Cannibals All (or: You Eat What You Are)
Most forms of life on earth, including humans, lack the ability to manufacture internally all the chemicals needed to sustain themselves. To obtain these substances, they eat other creatures that can manufacture them. This happens all the way up the food chain. At the top we have ourselves, who eat just about anything, including vertebrates, crustaceans, plants, fruits, insects, the lot. Put differently, we eat our fellows who eat their fellows. And if that's not cannibalism, please explain what is, while I take time out to have some shrimp, mushrooms, and a nice pork chop.
Seriously, the best food, or at least the best protein, is that which is most like our own. Of course, eating others of our kind gives rise to social problems, and is rare as a result, but it happens. In times past, among some of the Pacific Islands peoples, since a butchered human very much resembled a butchered pig, it was referred to as "long pig". I presume these cannibals ate only their enemies, not their family members, no matter how tasty they may have looked. Most of us have accepted that humans are precious in the sight of God, while ordinary pig, or "short pig", is OK nutrition.
Disturbingly, the fact remains that protein is best when nearest our own, but religious leaders, politicians, and relatives are against what this implies. Long pig is nutritionally ideal, however stick to the shorter variety. Next time you're stranded on a desert island with a small group of people, and you're tempted to change your ethical stance, ask your priest or lawyer first. Fish is good.