Well, not usually no, at least not on a grand scale. There are things that can happen to tip the balance, but it has to be on a cataclysmic scale. Such things are called Umbral Cataclysms, but usually there is some sort of signal something is about to happen. For a long while, there was thought there could only be six of them, one for each element, but the Seventh happened five ears ago.

[There seems to be more to it than that, but that's what he says, probably to avoid giving too much of an infodump.]

But when a person eats, he or she takes nutrients from the aether in food. As a person needs to replenish their aether, not eating could lead to severe sickness beyond hunger.