In extremis, yes. Cats will eat their kittens if they cannot raise them, so severe famine or serious danger from which they cannot escape can trigger this behaviour. It isn't normal or common but it isn't unknown either. One pouch of food a day for a lactating queen is underfeeding serious enough to trigger this response. More likely, of course, assuming he lets the cat out, is that she will be so very thin that she will immediately be taken in by someone, leaving the kittens without a mother.

In any event this man, unless he simply has a very unpleasant sense of humour, is a total idiot.

liz