The reason I bring this up: I feed my cats pumpkin and broccoli. Yes, that makes me ultra weird, and don't I know it. But really, it's for their own good. Eating these fiber-laden veggies means they'll stop with the eating of the plastic. And that's just good all the way around.
But the really weird part is that I had to experiment with pumpkin-to-catfood ratios to get them to eat it. So now I'm buying pumpkin, mixing it with wet catfood and feeding my kitties. Yes, I'm insane.