Anytime my 15 year old cat gets particularly hungry he will find a plastic bag if one is available, plastic magazine wrapper, or similar, and eat some of it if he can bite some off. He has always done this.
He doesnt pretend to be hungry unless he is, so last few years we have just made sure to feed him when he shows the signs. Seems to mostly head off the plastic eating, and is a lot easier than making sure there is no plastic around. That turns out to be harder than you would think.