It's so logical and so simple. Fat is the backup fuel system. The role it plays in the body is that when there's no carbohydrate around, fat will become the primary energy fuel. That's pretty well known. ↗
This world is run with far too tight a rein for luck to interfere. Fortune sells her wares; she never gives them. In some form or other, we pay for her favors; or we go empty away. ↗