Cannibals are the ultimate drama queens. Forget vegans, the lactose intolerant, those who remain vigilant against gluten: No one has to worry more than a cannibal about where the next meal is coming from. Beyond that, cannibal love poses additional problems. How to broach the subject of this dietary proclivity with someone you’re attracted to? Or is it better to associate only with your kind, to break bread—or whatever—only with those wholly in tune with your needs and impulses?

Luca Guadagnino’s Bones and All, playing at the 79th Venice Film Festival, pleads sympathy for those who crave human flesh: in the movie’s universe, they’re tragic figures, a little like vampires but not nearly as sexy, people who didn’t ask to be born wit…