You're throwing another being's flesh away so it may be disposed of at a waste site. That strikes me as incredibly disturbing and completely messed up.
How does eating it make it any better. Having killed, you eat it, throw it, do anything else - nothing changes the fact that it was killed. And like the first post mentioned, we are not talking about facing starvation in jungle where we have to kill. Eating is just as bad as throwing it. But that is not what geoff referred to probably, he makes a point about people wasting when many are starving, not specifically meat.
