Carnivorous animals are aroused by the scent of blood and the thrill of the chase. Most humans, on the other hand, are revolted by the sight of raw flesh and cannot tolerate hearing the screams of animals being ripped apart and killed. The bloody reality of eating animals is innately repulsive to us, more proof that we were not designed to eat meat.
Does the sight of a dead bird make you salivate? Do you daydream about killing cows with your bare hands and eating them raw? If you answered "no" to all of these questions, congratulations--you're a normal human herbivore--like it or not. Humans were simply not designed to eat meat. Humans lack both the physical characteristics of carnivores and the instinct that drives them to kill animals and devour their raw carcasses.
Cats are obligate carnivores (they must live on a diet primarily of meat) and their taste buds reflect this by having abandoned the tongue sensors that respond to sweet-tasting carbohydrates. Dogs are omnivores (they have retained both kinds of taste buds) those enjoying carbohydrates and amino acids. Humans tongues respond pleasurably to sweet (carbohydrates), but have lost the taste for amino acids, placing us undeniably in the category of herbivores (plant eaters).
Many of your friends and family are confused, thinking people are omnivores, needing both meat and plants in their diet. We only appear to be omnivorous because we have the ability to "doctor up" meat with salt and sauces (barbecue, sweet and sour, marinara, etc.) sufficiently enough to make it palatable. Prove this for yourself.
The next person you meet head-on who claims meat is "tasty," stop him in his tracks and insist that he eat a large plate of plain, unseasoned, boiled beef or boiled chicken in front of you; note their displeasure. Then offer that same meal to the dog or cat and note how eagerly this critter devours the meat. You would be hard-pressed to find a person who did not enjoy a bowl of perfect, ripe bananas, but try to get your cat to eat this sweet food. I have a Rottweiler dog named Bodega who is a true omnivore and enjoys bananas as much as meat. A careful observer notices that an animal's taste buds are no mistake of nature—they clearly define the proper diet that the animal should eat.
Comparing humans to other animals
Human physiology is strikingly similar to that of other plant-eaters, and quite unlike that of carnivores. It is telling that in none of the missives that readers have sent in to argue with me do they ever deny the data in the following table. They simply think that by making some other point (e.g., that humans possess canine teeth) that somehow obliterates the more convincing data in the table. This is the same table presented at the beginning, but it's important enough that it bears repeating.
Humans are biologically herbivores
CarnivoresOmnivoresHerbivoresHumans
Facial musclesReduced to allow wide mouth gapeReducedWell-developedWell-developed
Jaw typeAngle not expandedAngle not expandedExpanded angleExpanded angle
Jaw joint locationOn same plane as molar teethOn same plane as molar teethAbove the plane of the molarsAbove the plane of the molars
Jaw motionShearing; minimal side-to-side motionShearing; minimal side-to-side motionNo shear; good side-to-side, front-to-backNo shear; good side-to-side, front-to-back
Major jaw musclesTemporalisTemporalisMasseter and ptergoidsMasseter and pterygoids
Mouth opening vs. head sizeLargeLargeSmallSmall
Teeth: IncisorsShort and pointedShort and pointedBroad, flattened and spade-shapedBroad, flattened and spade-shaped
Teeth: CaninesLong, sharp, and curvedLong, sharp and curvedDull and short or long (for defense), or noneShort and blunted
Teeth: MolarsSharp, jagged and blade-shapedSharp blades and/or flattenedFlattened with cusps vs. complex surfaceFlattened with nodular cusps
ChewingNone; swallows food wholeSwallows food whole and/or simple crushingExtensive chewing necessaryExtensive chewing necessary
SalivaNo digestive enzymesNo digestive enzymesCarbohydrate digesting enzymesCarbohydrate digesting enzymes
Stomach typeSimpleSimpleSimple or multiple chambersSimple
Stomach acidity with food in stomach≤ pH 1≤ pH 1pH 4-5pH 4-5
Length of small intestine3-6 times body length4-6 times body length10-12+ times body length10-11 times body length
ColonSimple, short, and smoothSimple, short, and smoothLong, complex; may be sacculatedLong, sacculated
LiverCan detoxify vitamin ACan detoxify vitamin ACannot detoxify vitamin ACannot detoxify vitamin A
KidneyExtremely concentrated urineExtremely concentrated urineModerately concentrated urineModerately concentrated urine
NailsSharp clawsSharp clawsFlattened nails or blunt hoovesFlattened nails
From
The Comparative Anatomy of Eating, by Milton R. Mills, M.D. * "Body length" measured from neck to anus, as with the other animals
As another writer said, "The human body was not designed to catch or eat animals. You have no claws. Your teeth do not rend flesh. Your mouth can not seriously wound nor is it made to really get a good bite into an struggling victim like true carnivores can. You are not fit to run fast to catch prey. Meat-eaters have fast enough reflexes to ambush or overtake a victim. You do not. Try catching a pig or a chicken with your bare hands; see what happens."
Plant-eaters have the longest lifespans
In general,
plant-eating creatures have the longest lifespans. Elephants, horses, and chimpanzees are at the top of the list while lions, tigers, and wolves are about half that. Humans' lifespans are even longer than the elephants etc. (even before modern medicine), providing more evidence that we're in the plant-eating camp.
Omnivores
Herbivores (least sleep)
Carnivores (most sleep)
We sleep like herbivores
Carnivores sleep the most, herbivores the least, and omnivores in the middle. Guess which group our own sleep correlates to. Here are some charts from
an article in Nature (PDF). They have arbitrarily stuck us (and other primates) in the omnivore group, because that's what everyone assumes we are, but notice that we're at the extreme end of that chart, with nearly every other single omnivore sleeping more than we do. We fit nicely in the herbivore chart, and I added a prominent dot for us in that one so you can see how we fit in at eight hours a night. If we use a figure of 6-7 hours a night (suggested as natural by
longevity research), our placement in the chart becomes even more compelling.
"But what about canine teeth and binocular vision?"
It's part of our collective consciousness that we have "canine teeth" and that this "proves" that we're meat eaters. But the truth is that this argument couldn't be weaker.
Canine teeth are canine in name only. Humans' so-called "canine teeth" are unlike the canine teeth of
actual canines, which are
really long and really pointed. Our teeth are absolutely not like theirs. In fact,
other vegetarian animals (like gorillas and horses) possess the same so-called "canine" teeth.
Overall, our teeth resemble those of plant-eaters much more than meat-eaters. For example, we have molar teeth (plant-eaters do, carnivores don't). Try to find a human-type molar inside your cat's mouth. Our teeth can also move side to side to grind, just like the other plant-eaters, and completely unlike the carnivores. Their jaws go only up and down.
My favorite counter to someone trying the canine rationalization on a message board:
"Hey Julia--we evolved with canine teeth? I'd like to see you tackle a steer and tear it apart with those ferocious incisors."
What's funny to me is how the teeth argument is
so important to meat proponents when they make their point about canine teeth, and then as soon as they find out that our teeth are much more similar to those of herbivores than of carnivores, and therefore consideration of our teeth suggests that we're designed to be plant eaters -- suddenly what kind of teeth we have is not so important to them after all.
Others have argued that predators have eyes on the front of their heads for binocular vision, while prey animals have eyes on the sides, indicating that we fall into the predator camp. This ignores the fact that the animals that we're
most similar to -- the other primates -- have eyes on the front of their heads, and are almost exclusively vegetarian. It's also important to remember what I said at the top of this article: There is certainly evidence on both sides of this debate, but the
preponderance of evidence clearly shows that we're suited to eating plants almost exclusively.
Does the unhealthfulness of meat mean that it's not natural?
The medical evidence is overwhelming: The more animal foods we eat, the more heart disease, cancer, diabetes, and other degenerative disease we suffer. This has been exhaustively demonstrated beyond any doubt. Dean Ornish, M.D. showed that
heart disease can be reversed, and he did so by feeding his patients a vegetarian diet.
John McDougall, M.D. has also written extensively about how the overwhelming scientific evidence shows that animal foods cause disease, and how for 25 years he's helped patients regain their health by eating unprocessed vegan foods instead. The science journals are filled with articles that come to the same conclusion: more plants means better health, more animals foods means more illness. And as mentioned earlier, the Maasai in Kenya, who still eat a diet high in wild hunted meats, have the worst life expectancy in the world. (
Fuhrman)
But is this evidence that meat-eating is unnatural? Maybe so, but maybe not. On the one hand we expect that's what's natural for us to eat should keep us in the best health (and that would discount meat, at least in the amounts it would take to make us true omnivores). But on the other hand, people can certainly live well beyond their reproductive years on a mixed animal-plant diet, which is mostly what evolution cares about. So it's hard to say whether the unhealthfulness of meat is evidence that we're naturally plant-eaters, but then again, we have other, better evidence anyway. The best evidence that we're supposed to eat primarily plants is the obvious one: our anatomy.
Human performance on meat-free diets
Not only do vegetarians and vegans easily build muscle, they often excel as athletes too, winning Olympic gold medals and world championships. In fact, some of the most famous bodybuilders in history were vegetarian. Here's a list of vegan and vegetarian athletes.
Examples of successful vegetarian and vegan athletes
(Note: As of July 2012, I've stopped adding to this list, because I've made my point that there are numerous vegans who among the top athletes in their sports. The number of vegetarian and vegan athletes is growing rapidly now and there's no way I'll be able to keep up with all the new ones. By the way, not all these athletes were/are exclusively veg*n for their entire athletic careers, the point is that they were/are successful as athletes even when veg*n.)
Vegan Bodybuilders
Some sites for vegan bodybuilders:
Vegan bodybuildersshatter the myth that vegans are skinny and malnourished.
(Pictured: Avi Lehyani, anonymous, Ryan Wilson, Robert Cheeke)
Vegan Powerlifters
- Noah Hannibal. Gold medal, heavyweight division of the Australian National Bench Press Championships
- Pat Reeves. 12-time British Masters Powerlifting champion
- Bill Mannetti. 1st place in division, Connecticut State Powerlifting Championship
- Joy Bush. 1st place in division, Connecticut State Powerlifting Championship
- Andrew Clark. 1st place in division, Global One IPF
- Joel Kirkilis. 1st place in division, Global One IPF and ANB Victorian Championships
- Patrick Virtue. 2nd place in division, Global One IPF
Other Vegan Athletes
- Carl Lewis (track) 2 Olympic gold medals as a vegan
- Scott Jurek (ultramarathoner) 7 consecutive wins at Western States 100 Mile Endurance Run, numerous other first place finishes and records
- Matt Frazier (ultramarathoner), runs NoMeatAthlete.com
- Scott Spitz (runner) Numerous 1st place finishes
- Tim VanOrden (runner) Numerous 1st place finishes
- Fiona Oakes (runner) 1st place woman and 2nd overall in a 2011 marathon
- Brendan Brazier (Ironman triathlete). Won the National 50km Ultra Marathon Championships
- Ruth Heidrich, (triathlete and marathoner) More than 900 first-place trophies and set several performance records. Named One of the 10 Fittest Women in North America.
- Dave Scott (Ironman triathlete) Six-time Ironman champion
Vegetarian Athletes
- Billy Simmonds (bodybuilder) Natural Universe champion
- Bill Pearl (bodybuilder) Mr. Universe (3 times), World's Best Built Man, Mr. America, Mr. California, numerous Halls of Fame
- Roy Hilligenn (bodybuilder) Mr. South Africa (4x), Mr. America, Olympic lifter
- Ricky Williams (football) Miami Dolphins
Amateur Vegan Athletes of note (except vegetarian where noted)
- Vegan Bodybuilders: Ryan Wilson, Ivan, Mike Mahler, Marvin Whittred, Jon Hinds, Charlie Abel, Mike Mahler: "Becoming a vegan had a profound effect on my training. … [M]y bench press excelled past 315 pounds...and I put on 10 pounds of lean muscle in a few months."
- Dan Attanasio (extreme calisthenics)
- Mike Eves (IKFF certified kettlebell trainer)
- Jeanie & Chelsea Ward-Waller, Stephanie Palmer. Bicycled coast-to-coast across the U.S. in 2012 to support safe bicycle routes in cities. They mentioned that they're vegetarian in a presentation I attended in March 2012.
- Jane Ward, M.D. Described herself as mostly vegan at a presentation I attended in March 2012. At age 60 in 2012, in the last four years she completed over 10 triathlons including a Half-Ironman, and is also a veteran of over 8 marathons and the 24 hour/50 mile Caledonian Challenge in Scotland.
- Michael Bluejay. I'm listing myself not because I'm an elite athlete (I'm not), but just to show that I put my money where my mouth is. As a vegan, I used to run marathons, and before a knee injury ruined my running career, my half-marathon time put me in the top 22% of male runners my age. After my injury, I started doing handcycle marathons. I won the handcycle division of the 2012 Austin Marathon, but there were no other entrants in my division. I hope to win next year's race against actual competition.
In this video, McDougall notes that Roman gladiators were vegan.
The research on veg vs. non-veg athletes is fairly sparse, but what does exist has failed to show any clear performance benefit for meat-eaters. (See my separate article,
Protein and Strength.)
Summary
- Human anatomy is much more similar to herbivores than carnivores.
- If humans are omnivores because we're capable of eating meat, then so are cats, since most cats eat plant foods every day. If we're supposed to eat animal foods, the evidence suggests it's a tiny part of our diets, not a large one.
- Making one contrary point does not magically invalidate all the other evidence as soon as it's made.