Older cat, heathy but thinner

First off, My Ozzy has been blessed with pretty good health. He gets regular checkups and blood work. He was diagnosed with arthritis in his elbow, but his glucos works wonders.
He is 14, give or take a bit.

But he is noticeably thinner than he was the beginning of last year. The vets aren't concerned, but the vets around here have little to offer when it comes to cat nutrition.

I was wondering if Ozzys (or any cats) nutrition needs have maybe shifted since he is getting up there in age?
More fat? Maybe extra vitamins or mineral needs?

Any input or advice for "senior" kitty care would be very appreciated.

I feed Natures Variety Instinct wet and freeze dried by the way. He eats as much as he wants at the moment. 2 secedualed feedings with the freeze dried snacks.

Hi, and welcome to TCS

What you're currently feeding sounds great to me

Has Ozzy's activity changed in the last year? One thing that comes to mind is muscle loss from moving less. I'm seeing that in my 13 year old greyhound at the moment.

Has Ozzy's appetite changed at all? The most obvious cause of weight loss is eating less. If that's the case, then he might to better with more, smaller meals than two bigger ones. Toppers can also help tempt cats to get stuck in. Crumbled freeze dried raw can work well. Other options are crumbled Purebites, bonito flakes, finely grated Parmesan - think strong tasting and stinky

Has Ozzy had a dental recently. Very often, a sore mouth can trigger weight loss. If it hurts to eat, he'll obviously eat less.

I don't recommend upping the fat intake specifically - too much fat can cause diarrhoea, and that's the last thing you want.

Thank you!
He was never much for activities even as a young lad. He did slow down a bit after his arthritis started acting up last year and never fully got on track again. So that could easily be the issue... During the warmer months he enjoys running around outside on his harness, we will have to do more of that when spring comes.

He eats very well! Loves all his food. The freeze dried raw treats are a huge hit with all my fuzzbuckets. He also just got his yearly teeth cleaning/check up a couple months ago, all was good there.

If you can find anything that is made for kittens that suits you, that is higher in vitamins and calories. It will put weight on fairly quickly. My almost 15 year old is eating a lot less, tests fine, and I'm having trouble getting him to eat anything. He loved the kitten food for a while, but is even picking at that lately.  All the luck, and if you find anything that works, please post back!