I know that's all true, I just felt guilty that I was starving my 2 boys lol. It's good that Artie seems to like the new food.
One of mine looks like a Maine coon and is a tall lanky cat, and they're both thin. The other just got diagnosed with allergies to everything, food, environmental, and the only dry food I can find so far is an indoor weight control, which neither if them like or need. Vet wants him on prescription food but he's so picky. My dog with ibd is skinny and won't eat any of the prescription foods so I have to feed him regular food and give him medications but he gets diarrhea and not usually constipation. But he has days where he won't eat much at all. So I can empathize although Artie is farther along and older and has been through much more.