reingestion. But humans cannot produce B12 on their own. The same is true for other nutrients like vitamin A. Herbivores can create these, but we cannot. Without meat, we become deficient in these essential nutrients.
Reason 23, brain structure. 20% of the human brain is made from longchain fatty acids called carbon 20 and 22 fatty acids. These are abundant in meat, but they are not found in plants. Humans have a very poor ability at converting shorter carbon 18 and below fatty acids into the carbon 20 and 22 fatty acids that our brain structure requires. This is a key reason as to why vegans have smaller brains than people who eat meat. Who would have guessed?
Reason 24, blood sugar sensitivity. Humans experience rapid blood sugar spikes when we consume carbohydrates. When this occurs, it is very damaging. Excess sugar in your blood results in something called glycation, which is where sugar fuses to the outside of your cells and damages them. However, herbivores have stable blood sugar when eating starches. This sensitivity shows we are not adapted to process large amounts of plant sugars and starches, but instead evolved to run primarily on fat and protein.
Reason 25, ketosis advantage. Humans can function extremely well without consistent food intake by switching into ketosis. In this state, the body runs on fat and ketones instead of glucose, which allows for sustained energy, mental clarity, and endurance, even during long periods without eating. This adaptation is ideal for a hunting lifestyle where food was unpredictable and meals were often spaced far apart. Having unstable energy levels and being hangry would certainly not be ideal for optimal hunting or survival in general.
Reason 26, survival intuition. When humans are lost or starving, our instincts naturally draw us towards animal foods rather than plants. This is because most wild plants are bitter, toxic, or indigestible, while animals provide energy dense, reliable nutrition.
Reason 27, huntergatherer behavior. Modern huntergatherer tribes consistently prioritize animal foods when available. Meat, fat, and organs are always the most valued and nutrient-dense resources, whilst plant foods are used mainly as fallback options during times of scarcity. This pattern is seen across vastly different environments from the Arctic to the tropics. This shows that humans instinctively prioritize animal foods when survival is on the line.
Reason 28, opportunistic cannivory. Across the animal kingdom, even strict herbivores will eat meat when the opportunity arises. Deers, cows, horses, and even rabbits have been regularly observed consuming birds, eggs, insects, or carcasses when available. This happens because animal tissue provides dense, immediately usable nutrition that plants simply cannot match. The fact that so many herbivores will opportunistically eat meat shows a simple biological truth. Animal foods are universally valuable. If an animal has the opportunity, ability, and intelligence to access meat, it almost always does. Humans with our advanced cognition and tool use simply took this to its logical extreme. Hence why our fossil record shows that we were almost entirely cannivorous in our past.
Reason 29, cultural emphasis on meat. Across nearly every civilization in history, meat has always been the most prized and prestigious food. It was reserved for feasts, rituals, warriors, and leaders. While plant foods were associated with scarcity, or survival from ancient Egypt and Rome to indigenous hunter societies, meat symbolized strength, status, and abundance. Even in the Bible, this distinction appears clearly in the story of Cain and Abel. Abel's offering of animal sacrifice is favored, while Cain's offering of crops is rejected regardless as to one's religious beliefs. This reflects how ancient cultures viewed animal foods as more valuable, nutrient-dense, and worthy of offering them plant foods. This universal pattern reflects meat's nutritional value and the effort required to obtain it.
Reason 30, ice age survival. For nearly all of human history up until around 12,000 years ago, much of the Earth was covered by ice or impacted by icy conditions. Edible plant life was scarce or non-existent for most of the year. As it was often covered by ice and only grew seasonally for 1 to two weeks. In these conditions, survival depended almost entirely on hunting animals for meat and fat. We simply could not get enough energy from plants to survive.
Reason 31. Creation of fruits and vegetables. 12,000 years ago, as much of the ice around the earth melted, humans began farming livestock and cultivating crops instead of relying on hunting as this provided a more sustainable food source. Every single fruit and vegetable we eat nowadays has only come as a result of our agricultural practices. They are the result of thousands of years of human selective plant breeding. Wild plants were small, bitter, fibrous, extremely low in energy, and very toxic. Through agriculture, we humans have selectively bred plants to be larger, sweeter, and less toxic. You couldn't even eat a considerable amount of potatoes 500 years ago. Wild potatoes contain dangerous levels of glycols and had to be heavily bred and processed to become safe for human consumption. The only wild plants we ate before this time was some wild berries. And these only grew seasonally for about 2 weeks per year, as well as a small amount of tubers, which are somewhat similar to kuma or carrots. Even to this day, huntergatherer tribes only eat these tubers as survival foods if they have no choice. A lot of people have this idea that humans have always been hunter gatherers who killed animals and ate lots of fruits and vegetables. This is not true. These plants are modern creations.
Reason 32: Effort to reward optimization. Humans naturally seek the highest calorie return for the least amount of effort. Animal foods provide far more energy, fat, and usable nutrition per unit of effort than plants do. Hunting one animal can supply hundreds of thousands of calories, while gathering plants requires constant foraging for relatively little return, especially when you consider just how low in energy plants were before relatively recent human manipulation.
Reason 33, post agricultural brain shrinkage. In reason one, we discussed how all human fossils prior to 12,000 years ago showed we were extremely cannivorous due to our high nitrogen 15 ratings. Well, in the last 12,000 years, these nitrogen 15 ratings found in more recent fossils have gradually declined as we began to eat more crops. As diet shifted away from nutrient-dense animal foods and instead became crops, the average human brain size began to decrease. The human brain is now 11% smaller than it was 12,000 years ago. This is in large part due to the lack of essential nutrients and fatty acids in plants.
Reason 34, fossil health evidence. Human fossils found prior to 12,000 years ago had stronger bones, wider jaws, and far fewer signs of chronic disease. Dental decay, bone lesions, osteoporosis, and joint degeneration are rare in these older fossil remains. Once humans shifted to plant-based diets, archaeological records show a sharp increase in cavities, bone deformities, anemia, and markers of nutritional stress. This pattern shows us that our health declines significantly after agriculture.
Reason 35, post agricultural height decline. Another major difference we see in our pre and post agricultural fossils is a difference in height. Post agriculture fossils are about 3 in shorter than pre-aggriculture. Again, this is due to the insufficient nutrients found in plants.
Those are the 35 reasons we know that humans are meant to eat meat. If you want to understand how modern fruits and vegetables were created and why our biology has still not adapted to them, then you will find this video here interesting. Anyway, as always, great speaking with you. to see you next time.