Thursday, March 29, 2007

Are Humans vegetarians or meat-eaters?

I saw this comment at one of the blogs, which prompted me to write this article. According to this commenter:

Humans are originally 100% vegetarian (mainly fruit & leaf eating) being Primates. They are not carnivorous being unable to kill without weapons and eat raw meat, as natural carnivores such as lions, tigers, crocodiles etc do. Only after humans developed a large brain did they invent weapons to kill and fire to cook meat. No natural carnivore need weapons to hunt nor fire to cook meat as they have claws, large canines, speed and strength to kill their own food (without aid of weapons) as well as the digestive system to eat raw meat (without cooking it).

It’s interesting because the author puts forth a hypothesis which is highly debatable. Are humans herbivorous, carnivorous or omnivorous?

First, to say humans are ‘originally 100% vegetarian’ is patently wrong, because there is no valid case to suggest this. Also, to say humans are completely meat eaters is also wrong, because there is no strong case for this either. Most studies suggest we are omnivorous. We tend to eat what is available. Higher order animals such as mammals may or may not be exclusive meat-eaters. Carnivores are those who meat only. Herbivores are those who eat plants only. However, we have different kinds, like mostly fruit eaters (frugivores), and those who eat seeds (gramnivores), and those who eat insects (insectivores), etc. We are not strictly herbivores nor are we strictly carnivores. And interestingly, we tend to be all the above making us omnivores. 

Are we strictly vegetarian? 

We can eat fruits, and only certain leaves, but cannot eat grass (like herbivores do). Our intestine is not designed to eat grass and digest it. Try doing that and you will be dead. Any human, who is left alone in a jungle, desert, snow-capped mountains, or grasslands, will survive through meat-eating, but not through vegetarian food. Look at any herbivore’s teeth and look at human’s teeth. We have remnants of canines which none of the herbivore’s have.

Almost all plant-eating animals have fermenting vats where the food is stored for a while where bacteria works on it. Animals like cows and buffaloes ruminate. Humans have no such mechanism to suggest we are strictly vegetarian.

What are we?

Are we meat-eaters then? Most vegetarians tend to dismiss this because they try to find similarities between a hard-core game hunting carnivore like a lion or a cheetah to show how we don’t have the same capabilities. It’s a wrong comparison. There are many carnivores in nature who do not necessarily hunt the way lions or cheetahs hunt. Killing rats, squirrels, rabbits, hares, and other small animals does not require the same skill as that of a lion hunting a gazelle. A man, even now, can kill a squirrel, dry the meat and digest it.

Most of the settlements (prior to agriculture) are also near water sources- and tend to suggest that man was eating fish, toads, and other water borne animals, and they were also a major source of our protein. All settlements in cold climates relied heavily on eating meat.

Our closest relatives are apes from who we departed six to seven million years ago. That’s when we moved from the tree tops to the grasslands. What was human eating after he moved to the grasslands? Most evolutionists tend to agree that humans were omnivorous, that while being fruit and leaf eaters, humans relied heavily on small game hunting. 

Our food patterns changed heavily once agriculture and domestication started (around 12,000 years ago). That’s when we started to grow grain and also rear animals for consumption (goat, sheep, hen, etc). Fishing was always another source of food. Some populations were primarily based on fish. If we look at the present human population, it is heavily meat eating (and it is not based on our ability to cook, but our ability to grow animals as an industry). Except for few cultures or nations such as India, the world is primarily meat eating.

[In the above discussion, I have not resorted to ethical dilemmas, religion or human morality].

Links: Jared Diamond [Added in 2013], 


  1. Good one and I totally agree....can't really understand how other people can tell me what I have to eat!!....but I think you gotta prepare for more flak on the comments....again!!

    1. Human are vegetarian by nature, because we cannot digest raw meat like meat eater animals.

    2. Also all vegetarian drink water by sucking ,where as meat eater drink water with tongue.

    3. Yes, we can digest raw meat. Just ask people if they eat sushi or steak tartare how they digest it. The answer will probably be 'just fine'.

      And the lapping... That's about the weakest argument you have. Only Carnivorans, an order of mammals, drink by lapping; other carnivores such as snakes and reptiles drink by sucking too.

  2. I know that Chimpanzee, the closest genetic cousin are omnivorous. There is no doubt that human beings were omnivorous. But, how did you manage to say Indians are not meat-eating people? I think most Indians are also non-vegs. I saw the NDTV/CNN-IBN program on this as well.

  3. Having said that, I must add that an omnivore is can not be a natural omnnivore. It has to start from either veg or non-veg and adapt to the other.
    Definition as given as wiki :
    "An omnivore (from Latin: omne all, everything; vorare to devour) is a species of animal that is physiologically adapted for eating and digesting both plant and animal matter."

  4. Diganta:
    I didn't say that 'Indians are NOT meat-eating people'.

    I said, "Except for few cultures or nations such as India, the world is primarily meat eating."

    There is a difference between the two. What I mean is that while there are many vegetarians in India and constitute a good chunk of population, most of the world populations are primarily meat-eaters (barring the latest trend of vegetarianism that is catching on in some of the western countries).

  5. Diganta:
    A species can be a nature omnivore. On the same Wiki (definition of omnivore), you will find this:

    "Humans are an omnivorous species..."

    And they list some natural omnivores on the same site, such as:
    Some fish, Various mammals (Humans, Dogs, Pigs, Bears, etc), Various birds (Chickens, Crows, pigeons, etc).

  6. I did not doubt that human beings are omnivore. But are they adaptive omnivore or not is the question. I searched the internet a lot, but could not conclude. There are papers written both in favour and against it. I think genetics will open the window for this. Till then, no conclusions ...

  7. hi sujai,

    this is the second time, i am corresponding to you. the last time, i stood with you for your comments on reservation and of colas. (it was on mail, i suppose.) I am again appreciating your stand in the omnivorous / herbivorous debate. But this time you have lost those vigor.

    it is not for the first time, I am hearing the very comment you quoted from a blog. But those who are raising it carries a mind full of casteist sentiments. On the contrary, the great grandfathers of the proponents of vegetarianism did ate meat. In Yagas and Yajnas, the meat of Ashwam or horse was to be eaten by the Yajamana. The Brahmins were a meat eating caste. Its after the Buddism came and stood against killing those animals that have use in our agricultural life-style that, the Brahmins suddenly changed their strategy and food habits.

    And when it comes to Kerala, most of the households eat meat, and that too, Beaf. Even upper caste do it. Its only a meagre population who does not even eat fish or boiled eggs. A portion of the Christians (the syrian orthodox) object eating pork. But Ham is a special food among Catholics. The Muslims also does not eat pork. But Buffalo meat is a favorite in most parts of Kerala. Wheal beef is also a delicacy. The most sought after meat here is 'Vediyirachi' or which you brings home hunting. Even while its against law, the dish includes various bird varieties, hare, small deers, wild buffaloes, wild foxes, ant-eaters, big rats referred as 'Panniyeli', a species known here as 'Marappatti', etc. We have even Hindu Gods who are satisfied with meat.

    The stand that, humans are primarily herbivorous is nothing else than mythistory - mixing myths with history.

  8. Hi Snigdha Rebecca Jacob:
    Thanks for writing about eating practices in Indian sub-continent.

    In my article, I did not take into account the recent history of a particular region or nationality. I was looking at it more from an evolutionary perspective (where no cultural aspects governed the eating habits).

  9. so in the "who cares" department of the world is whether or not people were MEANT to eat meat. the fact of the matter is that it has grown continuously out of control. The rapid consumption of meat results in severe environmental issues, along with health issues. Heard of Dr. Atkins? Died of a heart attack. Maybe meat is SUPPOSED to be eaten, but steroids and hormones ARE NOT. And without a lean meat diet, there are health risks to consider. The availability of meat is sickening, and for the most part YOU ARE WHAT YOU EAT. If that's so, THEY ARE WHAT THEY EAT! We can't afford to feed everyone in America alone, what makes you think these animals are eating grade A food? We are consumers, and the NEED for meat in our diets has been replaced by the gluttony of eating meat everyday. Next time you eat a burger, remember that the fossil fuels used to produce JUST A SINGLE BURGER could supply you with 20 miles worth of gasoline.

  10. terms of our history as human beings, we most definitely subsisted primarily on animal foods, as our northern migration severely restricted food variety. However, I am sure that when we began to starve, we ate anything and everything in sight. There have been many discoveries that show the teeth of proto humans as much sharper and more "canine-like" than those of modern humans (possibly due to the advent of fire, or the onset of agriculture). Additionally, numerous well constructed butcher sites have been found, indicating that we ate meat frequently. Honestly, humans invented bows, arrows, spears, and other weapons long before they invented salad spinners and salad tongs. Furthermore, our decreased gut size and increased brain size are directly correlated - our decreased gut size indicates that we ate more energy dense, yet less voluminous foods.

    However, since a lot of relatively advanced nations (i.e. the United States) raise and slaughter animals unhealthily (and inhumanely), it is best to acquire animals that have been fed nature's intended diet (i.e. grass for cows), free from injected hormones and sprayed pesticides. If healthy animal food cannot be obtained at all (because of location, money, etc.), then I highly recommend avoiding it. I still recommend slightly restricting carbohydrates for a healthy diet - grains and starchy vegetables should be avoided; fruits are generally good in moderation. If you absolutely MUST be a vegetarian, make sure to eat mostly nuts and green vegetables.

  11. I know this article is restricted to a debate on physical evolutionary possibilities which seek to explain eating habits. I believe another angle with which to look at is at a 'mental evolutionary' level. Obviously we have moved way up the ladder when compared to primates and other species. From an evolution - of - the - mind - point of view, we have evolved from subsistence to the present day - everything is available and we have the choice to eat or not - mode. It is just a choice we make between eating cooked body part of dead animals / birds Vs. eating cooked grains / vegetables. yes, that might probably border on a moral-values territory. But it is that choice we make which reflects our evolutionary path too.

  12. What we ate centuries ago as cave-dwellers has little bearing on the current food production system. I am a vegetarian, but I believe that we evolved as omnivores, and anyone who says that we are biologically suited only for eating vegetarian food, I'd disagree with.

    But we also did a lot of things in the past - rape, pillage etc. that we don't do now. Or at least, those are punishable by law and I can't justify those acts by claiming biological evolutionary reasons as an excuse.

    We are not mere slaves to our evolutionary past but also have a brain that allows for rational (and rationalizing ;) ) thinking.

    The way meat is produced today in the US (that I'm familiar of) is not healthy for the animals, not healthy for the planet in any sense, and not healthy for humans. Those are indisputable facts. So, if we are to be rational and logical about it, and given the premise that we care about our planet and ourselves, any reasonable person would agree in theory that subsisting on a major meat diet using current methods of production is foolish, and cannot be justified, nor is it sustainable in the long run.

    But I also believe it's a personal choice, and while I would encourage people to find out for themselves how their food is produced and if they would still continue to consume it knowing the costs, I would not impose a vegetarian diet on anyone.

    Two excellent books that I've read and I would recommend to everyone are:
    1. The Omnivore's Dilemma (Michael Pollan)
    2. The Way We Eat - Why Our Food Choices Matter (Peter Singer, Jim Mason)
    Both are mostly pertaining to situations in the US, but can be extrapolated to some extent to any country.


  13. nicely said.
    i'm a vegetarian, and i totally agree. I find it funny when vegetarians argue that we aren't made to eat meat. Any healthy vegetarian knows that when not eating meat one has to take vitamins to stay healthy. I suspect someone attempting to be a carnivore would have to adopt the same habits (with respect to different nutrients).

  14. Any healthy vegetarian knows that when not eating meat one has to take vitamins to stay healthy.

    Not true. A well-balanced vegetarian meal (including dairy) on an average provides all the nutrients that our body needs, unless one has some special needs. If you are a vegan (no dairy, no eggs, no animal products), then you need B12 supplements, or food that is enriched with B12, or nutritional yeast in your food.

  15. Although many modern humans eat a wide variety of plant and animal foods, earning us the honorary title of "omnivore," we are anatomically herbivorous. Biologists have established that animals who share physical characteristics also share a common diet. Comparing the anatomy of carnivores with our own clearly illustrates that we were not designed to eat meat.

    Comparing our anatomies clearly illustrates the fact that the human body is built to run on a vegetarian diet. Humans have absolutely none of the distinguishing anatomical characteristics that either carnivores or even natural omnivores have. Here is a chart from "The Comparative Anatomy of Eating" by Dr. Milton Mills that compares the typical anatomical features of carnivores, omnivores, herbivores, and humans. Notice how closely human physical characteristics match those of herbivores.


    Facial Muscles

    Carnivore Reduced to allow wide mouth gape
    Omnivore Reduced
    Herbivore Well developed √
    Human Well developed √

    Jaw Motion

    Carnivore Shearing; minimal side-to-side motion
    Omnivore Shearing; minimal side-to-side motion
    Herbivore No shear; good side-to-side, front-to-back √
    Human No shear; good side-to-side, front-to-back √

    Teeth (Incisors)

    Carnivore Short and pointed
    Omnivore Short and pointed
    Herbivore Broad, flattened, and spade-shaped √
    Human Broad, flattened, and spade-shaped √

    Teeth (Canines)

    Carnivore Long, sharp, and curved
    Omnivore Long, sharp, and curved
    Herbivore Dull and short or long (for defense) or none √
    Human Short and blunted √

    Teeth (Molars)

    Carnivore Sharp, jagged, and blade-shaped
    Omnivore Sharp blades and/or flattened
    Herbivore Flattened with cusps vs. complex surface √
    Human Flattened with nodular cusps √


    Carnivore None; swallows food whole
    Omnivore Swallows food whole and/or simple crushing
    Herbivore Extensive chewing necessary √
    Human Extensive chewing necessary √


    Carnivore No digestive enzymes
    Omnivore No digestive enzymes
    Herbivore Carbohydrate-digesting enzymes √
    Human Carbohydrate-digesting enzymes √

    Stomach Acidity

    Carnivore Less than or equal to pH of 1 with food in stomach
    Omnivore Less than or equal to pH of 1 with food in stomach
    Herbivore pH of 4 to 5 with food in stomach √
    Human pH of 4 to 5 with food in stomach √

    Length of Small Intestine

    Carnivore 3 to 6 times body length
    Omnivore 4 to 6 times body length
    Herbivore 10 to more than 12 times body length √
    Human 10 to 11 times body length √


    Carnivore Sharp claws
    Omnivore Sharp claws
    Herbivore Flattened nails or blunt hooves √
    Human Flattened nails √

  16. like no offense or anything, but i believe that not all people have to be meat eaters and i don't think we evolved from apes. i am a vegetarian and as healthy as can be. they put a lot of junk in meat.

  17. I think that when you eat less meat, so killing less animals, that are treated horribly, you are more prone to be happier

  18. Regardless if we are omnivores or herbivores, it is not necessary for humans to consume meat in the modern world. So why do we? If it is ethical, manageably healthy and better for the environment to be a vegetarian/vegan why not? It is not hard to commit yourself to not eating meat. We are just lazy.


    Research, my friend.

  20. Its called survival and no matter what any one wants to debate its very simple.

    We can digest meat, vegetables, fruits, and nuts.

    We cannot digest most leaves or grasses.

    Number one cause of food poisoning is not from meat but from shellfish, fruits and vegetables.

    Eating too much of anything is not good for you. Fruits are high in calories and can also lead to obesity.

    Beans until recently were not even edible.

    Like anything eat it is moderation and you will be fine.

    Another theory is that the intelligence gained by man may not have even been possible if it was not for the consumption of meat. Of course this is debatable.

    I don't think we are either vegetarians or meat-eaters. I think we are survivors and eat what is available to us to survive. We have the ability to cooks food and eat a variety of things.

    I also think you only live once and should do what you want and enjoy life. You won't get anywhere trying to prove that you're right be saying we are either vegetarians or meat-eaters because it is very simple today we are omnivores. Who really cares what we used to be. Your not going to change anything.

  21. Hey guys its theme is very interesting and I think we should put more information ... thanks for letting me comment

  22. Snigdha, you are completely misleading. No one ate horse after the yagna. By nature, human beings are strictly fruit eating beings. Simple logic... without smearing with spices or cooking or at the very least barbequing, does anyone feel like eating meat? No... but you feel like eating a banana or a mango or an apple.. that is your natural taste. So by nature, human beings are vegetarians

  23. Hello .. firstly I would like to send greetings to all readers. After this, I recognize the content so interesting about this article. For me personally I liked all the information. I would like to know of cases like this more often. In my personal experience I might mention a book called Generic Viagra in this book that I mentioned have very interesting topics, and also you have much to do with the main theme of this article.

    1. Yes we do. One of the most tasty pieces of empathy I've ever had was from a pig we had killed just minutes prior, completely raw. It was still warm.

  24. I think the people of India have a bad habit of creating division in everything, caste, religion, and the same goes for food also. Many vegetarians feel that proud about themselves and look down upon people who eat meat. funny thing is even many non veg eating people feel guilty about eating non veg. A very important hindu priest said in a tamil talk show said," there is no problem if people choose to eat non veg, no need of making it a big deal." now thats one wise man because what people eat is their wish. I think India is the only country where in non veg eaters are looked down by the veg eaters.
    human beings at first used to hunt animals and eat them, after many many years when agriculture was discovered only people started eating veg food.

  25. @jeffersontom
    It is usual misconception about anything that is Indian.
    Sujai gives an impression that he is a byword on every subject he writes.
    But it is not fair on your part to project his view as that of India.
    Coming to actual point of meat eating.
    Nothing Indian or Hindu or Islamic ever preached meat-eating is wrong. Nor meat-eaters are looked down.
    It is only Brahmin not supposed to eat meat. Here too the reason is not about Himsa/Ahimsa.
    Brahmin should recite the mantra correctly during rituals.
    It is believed that regular meat-eating spoils diction. I do not have any scientific proof for it. But it is believed so.

  26. In principle, a good happen, support the views of the author

  27. This article is totally hapless. If you want to listen to a totally scientific treatise on whether human being is herbivorous or not, watch this video. Not to deny greatness of Sujai. He is mostly great but in a few cases like these...

  28. As a doctor of Liverpool university and a vegan myself I have studied this topic for years and I still have not come up with a conclusion. humans can live a very healthy life ad a vegan without meat, dairy, eggs and honey etc. but we could just live off meat. but in the end it come to choice and who am I to tell you what to eat but morally, think about it.


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