My sixteen year old kitty gets whatever junk food he wants. At the moment, it seems that only the cheapest, stinkiest, pates will do, and even then, we have to rotate the flavours and feed him three times a day. We've a 24/7 Friskies buffet out for the old guy, and we're throwing away at least half of it.
On the plus side, though, the old guy has gained back a bit of weight and the vet has stopped pushing for more expensive tests ("Maybe I missed something on the last round..." "Yes, but if this test comes back positive, will it improve his life in any way?" "No, but at least we'll know!" Yeah, I'm not funding my vet's desire to satisfy her curiosity!)
I imagine his "seafood" pate must contain a bit of Fido, some Bessie, a chunk of Wilbur's butt, and who knows what funky drugs, chemicals and toxins.
I fed him expensive food that we bought from the vet when he was young - low ash, quality ingredients, good for his teeth, etc. Now that he's old, he gets to live on the kitty equivalent of burgers and fries. It reminds me of my mother-in-law's final days, when all she wanted to do was eat chips and ice cream.