# Humans are not omnivores



## Grandmaster Yoda (Jan 18, 2014)

I was considering this idea that humans are really herbivores as some have suggested based on digestion time and tooth shape. But at the same time I'm wondering what criteria exist to determine whether or not an animal is any of these "vores"? Much of the argument was "relative to carnivores humans digest much slower", but why aren't humans evaluated by criteria rather than comparison? If such is the case what criteria determines those carnivores to be carnivores that can't be used with humans? If it's that they eat meat, well so do humans. Is being an omnivore a thing derived from nature or through experience? It seems that when I tried to figure this out, the websites that stated that humans are herbivores were mostly headed by vegans and vegetarians, how could I ensure that they are telling the truth? What is the scientific view? What is the criteria? What is?


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## Blue Soul (Mar 14, 2015)

The fact that there are some people who are vegans or vegetarians doesn't change humanity's status as omnivores. Being an omnivore means that the individual's species normally acquire energy from multiple different sources. These sources could be plants, algae, fungi, meat or other products from animals. Since humans are omnivores, and vegans are humans, therefore even a vegan is an omnivore by definition. You could probably extend it to saying that this particular indivdual is maintaining a herbivorous lifestyle though, for example.

For scientific evidence, the teeth of different species can be compared. It's common that herbivores have broad, flat teeth, and that carnivores have sharp, sometimes jagged teeth. Some teeth, like a big cat's canine teeth are good for puncturing the throats of their prey, while something like a shark's saw-like teeth are better for ripping off chunks of meat. Human teeth seem to combine elements of both sharpness and flatness, suggesting that the ancestors of the primates once were mainly herbivorous and then shifted into including meat as a protein source as well. Human jaws are smaller than those of our other primate relatives to give room for larger braincases.

A major proof against humanity being herbivorous is our ineffectivity at digesting cellulose, the long sugar strands (polysaccharides) which make up the biggest part of plants. It is simply more effective for us to mix our energy sources than to rely solely on plants for food. Seeing how worldwide trends regarding meat consumption and overpopulation are going though, humanity could probably benefit from increasing the amount of plant foods in our diet and lowering the amount of meat we consume.


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## TheProphetLaLa (Aug 18, 2014)

Does it really matter either way? Maybe we were herbivores and then became omnivores. Maybe we were always omnivores. None of this stops us from becoming herbivores if we really wanted to.


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## Roman Empire (Oct 22, 2014)

I wish you good luck you have decided to enter one of the topics that shouldn't be discussed with people.

- Religion
- *Diet*
- Politics

To name a few.

People who speak religiously about these topics always remind me of the loony people talking about their UFO sightings. 

Have fun :wink:


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## prplchknz (Nov 30, 2010)

we are omnivores, i'm really tired of people trying to claim we're herbivores if that was the case meat would not provide the nutrients it does and we would not be able to survive off of it, but we can. we can also survive off vegan and vegetarian diets, but you feed a cat a vegan diet it will die because they are carnivores, and pushing vegetarianism is really annoying imo. you want to be a vegetarian be one, I don't care. But don't use pseudo science to convince everyone else to be. if we were truly herbivore then i'd think it wouldn't be so hard for us to get complete nutrietion from vegetarian/vegan diets, but it is. the fact that it takes effort to get enough of the required protein from vegan diet (not saying it's impossible) also like @Blue Soul said look at are teeth we have canines (not as prominent as some animals) which is used for meat eating and then we have molars which is found in herbivores and is good for breaking down plant base material. if we weren't ominvores why would we evolve to have those things?

Dental and Skull Anatomy of Carnivores, Herbivores, and Omnivores <---Teeth things


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## Grandmaster Yoda (Jan 18, 2014)

TheProphetLaLa said:


> Does it really matter either way? Maybe we were herbivores and then became omnivores. Maybe we were always omnivores. None of this stops us from becoming herbivores if we really wanted to.


I'm not asking to change things, just how we understand them and if we don't understand them how do interpret change between these classifications?


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## QuiteCharmed (Oct 10, 2014)

I think that over time our bone structure has evolved to accommodate an omnivorous diet. However, I do think there are a lot of benefits to remaining as herbivores


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## Flaming Bassoon (Feb 15, 2013)

We previously were much more herbivorous (though not exclusively), which is what wisdom teeth were used for -- chewing plants is usually much more difficult.


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## PowerShell (Feb 3, 2013)

If we were supposed to be strict herbivores, how come vegans have to supplement their diets to get everything they need? Theoretically, we should be able to get every nutrient our bodies require with a balanced diet and no supplementation.


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## Lady Isla (Feb 20, 2015)

Some of you may find this interesting. I had to a Google a site for the exact references, but I recalled reading that according to the Bible people were originally herbivores. The change is said to have occurred after the Great Deluge. I'd be interested in learning if this is mentioned in other versions of the Great Deluge event from Mesopotamia.
Search For Bible Truths: Did Humans Eat Meat Before The Flood?



> Genesis 9:3 (NIV) - Everything that lives and moves about will be food for you. Just as I gave you the green plants, I now give you everything.


At any rate some food for thought.


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## Kavik (Apr 3, 2014)

If humans were herbivores they wouldn't get sick on plant only diets. A deficit of what meat provides causes weakness, dizziness, and brain fog. In an extreme case nerve damage can occur. Likewise, only eating meat isn't a great idea since the likes of calcium and magnesium will be absent from the diet. We all known vitamin C comes from a variety of fruits and vegetables and without it scurvy occurs. Humans have to be omnivorous to be healthy. 

Strict vegetarians or meat eaters can't be on a diet that swings only one way or the other without getting artificial help. Also, dentistry is a surefire way to know what types of food an animal eats/ate. 

Being an omnivore might possibly be an evolutionary trait. I would be interested in seeing gradual dental records dating from ancient times.


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## Desolan (Nov 14, 2011)

I've heard it stated that the length and properties of the Monogastric Digestive System in mammals, as people have, can determine whether it is designed for a herbivore or carnivore diet, And that the properties of a human digestive tract is more akin to that of other mammals that are herbivores.

In both cases though, the Monogastric Digestive System relies on highly digestible feedstuffs that are high in energy and lowin fiber, and since meat meets this criterea this doesn't exclude any herbivore with this digestive system from eating meat. It can however be dangerous for us and these herbivores due to the harmful bacteria and parasites that raw meat can be infected with, as carnivores have stronger stomach acids that destroy these pathogens. Luckily for man though, we have lived near fire for thousands of years and cooking this meat solves this problem for us.

So I would say that all monogastric digestive system animals can eat meat, but some have adapted to it more strongly than others. And in the case of carnivores this adaptation has actually resulted in the inability to digest the more vegetative foodstuffs that require more time to process and break down.


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## ScarlettHayden (Jun 8, 2012)

If people are not omnivores then why do we eat a mixture of plant and animal life?

Rhetorical question.


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## aendern (Dec 28, 2013)

I have seen convincing comparisons of human teeth with carnivorous teeth, herbivorous teeth, omnivorous teeth and frugivorous teeth. 

Our teeth undeniably match those of frugivores the closest. 

But I agree with you--what constitutes an omnivore? Should it really be based on comparison with other animals, or is lifespan (and overall success on a dietary lifestyle) more valuable information?

I think it's pretty common knowledge by this point that humans do best on diets rich in fruits, vegetables, whole grains, and some nuts and seeds. 

Fish are also part of the diets of those with the longest lifespans in the world. (See: the Japanese)


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## Macrosapien (Apr 4, 2010)

Blue Soul said:


> The fact that there are some people who are vegans or vegetarians doesn't change humanity's status as omnivores. Being an omnivore means that the individual's species normally acquire energy from multiple different sources. These sources could be plants, algae, fungi, meat or other products from animals. Since humans are omnivores, and vegans are humans, therefore even a vegan is an omnivore by definition. You could probably extend it to saying that this particular indivdual is maintaining a herbivorous lifestyle though, for example.
> 
> For scientific evidence, the teeth of different species can be compared. It's common that herbivores have broad, flat teeth, and that carnivores have sharp, sometimes jagged teeth. Some teeth, like a big cat's canine teeth are good for puncturing the throats of their prey, while something like a shark's saw-like teeth are better for ripping off chunks of meat. Human teeth seem to combine elements of both sharpness and flatness, suggesting that the ancestors of the primates once were mainly herbivorous and then shifted into including meat as a protein source as well. Human jaws are smaller than those of our other primate relatives to give room for larger braincases.
> 
> A major proof against humanity being herbivorous is our ineffectivity at digesting cellulose, the long sugar strands (polysaccharides) which make up the biggest part of plants. It is simply more effective for us to mix our energy sources than to rely solely on plants for food. Seeing how worldwide trends regarding meat consumption and overpopulation are going though, humanity could probably benefit from increasing the amount of plant foods in our diet and lowering the amount of meat we consume.


I don't think teeth are a great example here. The other apes are primarily herbivores, with about 10% give or take protein from bug eating. Chimps are know to eat a certain species of small monkey for a season. But they are primarily herbivores and they have huge canines, our's are absolutely pathetic. Unlike carnivores we can not tare through the hide and flesh of a living animal with our teeth, we do not have the biological tools, which suggests that we can do this. If we were to kill an animal and just attempt to eat it on the spot, with it bleeding out, more than likely you'd get sick and die. Of course, under special conditions, when you raise your animals (or you buy the meat from a good source), and prepare the flesh and such probably, it can be eaten raw, at least some types of meat. But to return to the other apes and their large canines, Gorillas, unlike the chimp, except the bug eating, is a herbivore. Those huge canines would suggest that they are to eat meat, however, their strong teeth may be in the form they are to support their consumption of coarse vegetation. 

I'm happy you mentioned the molecular structure within the plant, the cellulose, which is hard to digest. This mostly applies to raw vegetables, by cooking the vegetables, there is a breaking down of the cellulose structure, which helps to further absorb the nutrients. Also, if cooked with certain oils, or mixed with certain other foods that contains certain vitamins, when mixed together creates more nutrient absorption from the vegetables. For instance, Spanish, if mixed with a vegetable or fruit, that contains vitamin C, it increases the degree at which one can absorb IRON from Spanish. Also, the breaking down of cellulose, is why we have teeth, it just means to get the most out of the vegetable you have to chew it really really well. And all of our teeth is useful in the chewing of greens, especially if they are raw, even the canines, to essentially tare through them But of course our molars and other back teeth, like the unnecessary wisdom teeth. But we aren't like cows and deers, we don't eat grass, we can't digest that. Through eating those animals, we get the nutrients from their meat. However, the the diet of the other apes does suggest something about us, that we should be eating a lot more greens, which is roughly, the thing they eat the most in their diet. Our meat consumption should be very low, as low as the apes bug protein. If we look at food proportion, there is only one part of it that we can eat unlimited amounts of without ill effect and that is vegetables. But greens can have an ill effect given that you have to rotate them, if you eat a lot of them.

Mind you, I recognize that you admitted that we could lower our meat consumption and raise our plant food consumption. My post is primarily about certain points. I don't get into the whole debate on what a human is in relation to diet, I think a person can eat whatever they want, but if they want to optimize their health, then they will be mostly vegetarian, eat meat, but in the right proportion. In a vegetarian mind you, I know the usefulness of meat. It's just a very convenient source of food. In terms of survival, eating meat just makes more sense, in real survival situations -- or nomadic lifestyles. A person can survive for the most part solely off of eating meat, where as solely off of plant food, would be more technical, due to B12 and the omega fatty acids (which can be substituted with flax seeds, chia seeds, and hemp). Although B12 would be less difficult, if our food was dirtier, but who would sacrifice cleanliness, for B12. So believe me, this post is not a debate posts, meat is a very viable source of food. The over consumption of it is a problem, but it doesnt mean one has to stop eating it.


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## Macrosapien (Apr 4, 2010)

Kavik said:


> If humans were herbivores they wouldn't get sick on plant only diets. A deficit of what meat provides causes weakness, dizziness, and brain fog. In an extreme case nerve damage can occur. Likewise, only eating meat isn't a great idea since the likes of calcium and magnesium will be absent from the diet. We all known vitamin C comes from a variety of fruits and vegetables and without it scurvy occurs. Humans have to be omnivorous to be healthy.
> 
> Strict vegetarians or meat eaters can't be on a diet that swings only one way or the other without getting artificial help. Also, dentistry is a surefire way to know what types of food an animal eats/ate.
> 
> Being an omnivore might possibly be an evolutionary trait. I would be interested in seeing gradual dental records dating from ancient times.


Well the only things in meat that are not in plants, are B12 and omega fatty acids. But these are in other sources, seeds and dairy, if one wants to eat it. B12 isn't produced by animal flesh, it's a bacteria, it comes from things being dirty, and animals consuming it. 

I'd disagree that humans have to be omnivorous to be healthy, I know a lot of vegans who are really healthy. Their only problem is B12, and they go the supplement route, but so does meat eaters these days. Most people, in general, take vitamins to be "healthy" anyways, because their normal diet is not varied enough to ensure optimal health. The omnivore, for instance, should eat way more vegetables and greens, a moderate to minimal amount of meat, to be consistent with proportion -- but no one eats like this, except probably the Japanese. Likewise, we need more than just vegetables and meat, but also a variety of probiotics and prebiotics, which is what Japanese tend to eat on a regular. So it's a wide range of dietary habits that equals optimal success, to pin them on one thing when it is a variety is sort of misguided. This mistake is often made by vegetarians as well. Most people out there are not optimally healthy, primarily, regardless of dietary habits. Mind you, the strict vegetarian, is often more healthier, because they have to be more aware of what they eat, or they can get really sick Lol, so they have to learn.


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## Kavik (Apr 3, 2014)

Pseudonymity said:


> Well the only things in meat that are not in plants, are B12 and omega fatty acids. But these are in other sources, seeds and dairy, if one wants to eat it. B12 isn't produced by animal flesh, it's a bacteria, it comes from things being dirty, and animals consuming it.
> 
> I'd disagree that humans have to be omnivorous to be healthy, I know a lot of vegans who are really healthy. Their only problem is B12, and they go the supplement route, but so does meat eaters these days. Most people, in general, take vitamins to be "healthy" anyways, because their normal diet is not varied enough to ensure optimal health. The omnivore, for instance, should eat way more vegetables and greens, a moderate to minimal amount of meat, to be consistent with proportion -- but no one eats like this, except probably the Japanese. Likewise, we need more than just vegetables and meat, but also a variety of probiotics and prebiotics, which is what Japanese tend to eat on a regular. So it's a wide range of dietary habits that equals optimal success, to pin them on one thing when it is a variety is sort of misguided. This mistake is often made by vegetarians as well. Most people out there are not optimally healthy, primarily, regardless of dietary habits. Mind you, the strict vegetarian, is often more healthier, because they have to be more aware of what they eat, or they can get really sick Lol, so they have to learn.


When I say 'must be omnivorous to be healthy' I'm talking about a diet without vitamin pills and what humans are biologically. Vegetarianism is a lifestyle choice, it doesn't change the fact the vegetarian is still an omnivore. If you only feed a lion plants and add in supplements it's not going to suddenly be classified as a herbivore.


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## Macrosapien (Apr 4, 2010)

Kavik said:


> When I say 'must be omnivorous to be healthy' I'm talking about a diet without vitamin pills and what humans are biologically. Vegetarianism is a lifestyle choice, it doesn't change the fact the vegetarian is still an omnivore. If you only feed a lion plants and add in supplements it's not going to suddenly be classified as a herbivore.


My post was not debate the whole omnivore thing... I could if I felt like it, as this is not the first time I have encountered a debate. But anyone can find any information to support their argument or perspective of things, so I don't waste my time with it. I'll just say this, if you feel humans are omnivores, fine, but they are far far far more on the herbivore side of the spectrum than the carnivore when we consider the digestive system. Anyways, these type of discussions usually break down this way, where a person will suggest that anything that can eat meat is an omnivore, even if it is vegetarian by nature. To the thread starter, the reason we make comparison, is to find an objective rationale, that does not depend on opinion. It's the reason why I can't think the bone holding my back together is a broomstick. We can look at other beings, or animals and we see patterns of similarity, than we classify based on these patterns, and how within these patterns are produced certain functions of our physiology. In a sense, we know ourselves through by observations and studying of beings with similarities to us. We are mammals and as mammals we share certain commonalities. When it comes to diet, we can make comparison, if we approach diet from a base function, i.e. just from what nature allows, not what we have created. A carnivore is a carnivore due to their bone structure, their digestive structure, the ph of their stomach, among other things. They are, by nature, intricately to be physically capable to stalk down their food and eat them on the spot. The characteristics suggest what it is in terms of diet. When people call humans essentially herbivores they are doing the same type of reasoning to suggest this.


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## Macrosapien (Apr 4, 2010)

emberfly said:


> I have seen convincing comparisons of human teeth with carnivorous teeth, herbivorous teeth, and frugivorous teeth.
> 
> Our teeth undeniably match those of frugivores the closest.
> 
> ...


But how much of that longest lifespan is fish based, as much as it is other things as well? I think it just suggests a more whole diet. There is not only fish being eaten, but Probiotics and Prebiotics.... the importance of probiotics is often not taken into consideration and there is a lot of food, I believe, that is fermented in their diet. I wonder is it possible to accurately measure which part of the diet is having the most profound effect on a diet that is known for being healthy.


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## Red Panda (Aug 18, 2010)

Our teeth anatomy is closest to frugivores and our ancestors were frugivores. However, we've been eating pretty much anything, including meat for ~2 million years, so we are basically omnivores.

What sets us apart from other animals and it seems that many militant vegans forget is that we COOK and we use TOOLS. So we don't need carnivorous, or even other omnivorous teeth and appendices (cause I've seen the argument that we don't have claws.. lol). Our whole heads have evolved since the time we discovered cooking, our brains got bigger and smarter because we didn't need as much time and space to chew as we did and as other primates do. Comparative anatomy is useful, but we are also unique in the animal kingdom so it can go so far.

And since I brought up the issue of vegans, here's a sensible one


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## Red Panda (Aug 18, 2010)

Pseudonymity said:


> Well the only things in meat that are not in plants, are B12 and omega fatty acids. But these are in other sources, seeds and dairy, if one wants to eat it. B12 isn't produced by animal flesh, it's a bacteria, it comes from things being dirty, and animals consuming it.
> 
> I'd disagree that humans have to be omnivorous to be healthy, I know a lot of vegans who are really healthy. *Their only problem is B12, and they go the supplement route, but so does meat eaters these days.* Most people, in general, take vitamins to be "healthy" anyways, because their normal diet is not varied enough to ensure optimal health. The omnivore, for instance, should eat way more vegetables and greens, a moderate to minimal amount of meat, to be consistent with proportion -- but no one eats like this, except probably the Japanese. Likewise, we need more than just vegetables and meat, but also a variety of probiotics and prebiotics, which is what Japanese tend to eat on a regular. So it's a wide range of dietary habits that equals optimal success, to pin them on one thing when it is a variety is sort of misguided. This mistake is often made by vegetarians as well. Most people out there are not optimally healthy, primarily, regardless of dietary habits. Mind you, the strict vegetarian, is often more healthier, because they have to be more aware of what they eat, or they can get really sick Lol, so they have to learn.



Vitamin B12 deficiency in vegans is about 100% of the population unless they take supplements, whereas in omnivores it varies from 3-20% depending on age (the elderly are the most affected group). 

and to quote "Numerous other studies on smaller population groups confirmed that both vitamin B-12 intake and serum vitamin B-12 concentrations increase progressively from vegans to lactoovovegetarians, to those who consume fish or some meat, to omnivores (15–17)."
How common is vitamin B-12 deficiency?

Yes the average modern (american) diet is crap, but that's a different discussion than omnivore vs herbivore though.


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## Ik3 (Mar 22, 2015)

Based on the recent discovery that races of non African decent (European, Asian, Ect) posess Neanderthal DNA, and Neanderthals where almost exclusively carnivores, that might have something to do with the **** sapien sapien shift to an omnivorous diet. There could be other hominid species in our ancestral past that were exclusively herbivores. 

Sort of a "Mom's Catholic, Dad's Protestant" type situation...


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## Derange At 170 (Nov 26, 2013)

Our digestive tract is different from both carnivores and herbivores and is described as looking like it's somewhere in between either.

Our ancestors were already cooking meat, **** erectus. We compare the teeth of carnivores to human teeth, but we can't do that without understanding that they have a different fuction in humans than they do in carnivores. Carnivores use their teeth to hunt, attack and kill prey, Then they use their sharp teeth to rip away flesh from their prey.

Since we use weapons and tools for that goal (and have for more than a million years), our teeth do not need to be heavily specialized for killing and they're more than just well suited at tearing apart and chewing on cooked meat. These tools have been around for so long, that our bodies had ample time to adapt to our use of them. Our jaws have become smaller and less muscular since we've started using tools, for example.

We're solidly omnivores.


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## sorry_neither (Mar 21, 2012)

I'm just going to leave this link...

Comparative Anatomy Updated. Humans--Omnivores or Vegetarians?


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## MikeHesson (Apr 14, 2015)

Well to very extent it is quite right that human are not omnivores and they are addicted to few diets and they are not omnivores.


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## aendern (Dec 28, 2013)

I think ultimately it boils down to what you want to support with your money.

Can you be healthy on either lifestyle? Yes, absolutely. Anyone who says otherwise is either ignorant or intentionally trying to mislead you.

Can you be unhealthy on either lifestyle? Yes, absolutely. Anyone who says otherwise is either ignorant or intentionally trying to mislead you.


So then it's not about health. So what's it about? Well, if you look at the bigger picture . . . 

- The factory farming of livestock is one of the main causes of greenhouse gas emissions worldwide.
-- This source says nearly half of the world's methane emissions are from the livestock industry. Methane is twenty times more potent as a greenhouse gas than CO2 although it does not last as long in the atmosphere, eventually breaking down into CO2 and other gases. 

- Overfishing is leading to thousands of species of fish to become endangered and is altering oceans' ecosystems and food chains at a rapid pace. 
-- (v, w, x, y, z)

- Deforestation to make room for the expanding livestock industry makes up another factor that plays into global warming.
-- Cattle ranching accounts for 80% of the deforestation of the Amazon. (a, b, c) 


But still I think one could avoid these^ things while simultaneously eating animal flesh by simply 
1. supporting local farmers instead of factory-farm megacorporations
2. buying the flesh of organicly raised animals instead of that of non-organicly raised ones.
3. not eating fish that you didn't kill yourself.


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