Confuzzled

[Image from Pixabay] As His Plumpness gets on in years [we're talking Humphrey here] the need has arisen to switch his dry cat food over to something more becoming to his stage in life and one which will continue to contain his girth. Now choosing a new food would be one of the easier tasks life throws at me I thought....how wrong was I?!! Firstly you need to be aware if they're a special breed apparently. I can vouch he is definitely not a Maine Coon so that was relatively straightforward. Any ongoing health problems eg renal...as far as I know he's currently fit as a flea. So that's another whole load of options knocked out. Age....kind of middle aged. They don't do one for that, but using common sense he's certainly not a kitten, but not a veteran either so am guessing one for about a seven year old should do the trick [he was a rescue so all we have to go on is educated guesswork]. Then it started to get complicated....is he an active cat?....well d