Let's just put it this way, we're both in a plane crash and we're the only two survivors, after we eat every other corpse, which of us gets to eat the other one.
Well, I would imagine that the healthier of the two of us would eat the weaker one.
Let's say I broke my ribs and was unable to truly defend myself in a fistfight. Would you try to stay alive with me by feeding me small portions of yourself, perhaps your fingers or toes?