Here's a book about cannibalism. Haven't read it myself, so I can't verify whether or not it's a good read, just something that came to mind.
amazon.com/Contingency-Cannibalism-Superhardcore-Survivalisms-Little/dp/1581600259

And here's a reddit post from a guy who ate some of his own foot.
np.reddit.com/r/IAmA/comments/8p5xlj/hi_all_i_am_a_man_who_ate_a_portion_of_his_own/