9 of the 20 amino acids required by the body to create proteins translated from DNA come only from consumption since your body can't synthesize them (and some of these come strictly from meat). Proteins control... well, every biological aspect of you as a person and if you don't take in all of these amino acids in sufficient quantities, your body will turn on your muscles and break down the proteins there in order to find the needed amino acids.
In other words, enjoy meat. It's good for you.
It’s easier to get the essential amino acids from most meats since most have all 9. You can still get all essential amino acids (the kind your body must get from consumption) from non-meat sources. But no one source will have all of them. So vegetarians must make sure their variety covers all of them. Completely possible to get all from non meats.
That being said, meat is yummy.