I heartily enjoy eating meat. I consider animal products to be the ultimate human food where “ultimate” means that for me to recognize a food-pairing as a meal, it must contain meat.
My feelings on food are typical even as they are no doubt heavily-influenced by American culture. Nevertheless, I suspect that most humans feel similarly. It’s for this reason that most of us meat-eaters raise a brow, groan, or otherwise strike a perplexed pose when encountering friends, family members, or acquaintances who choose not to eat meat. We intuitively don’t get it. I believe this is because avoiding animal products fundamentally goes against our biologically-formed nature.
For sake of discussion, I lump all non-meat-eaters into the category vegetarians recognizing this fails to recognize any number of distinctive differences!
Though some meat-heads can be intolerant of vegetarians, for the most part us carnivorously-inclined humans simply resign to rolling our eyes and not asking too many questions. Live and let live, so to speak.
However, even as we can all be tolerant to differing viewpoints on nutrition and food, as we learn more about our evolutionary past, which is to say our own biological predisposition, certain conclusions become unavoidable. One of those conclusions is that human beings have been selected via evolution to eat animal products. How do we know this? Well, it merely takes looking at our evolutionary preceptors and acknowledging that if they were omnivorous or carnivorous, it’s highly probably that we should be, too.
What do we see in our past? The second closest ancestors to modern humans, the Neanderthals, managed to “stick around” (not die out) up until around 30,000 years ago — these were the now-extinct neanderthals. Did they eat only plants? No. Neanderthals “were basically carnivorous” (See Stephan’s in-depth write-up, partially quoted below). Furthermore, you have to go a very long ways back to find any preceptor to Homo Sapiens that came close to being a vegetarian — chimpanzees branched off from the Homo genus some five million years ago!
Whatever reason for choosing vegetarianism, it really doesn’t matter to the following conclusion: choosing vegetarianism requires ignoring or rejecting human biology. This doesn’t make it wrong to choose vegetarianism; it just doesn’t jive with our genetics. Avoiding animal products in your diet may put your health at risk.
The question vegetarians should ask themselves is: is it worth risking their health to maintain adherence to a life-paradigm or morality that is in direct conflict with their biological nature?
I believe we will achieve considerably more coherence within our chosen morality if that morality is built with a firm grasp of human nature. That we are intended* to eat animals is part of that nature.
If you look at the chart above, Homo rhodesiensis (typically considered a variant of Homo heidelbergensis) is our closest ancestor, and our point of divergence with neanderthals (Homo neanderthalensis). Some archaeologists believe H. heidelbergensis was the same species as modern Homo sapiens. I haven’t been able to find any direct evidence of the diet of H. heidelbergensis from bone isotope ratios, but the indirect evidence indicates that they were capable hunters who probably got a large proportion of their calories from meat. In Europe, they hunted now-extinct megafauna such as wooly rhinos. These things make modern cows look like chicken nuggets, and you can bet their fat was highly saturated.
H. heidelbergensis was a skilled hunter and very athletic. They were top predators in their ecosystems, judged by the fact that they took their time with carcasses, butchering them thoroughly and extracting marrow from bones. No predator or scavenger was capable of driving them away from a kill.
Our closest recent relative was Homo neanderthalensis, the neanderthal. They died out around 30,000 years ago. There have been several good studies on the isotope ratios of neanderthal bones, all indicating that neanderthals were basically carnivores. They relied both on land and marine animals, depending on what was available. Needless to say, neanderthals are much more closely related to humans than chimpanzees, having diverged from us less than 500,000 years ago. That’s less than one-tenth the time between humans and chimpanzees.
I don’t think this necessarily means humans are built to be carnivores, but it certainly blows away the argument that we’re built to be vegetarians. It also argues against the idea that we’re poorly adapted to eating animal fat. Historical human hunter-gatherers had very diverse diets, but on average were meat-heavy omnivores. This fits well with the apparent diet of our ancestor H. heidelbergensis, except that we’ve killed most of the megafauna so modern hunter-gatherers have to eat frogs, bugs and seeds.
*As much as a blind or natural process like evolution can “intend” anything.