Okay, but you can't expect anyone else to follow your suit. I hereby declare cannibalism to mean eating any living thing!
They can't change it, either. It takes all/most of society to do that, and it hasn't.
Thank God I usually consume my food conveniently pre-killed! I am still a parangon of virtue !
Wanted to separate this one out in particular...
Bodily Autonomy.
Very basic principle: Your body belongs to you even when you die. That's why people have, famously, had elaborate rituals for the dead. Preparing bodies for the afterlife, interring them for safekeeping underground or in caverns, preserving the body in pyramids, the shell left behind, for the person who can't do it themself.
You make good points, but isn't this the other way round? With the first signs of religion being about explaining death and creating belief of survival of the soul, defiling the body meant depriving of "proper care" and therefore causing harm to the person beyond killing them, hence the moral prohibition, linked to the prohibition of not doing harm. If this belief is taken out of the equation, the taboo is much lessened. You mention organ donor having to declare they are OK to donate and not the hospital taking organs, but precisely, this was reversed (right to oppose on basis of individual belief with consent assumed) as the idea of survival of the self became less widespread, while it might still be as you say in more religious countries. If you take defiling as a way to prevent the soul to go where it must go, either because you don't generally believe in souls or, as it would be the case with fantasy worlds, performing rites has no bearing on what happens (AFAIK, in the FR, your soul is sorted by Kelemvor irrespective of the burial rites, and it's the same in Eberron, everyone goes to Dolurrh and decay there)... and with magic you can ascertain what happened by divining or communing with the gods themselves, there might not be such an emphasis on burial rites (and therefore no harm made to the person if eaten, and no fear/want of eating its spirit). The taboo might come from profundly ingrained religious belief that you somehow harm someone by eating its corpse.
Tangentially, anyone else creeped out by the sheer number of sapient you can harvest for components.
"I defeated the local warlord (a dragon) and as a trophy I am now wearing his skin. I am certainly the good guy here."
A PC once yelled at a dragon "I am wearing your sister. Soon, you'll be my boots." He didn't pretend to be a good guy, so it somehow was appropriately scary.
I have to know: do your human characters eat elves?
Nope, of course! You can eschew something without moral imperative. On the other hand, my lizardfolk characters would if the opportunity arose (which means not killing innocent for meat, obviously) (though I guess they'd prefer dwarf meat, elves seem too lean for meat).
