Thanks for suggesting this. I don't think anyone has mentioned this idea previously & it isn't something I'd considered!
I created the current system from the perspective of 'you, the player, know what you like and how you would feel about the weight gain of your own character'. But as you don't experience the actual sensations of what it is like to get fatter, telling you how it makes you feel would work really well. I like your idea of the feeders being able to mirror the player with the corruption system, too.