It's natural for animals to eat meat. You can't deny the predatory nature of life and the need for life to consume life. Plants are also living things that can suffer. Not eating meat is as stupid as not eating plants. It is nutrition that can sustain life, life eating life is how nature works.
Fallacy Of Is To Ought
Saying what is ("it’s natural", "it is how nature works"), as an argument about what ought to be.