Are humans herbivores, carnivores or omnivores?

Now this is one carnivore I love.

Now this is one carnivore I love.

Scientific evidence shows that anatomically humans are herbivores. Our stomachs, digestive system,  jaws, teeth, saliva and intestines are the same as that of herbivores and significantly different to carnivores and omnivores. So why are we still eating meat?

There has been an ongoing dispute in our household, and in my mind, about if humans are biologically herbivores, carnivores or omnivores. My mum wants to eat meat for dinner almost every day, whereas I tell her that eating meat is not healthy. I thought I would settle this dispute once and for all by doing a simple search online and finding lots of sites and statistics that explain if we are herbivores or omnivores.

To my surprise I found hardly anything on the topic and no quality websites that explain this question scientifically. I was expecting perhaps medical sites or scientific research on this topic to be everywhere on the internet, but no. There a few blogs and discussion forums on the subject, which mostly disagree with each other, but no ‘serious sites.’

The two most trustworthy and official looking articles I found on the topic are on the PETA site (People for the Ethical Treatment of Animals), who obviously have an agenda, but also are a well known charity so couldn’t afford to be putting lies on their website. And another one on the Vegsource site by Doctor Milton R. Mills on the anatomical differences between carnivores, omnivores, herbivores and why humans are anatomical herbivores.

But why can’t I find more official information on this topic? My assumption is because there is no conclusive research on it and because there are industries that do not want to see this type of research published (meat and dairy industry), or maybe it seems like such an obvious topic to most that no one has bothered to put up any official information online.

But I still want to know the truth, are humans herbivores or omnivores. First, let’s start with hard facts.

Are human bodies designed to eat vegetables, meat or both?

Fact: Human anatomy is the same as the anatomy of herbivores not omnivores or carnivores. 

Stomach – carnivores’ stomachs are 20X more acidic than the stomachs of herbivores, because carnivores don’t chew their meat, they swallow it whole. Human stomachs are same as herbivore stomachs.

Saliva – carnivores have acidic saliva, herbivores and humans have alkaline saliva, which helps pre-digest plant foods.

Jaws, teeth, claws – humans, like other herbivores don’t have the jaws, teeth and claws to kill an animal.

Cholesterol –  is only found in animal products and is detrimental to human and herbivore health but doesn’t affect carnivores.

Intestines – carnivores have shorter intestines 3 – 6X their body length and they are smooth inside so meat can pass through them quickly. Herbivores and humans have long intestines about 10 times their body length, with lots of bumps and pockets for plant food to pass through slowly so as many nutrients as possibly can be taken from them.

Omnivore anatomy

Omnivores, such as bears, are more similar to carnivores in their anatomical structure, than they are to herbivores. This is because in the wild they still need to be able to kill and eat prey with their own hands so to speak, and so in order to have more dominant herbivore features they would have to commit to eating plant only based foods and stop being reliant on feeding off meat. So despite humans being cultural omnivores, they are not anatomical omnivores.

Excess protein makes us ill

All animal products are protein. Humans nowadays eat twice as much protein than they need to. Excess protein leads to osteoporosis, kidney stones and has been linked to cancer.

And now for the soft facts…


Instinctively we are not programmed to go out and kill an animal. When we see a cow in the meadow we don’t have the urge to go and kill it and eat it with our bare hands and tear it apart with our teeth. Whereas if we see an apple tree or a strawberry bush we are drawn to picking the fruits and eating them.

Why do humans eat meat then?

In the past humans started eating meat to survive, when there were no vegetables and fruit available. Humans started eating meat when they discovered fire because they could cook meat, they didn’t eat it raw. Raw meat could lead to food poisoning in humans, because unlike carnivores their stomachs are not strongly acidic to kill bacteria. Historically, meat was expensive and eaten only on special occasions and not daily and sometimes even twice a day like people do now.

Why does meat taste so good?

Surely instinctively we should know what’s good for us and what isn’t? If we weren’t meant to eat meat why does it taste so good and why do we crave it? Perhaps we crave meat for its iron and protein intake as we are not eating the right plant based foods to make up for it. Perhaps it’s like with sugar. We crave the cake, but after we eat it we feel sick.

Why do most doctors recommend we eat meat and dairy for a healthy diet?

My only guess it that this is what they’ve been taught and like the rest of us have been led into believing that eating meat and dairy is necessary for our health. Sometimes it seems that people think that eating meat is more important than eating any vegetables. Often if you tell someone that you don’t eat meat, they will say how you really need meat and how unhealthy you are being, but the same person might not eat any fruit and veg because they just never get around to it and don’t see it as an issue. A simple survey of my fellow shoppers trolley, often confirms that most people buy hardly any fruit and veg compared to the amount of low-quality meat and other junk they eat.

It’s not ethical

Eating standard value meat is not ethical or healthy. Mass factory farming treats animals in an unacceptable way. They live in crammed and filthy conditions, get fed antibiotics and all sorts of other rubbish that you then consume as well when you eat them. They are killed in a way that they often suffer during the process and effectively are subjected to torture. As Linda McCartney once said “If slaughterhouses had glass walls, the whole world would be vegetarian.”

Even if you buy organic and free range meat, there is still the unavoidable ethical issue of killing an animal unnecessarily, just to eat it, when you could have easily done without it.

Conclusion: humans are herbivores

In the end with mixed messages coming from everywhere, it can be hard to know what is the best thing for us. But everyone has to make their own decision, based on the evidence that is available and on their own feelings. For me, the evidence I listed in this post clearly shows that humans are anatomically herbivores. We don’t need to eat meat to be healthy. We just eat it because it tastes good and because that’s what we’ve been taught to do.  But in reality meat is bad for us, bad for animals and bad for the planet.

So my conclusion is: humans are herbivores. What’s yours?

Recommended book: Skinny Bitch, by Rory Freedman includes scientific arguments for eating a plant based diet and includes a horrific portrayal of how badly animals suffer on factory farms (based on the US meat industry).

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6 Responses to Are humans herbivores, carnivores or omnivores?

  1. Alex Brodsky says:

    Great article. Thank you for posting it!
    Your research and conclusions are very similar to mine (health, ethical, anthropological). I have been a vegetarian for a very long time and a vegan here and there. I agree that meat and derived animal products are detrimental to us humans as well as to the planet.
    One of my beliefs is that eating meat and derived products cuts down the life span due to the type of proteins/amino acids as opposed to the vegetable derived food sources.
    A while back I read somewhere (cannot remember where) Biblical references that the antediluvian humans lived up to 1,000 years old because they “did not taste blood”. With the Flood, we adapted to the new style of living and dietary consumption. I am far from being religious however it may be used as a sociological commentary. Not sure how much this story can be trusted though. I did find it interesting.
    That said, the other issue in our society is the over commercialization of food causing more and more food come from the processed sources. While our medicine and quality of life have improved drastically (well, it is a diff conversation as there are costs associated with it), the type of food we consume as an overall society concerns me. The amount of simple carbs in our diets is staggering causing everything from obesity to hypertension, diabetes, immobilization, and finally premature death.
    Anyway, I am going off tangent.
    Thank you for the great article and for making me think on Sunday morning! :)

    • Maia says:

      Hi Alex, thanks for the comment. I’m glad you enjoyed the article. Yes I agree with you. Food wise there is a spectrum from really bad quality food to very high quality. I really think that governments should ban certain types of food that are bad for you and have loads of unnecessary chemicals and substitutes.

  2. Gilles says:

    An interesting piece with lots of valid and interestring points. I can’t help falling back to the top-line view that all animals evolvee and we are omnivores that have evolved to eat anything they can to maximise the cvhances of survival. This is why we are so succesful…and though plants have been the easiest to harvest and so main food source meat has always been a part of our diet and will continue to be so…
    More so vegetarianism is a ‘short lived’ by product of a resource rich western culture that I am sure will onlyy last untilour population reaches a tipping point or new disease/new viral chains wipes out lots of the plants etc…
    A good thoughtful piece though to get the brain juices flowing and debates going :)

    • Maia says:

      Hi Giles, thanks for your comment, I’m glad it got you thinking :-)
      It’s true evolving to eat meat has given us more chance of survival, when there are no plants to eat. But right now we don’t need it anymore.
      I doubt we’ll loose our ability to digest it if we stop eating it now.
      Vegetarianism exists in many non-Western cultures too. India for example is a big example, as many Hindus are vegetarians and have been for a long time.

  3. Ivan says:

    Hi there,

    Just on the vegetarianism in India, a personal observation:

    When I was over there last year, I noticed that Indian people who ate meat (eg Punjabi people) seemed far more healthy and stronger than most of the people who didn’t eat meat. There were exceptions, but generally that’s how it seemed to me. A lot of Indian people I know here are similar.

    Also, a couple of links that may be of interest:!/exjun_

    And have you come across the book, “The Vegetarian Myth” ? Interesting stuff.

    Careful with PETA:

    By the way, I used to want to believe – so badly – that humans are essentially herbivores, and could be healthy being so.

    • Maia says:

      Thanks for the comment and links Ivan, I’ll check them out. It’s hard to know which is right, these are all theories in the end. Meat definitely ensured our survival, but right now I don’t think we necessarily need meat to be healthy. For me it’s also mainly a ethical issue. Sometimes we have to do things that are hard so we can follow our principles.

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