For the protein.
Yes and no we need protein and many many plants such as soy provide that needed resource but we need meat becouse it gives us more protien for the build of mucle
We don't NEED to eat meat, but its cheaper and easier than a protein rich vegetarian diet. Despite the common AMERICAN view, we can get complete protein diets from vegetables. Soybean are the only complete vegetable protein so if you have a soy allergy you best stick with meats. Rich, green vegetables must be present for calcium and iron, but B12 (which is needed) is only present in meat. Best stock up on vitamins or eat the occasional fish. Just remember that a well rounded diet is far more important than any individual item.
The answer is we do not. We have the big protein myth dictated to us in the West and so do not bother to think this out. Most of the worlds strongest animals are vegetarian and so thet tells us that protein does not come solely from meat but comes from the ground in the first instance and that human meat eaters take it from higher up the food chain, causing much pollution and wastefulness. Big subject!
Because it is a great source of protein.
Because your gay