Are humans omnivores or herbivores?
Most humans are behavioral omnivores, but are we naturally so? Are we fit for eating meat and cheese as much as fruits and vegetables? Or are humans natural hervivores? Or maybe even carnivores?
Omnivores are organisms that feed on both animal tissue and plants.
- The vast majority of humans practice an omnivorous diet, and many live a long health life.
- Humans have been eating considerable amounts of both animal and plant matter for millions of years.
- Humans wean earlier than herbivores, a pattern that matches that of carnivores.
- Human omnivory is a cultural universal, making it part of the human species as a whole.
Herbivores are organisms that feed exclusively or mainly on plants.
- Our closest evolutionary cousins (chimpanzees, bonobos, gorillas) are all herbivores.
- All great apes are actually omnivores; they're plant-biased omnivores, hence the confusion.
- Humans lack claws, sharp teeth or other natural weapons.
- Our evolutionary adaptation is our brain, namely to make suitable weapons and strategies; this adaptation is a valid evolutionary strategy, and should not be discounted. Complex tool-making is intrinsically part of the human species.
- Humans have long intestinal tracks (8 times body length) while carnivores have short intestinal tracks (6 times body length).
- This only implies that humans are not carnivores, not that humans aren't omnivores.
- Herbivores' intestinal tracts are 12 times body length, and only go up from there. We are closer to carnivores than we are to herbivores in this regard.
- Humans can't derive energy from cellulose due to a reduced cecum and colon; all other herbivores and plant-biased omnivores (e.g. great apes, pigs) can do this.
- Humans require vitamin B12 in their diet, unlike herbivorous animals which can make their own in their colon with the help of bacteria.
- Humans have a 3 times reduced ability to synthesize taurine compared to herbivores.
- Humans selectively absorb heme iron in the small intestine with specialized receptors, which no herbivore does.
Notes and references
- Humans are not hervibores - Vegan biologist argues humans are omnivores
- Are humans omnivores, carnivores or herbivores? - Video discussing the issue
- Image comparing the mouth and teeth of various species of animals