Asking people what they ate is a very unreliable way of knowing what they actually eat. A better method used by paleoanthropologists who simply can’t ask the question, involves using skeletal remains. Those bones accumulate special kinds of atoms, called ‘stable isotopes’, serving as a sort of dietary signature. How is that? Because plants contain different distributions of isotopes than animals do, and we accumulate those different isotope patterns depending on what we eat. Amazingly, we can know more than just ‘plants vs animals’, we can also distinguish between different kinds of plants, and between marine versus terrestrial animals. So what does the stable isotope evidence tell us about humans?
Humans were as carnivorous, if not more so than wolves and hyenas [21,22] ! We also seemed to eat more terrestrial than marine animals.
Some people see this diet and immediately think that it is rooted in the same kind of extremism as veganism, but the two are quite different. It should be noted that veganism has its roots in religion, unlike carnivory, and this matters . The most prominent and vocal vegans are vegans for reasons other than health. They are striving for an ideal that has no empirical basis, only a value judgment. To this kind of vegan, eating animals is morally wrong and therefore any exception to it is a moral transgression. This means that the more you approach the ideal the better person you are. Just like other morally based systems of thought, it often leads to outrage about the behaviour of others, and political action to try to control this, sometimes including violence and vandalism. The carnivore diet has a sound evolutionary basis. It’s based in empiricism and practical concerns. The “purest” version of a carnivore diet is adopted for a trial as a baseline, to determine whether and to what degree plants are causing negative reactions in someone’s health. Purity here refers to a well-controlled scientific experiment, unlike purity in the vegan context which is a moral judgment. Foods are avoided based on a cost-benefit analysis informed by personal experiment. If someone decides to eat something they desire that causes them pain or disease symptoms, this is not considered an immoral act, nor anyone else’s business.
There are certainly vegans who are motivated by health rather than ethics. This kind of vegan is much more similar to a carnivore, because his or her beliefs are rooted in a combination of their interpretation of the science and personal experience. And they are similar, too, in that they are willing to take lengths for their health that cause them social inconvenience.