Why would we think that eating something according to the way “nature” “intended” (or, if you prefer, for which we are naturally adapted) would be morally abhorrent?
How does it violate the golden rule? For example, if it could not be avoided, I would hope that someone would eat me if they were starving. I’m hovering over my body, dead, everyone around my dead body is starving, and they’re not eating me? I would be offended!