It is not unusual to hear the claim that humans are "omnivores", even authoritative text books and research papers use this term. Unfortunately, although sounding scientific, the meaning of this term is somewhat vague. On the one hand, the term omnivore can simply be used to describe animals that eat plant or animal foods, and on the other, it may be used to infer that an animal is biologically adapted to consume both plant and animal foods, and perhaps, that it is supposed to do so. A broader, and perhaps more appropriate definition of an omnivore, would refer to animals than can consume all kinds of food. This is because omni derives from the latin omnis meaning all.
Therefore, in common use, the term omnivore may be used to describe both a) what an animal does and b) what an animal is. Clearly humans can be said to be omnivores in the sense that they do eat both plant and animal foods, but this is just a truism. As an example of the contrast between is and does, cattle consume animal remains in contemporary farming practices, yet cattle are still considered to be herbivores - though they could be said to be omnivores in that they can eat an omnivorous diet.
This article addresses the suggestion that humans are biologically omnivores, because this is what people infer when they say "humans are omnivores".
