Humans are supposed to eat meat. Had pre-man and early man not developed into meat eaters, the human race would not have developed a high level of intelligence. Meat is nutritionally dense, while plant matter is nutritionally sparse. Eating meat gave man time to do other things like developing tools and other technological innovations.
Animals that eat only plant food have to graze most of the time to get enough nutrients. Compare a cow to a lion. A cow has to graze all day, while a lion may eat only 2-3 weeks.
Sez you. Man was created a vegitarian, and the pre-flood earth, a worldwide greehouse, produced enough nutrients in plant matter to support a healthy diet. Post flood, however, meat was on the menu, because the vapor canopy was gone, nutritious food was reduced significantly, and meat was protein rich. Ask the dinosaurs, they went exticnt because of it!