Reply #177: Indeed, if we tried to eat like a cow, we would starve to death.

[Crunchy Frog]

Complex animals are not able to digest cellulose, which is the major component of cow food. Cows have very complex digestive systems which are filled with cellulose digesting bacteria, with which they have a symbiotic relationship. Humans do not have a gut which is capable of sustaining this kind of internal ecosystem, hence the cellulose that we eat goes right through us.

I don't know why people here keep argueing that humans are somehow classical herbivores, and therefore somehow akin to hooved mammals. Humans are primates. We have primate teeth, primate digestive systems, and primate food preferences. Your basic primate is evolved to eat a variety of largely plant based foods, but more of the fruit, nut, bud, type, and supplemented with animal protein from invertebrates and occasional small animals.