Carnivore Diet: Are Humans Carnivores?

Hey if you enjoy this post, consider Become a Patron!, or join my free Newsletter. For a simply frickin’ awesome range of Carnivore and Keto inspired clothing and products check out my Shop.


The below post is an opinion piece, I am not giving out medical advice or anything like that. I am just trying to think through, why the Carnivore Diet makes me feel so good. I am not trying to hide my beliefs in the shadows, I have being eating a Carnivore Diet since September 2017. So there is your disclaimer.

Facultative Carnivore 

I believe it would be a good idea to consider Humans as Facultative Carnivores. The definition of this is that of an animal that does best on a Carnivorous Diet. The animal can survive but does not thrive on a non-carnivorous diet.


Humans are actually classified as Omnivores. The definition of which is an animal that can live on both plants and meat. Here in lies the problem, it makes no distinction on if they should live on both, or what combination might be best. There is a massive range of animals that are classed a omnivores, and there is a lot of differing digestive systems too. Whereas in the Carnivore group, the digestive systems are very similar. I class a pig as a true Omnivore, as they can truly eat and do well on any combination of meat and plants. One of the things that helps pigs be like this is that they have a functioning Cecum. Humans do not.


I think that by defining Humans as omnivores, complicates nutritional science. This allows for distortions and areas to be exploited by vested interests. We live in a world where it is a given that all fruit and vegetables are good for us, and promote health. If a vegetable is scientifically tested and  it has all these vitamins and minerals we would want and need, but if they are not bio-available and if digesting that vegetable causes inflammation….should that vegetable be eaten?

What I am saying is nutrition is actually about what your digestive system can digest, and what foods would have caused that evolution of the digestive system. This would mean there is a base human diet that would benefit nearly everyone, then the healthier you are the more you can deviate from it and the less robust you are the more you need to adhere to it.

Humans Digestion

To simplify things I will use the word MEAT to mean all animal products like steak, fish & eggs etc. PLANTS will mean everything else like grains, sugar, vegetable seed oils, fruits & vegetables.

So I am just going to work through the digestive system and see what it is designed to digest, and hence what we should eat for optimal health.


Teeth – simply looking at our teeth it would look like our teeth are designed for plants because of the molars and small incisors. Our teeth do not look like a true carnivores teeth. However we evolved by firstly scavenging for meat, then we became persistence hunters, and learned how to hunt with tools. Then of course we learned to cook with fire. Therefore we have never needed claws or large incisors to hunt. We can clearly use our teeth to eat plants and meat. I will caveat this with that populations which primarily eat meat have excellent tooth health, populations that eat starchy carbs have much worse tooth health. So overall, meat for the win. 

Jaws – we have vertical jaws, which means we tear and crush our food. We do not have the jaw size or teeth to process large amounts of plant material considering the energy input we needed. It makes ancestral sense that we ate raw meat, then we learned to cook the meat which made it all the more digestible and nutritious. If plant matter was a significant part of the Homo ancestry, we would have greater evidence for the need for mastication or rumination. Mastication is basically chewing, you would think this is important, but our head shape doesn’t suggest that. Think about it, swallow a chunk of meat whole and some sweetcorn, what plops into the toilet bowl after they have been through your digestive tract…. hint it’s not the meat. Meat for the win. 

Stomach – Our stomach is one of the most acidic stomach ph’s in the animal kingdom and is relatively small. This suggests two things: first we are designed to eat meat because stomach acidic wonderfully breaks down meat and barely touches plants. Secondly it is a defense against bacteria and parasites, which would have been important due to the lack of storage and refrigeration, and we spent a lot of our evolution scavenging for meat that would have been turning bad and had already being partially eaten by a large predator. The general rule is the more acidic the stomach acid the more of a carnivore an animal is. We have the same stomach acid ph as Wolves! It is also important to note that if we were designed to eat a lot of plants, we would likely have some bacteria and/or protozoa in our Stomach like you find in Sheep for example. We do not have either, this means there is no cellulose digestion in the stomach. Cellulose is the rigid cell wall of plants. Meat for the win.

Gallbladder – When we eat food with fat in it, it triggers the gallbladder to release bile. This breaks down fat. Really the only year round source of fat in our past would have been the fat that comes along with Meat. The Gallbladder is present and important in Carnivores, and varies in presence and usage in Omnivores and Herbivores. Humans have a functioning Gallbladders.

Small Intestine – The ratio of small intestine to a large intestine is vital in considering what we should eat. A long small intestine compared to the large intestine, relates to an animal that eats a higher quality less fibrous diet. Meat has excellent nutrient to energy profile, and is around 98% percent digested in the small intestines. Humans have a ratio that shows we have favoured meat to plants. Our ratio of small intestines to body length is 1:4, a dogs is 1:6 and a sheep is 1:25. We are clearly more carnivorous than herbivore. Our evolution meant leaving the trees, where we were probably some sort of frugivore.  As we started eating meat, our brains grew. This led to a problem. The two biggest drains on energy are the Brain and Digestive System. So we traded the length of our digestive system to allow our brains to grow, so we didn’t need a  silly amount of daily calories. So meat caused our brains to grow, which meant we needed more and more meat because we were trading in our ability to eat plants. Meat for the win.

Large Intestine – our large intestine is very short compared to our body length. This is the place where we try to get the last remaining goodness from what was not digested in the Small Intestines.  Basically because we are so poor at digesting plants, this means just absorbing water. Then all the digestive plant matter, just gets pushed through to the Rectum. Most of the diseases of the digestive system like Colitis are found in the large intestine. So this suggests to me we are eating too much food, that needs to pass through the Large Intestine. As meat digests in the small intestine, and therefore is unlikely to cause digestive tract diseases…. meat for the win.

Cecum – to me this is the biggest nail in the coffin for anyone who thinks we should eat a lot of plants. The cecum is filled with bacteria and enzymes, that digest cellulose aka plant cell walls. It is a vital to herbivores and ranges in importance in Omnivores. Humans have a cecum, however it is now just an empty sac, basically just an extension of the large intestines and no further digestion takes part in the cecum. So we had a cecum that is vital for plant digestion, however we evolved to not use it. This is huge because humans probably have the greatest survival instinct ever, so to get rid of something that could have helped us survive shows how little we came value plants in our diet over millions of years.

Conclusion – Humans currently get around 70% of calories from plant matter on the standard western diet. We are currently the sickest and weakest we have ever been. I believe our digestive system runs the most efficiently on meat, which therefore has a knock on effect of better health. If you are struggling with anything, from skin dryness to colitis. Then give Carnivore a try for 30 days, it just might change your life.

Appendix for fun – Needless to say the odd conversation with Vegans crop up on my social media. When I talk to them about ancestral eating, they nearly always send me the same photo, and it is the photo below. So they actually think we are Frugivore’s, well we were I guess. Just it was 5-10 million years ago. Without being disrespectful to the person who created it, it is laughably bad and laughable that someone would use it as evidence.

Let’s have a look at it.


Physiological Food – what they mean here is the desire for food, of which creates the best health. They say ours is Fruit, Veg and nuts. Making no mention of if you only ate these, with no supplementation you would die because of a lack of B12 and K2.

Prehensile Hands – not sure what the point is here. Maybe our hands are designed to pick fruit off trees? and in no way useful for throwing spears at animals!

Walks Upright – not sure how they tie this to anything, maybe its because we resemble a tree trunk?

Mouth Opening is small – erm relatively or actually who knows? Is that a reason not to eat a cow? So maybe Vegans shouldn’t eat watermelons because they are bigger than our small mouths.

Rudimentary Blunt Canines – I have discussed why are teeth are as they are. It would be pretty hard to talk with massive canines too.

Jaw, great lateral and forward mobility – what? no that’s not how a human jaw work. Do we look like a horse when chewing? Nope.

No shear, chew food – oh my days, have they never seen anyone eat a chicken drumstick before? Plus totally ignoring the fact we developed tools to deal with these issues, because we have a large brain!

Big salivary glands – not sure how they link this to plant eating.

Saliva is Alkaline and contains Amylase – this is true a healthy body will have an alkaline ph, but not sure why they think a carnivore’s will be acidic. It isn’t. We do have amylase which breaks down starch, but not enough to be useful mind. It is likely a left over starvation survival mechanism, or we were actually evolving it out altogether.

Alkaline Urine – yes again we do have alkaline urine when healthy, and a slightly acidic state means your body in a potentially diseased state. No animal body works in simple terms, whereas a food item changes your bodies acidity. That would be madness. It is a marker for health though, that is true. My urine is alkaline and I only eat meat.

No uricase – they are suggesting here that this imply’s we should not eat meat, because we would be susceptible to build up of Uric acid… which leads to things like Gout. However Uric Acid is only a problem in the bloodstream, and in humans our Kidneys deal with Uric Acid very effectively. In fact nowadays it is know Gout is not caused by Uric Acid from excess meat consumption, but is from excess sugar consumption aka plants.

Weak stomach acid – now it is getting silly haha. Humans have one of the strongest Stomach Acids in the animal Kingdom!!!

Requires Fiber to stimulate Peristalsis – what they mean by that is the wave like movement of the colon muscles to push food down the intestines. This is true if your large intestine is filled with indigestible plant matter (fiber), you do need more indigestible plant matter to push it out. However when you only eat meat and no fiber, your digestive system works much better in my opinion. Fiber is just an inflammatory irritant, that cereal companies have convinced you is a health food.

Metabolize a small amount of Cholesterol & Vitamin A – not sure what they mean here, are they saying cholesterol is not important or that eating foods high in cholesterol like meat is pointless because it is not metabolized. What I do know is cholesterol is in every cell in your body, and if you don’t eat food that promote it then it will make it itself at a great cost.

Sweat glands in whole body – yes that is true and it made us the best persistent hunters on the planet.

Intestines 9 times the length of the body – nope not true, and even if it was that is still closer to a standard carnivore than a standard herbivore. Vegans often talk about the intestines as a whole, because it makes it seem longer than it is. Our Small Intestine to Large Intestine ratio, means we are better at digesting meat to plants. They ignore that.

Colon is acidic – not sure where they got this, as fair as I am aware the colon is very close to the bodies natural ph and is slightly alkaline if anything. Happy to be proved wrong though.

Does not metabolize cellulose – this is true, very true. This actually proves that humans are no longer furgivores, have likely never been herbivores and are pretty poor omnivores. Cellulose is the rigid cell wall of all plant cells. It is how they can form structures, all the alleged goodness is contained within the cell. So if we cannot digest cellulose, then to me it sees unlikely we considered plants an important part of our evolutionary diet.

Complete Digestion 12-18hrs – not sure where they got this. Biology books will say 6-8 hours.

So the graphic is poor in my opinion, it is clearly wrote by someone trying to suggest that we are frugivores and should not eat meat. The people you have tried to use this as evidence against me, have obviously passed it on believing it to be true or hoping it is true and likely haven’t actually fact checked. You should always look into things and not just presume it is true. This means you should also not believe what I said. I am eating a Carnivore Diet. I am clearly biased the other way. So you need to do your own research, and find out what works for you.

Carnivore Sucess Stories

Charlene Anderson

“As SOON as I switched to animal fat as my fat source instead of “healthy” oils, I ovulated and had a period two weeks later. I couldn’t believe it!!! Why in the WORLD didn’t someone tell me years ago about the importance of animal fat?!?😤 I’ve been more regular since then than I ever was as a young teenager. I’ve had two healthy boys (no complications for me; home births too; mid-wife with Charlie and unassisted with George)! ❤😀

We experimented with pork only to find that it activated symptoms. Ground meats, no matter what type also did.

We continued researching and looked at our wins and fails. It led us to Blake Donaldson who suggested a steak and water diet for his patients. That made a lot of sense to Joe and I. We started with pemmican only for some time, introducing steak eventually. Sure enough, as soon as I decided to go all beef, EVERY SINGLE ONE of my symptoms vanished!!! I couldn’t believe it. Whenever I tried to share my success and happiness about this, it was met with more questionable stares, anger, fear, and rolled eyes than you would ever imagine. So, it was our little secret. And that’s how we kept it until we found others with our point of view.”

Andrew Donovan


That’s not hyperbole. I haven’t had loose stool, let alone an infamous shit attack, since becoming a carnivore.

This might sound silly to someone who’s never had IBS but let me tell you, in no uncertain terms, this diet gave me my life back.

There were so many things I found myself avoiding because I was so petrified about how my body would turn against me. And while I am still trying to rewire the patterns I built into my brain that associate geographic unfamiliarity with IBS, I am light years improved from where I was just a month-and-a-half ago.

If you suffer from IBS, all I can say is this: give the carnivore diet a try for a month and see how your body responds.”

Asti Baykal

“ZC helped me recover from adrenal fatigue and several eating disorders. It also cured my chronic constipation which I suffered for several years.

I have had several blood tests done over the last year, and since going ZC my total testosterone went up 50%, free testosterone went up 250% and I got my libido back. My triglycerides are 44mg/dl. And virtually all other blood markers are optimal levels.

Being a health and wellness coach, stumbling upon such a bizarre (against popular belief) and simple way of living really came as a shock. I cannot personally recommend it enough as it has completely changed my life.”

Inspiration: I am no scientist, biologist, nutritionalist or writer even. However I do like putting my ideas down on this blog. So I do take inspiration from more intelligent low carbers than myself, and I love reading, podcasts and social media. So their knowledge will clearly have helped shape whatever I am thinking at the time. Aka the likes of but not limited to (so check them out): Amber O’Hearn, Shawn Baker, Zeroing In On Health, Tim Noakes, etc

Inspiration: I am no doctor, scientist or even a competent writer haha. However I do love learning. So I am always reading and listening to podcasts, then applying what I have learnt and letting it rattle around my brain for a bit before writing posts on it. I take inspiration from the likes of (but not limited to): Amber O’Hearn, Shawn Baker, Zeroing in on Health, Tim Noakes et al.







9 responses to “Carnivore Diet: Are Humans Carnivores?”

  1. chefbrandonallen Avatar

    This is a fantastic article. I generally only read medical journals and studies because of the amount of misinformation on blogs and random “health coach” websites, so the fact that this kept my attention and piqued intrigued throughout, is amazing. I’ve been doing Keto for 2 years, lost 50 pounds, and then gained 20 back the second I increased my carbs and wasn’t 100% strict. I had to go on antibiotics, twice in the past six months, and have not be able to lose the weight I gained. I’m now on day 4 of the carnivore…or should I say the “human” diet, and already feel much better, have lost 4 pounds, and don’t feel inflamed or sluggish as I have for the past few months since my Keto cycling seemed to become ineffective. I’m not against plants as a whole, so I don’t know how I will feel after I end this carnivore journey, but I am definitely leaning towards more of a 90/10 ratio once I hit my goals with carnivore. Who knows, maybe I will be 100%? Thanks for a professional, well thought out, easily digestible article. Cheers, friend!


    1. ketogenicendurance Avatar

      Thank you very much for your kind words. Good luck on your journey.


  2. The Carnivore Diet Diaries – July 2018 – Ketogenic Endurance Avatar

    […] Check out these posts on: what I eat and why. […]


  3. The Carnivore Diet aka Zero Carbs – 12 days of Meat! (Extra Beef) – Ketogenic Endurance Avatar

    […] I have developed my own way of approaching the Carnivore Diet, and it is the Contemporary Carnivore Diet. Humans are obviously omnivores, however only because it is a poor definition. See this post to see why we are Facultative Carnivores. […]


  4. The Ketogenic Diet Experiments: Carnivore Diet (Extra Beef) – Ketogenic Endurance Avatar

    […] This is why I think it works: Are Humans Carnivores? […]


  5. Ketogenic Diet & Carnivore Diet: Butter vs Margarine (Extra Beef) – Ketogenic Endurance Avatar

    […] This is why I eat like this: Contemporary Carnivore Diet, and why I think it works. […]


  6. Justin Zaffarese Avatar

    Im a 45 yr old guy from Australia . Ive had Crohn’s & IBS since i was 21 . Ive been on every drug there is & am currently taking Infliximab , an immune suppressant.
    Ive spent my life eating lots of protein, carbs & minimal fat . For the past 2 weeks ive been on a strict keto diet , starting with a 3 day fast . Ive already noticed an improvement in my bowel and number of stools per day .
    After reading this article i am going to give the Carnivore diet a try . The old food pyramid i remember seeing at the doctor’s office as a boy seems like a pile of misinformation now .
    If i get positive results i will report back .
    I started thinking to myself what would happen to a lion if its diet consisted of bread , pasta , rice , salad & chips whilst reading this . Or if a rabbit ate only meat ? If a car is designed to run on petrol , what happens if you use vinegar or cordial as fuel ?
    The body is a machine & if its been designed to eat meat & organs then no wonder everyone is sick these days .


    1. ketogenicendurance Avatar

      Go for it! Please let me know how it goes. Good luck.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: