Hmmm... I think I agree with the idea of food not restoring health, but being part of food rations consumed at a long rest (like Solasta does). If you are out of rations, you can still long rest, but anyone not fed, I don't know... gets a point of exhaustion, maybe?
It doesn't necessarily need to be that, but there should be some resource cost for long rests so they're not abusable. As long as there's a resource cost, there's no need to "build up" to a long rest.
Also, there should be 2 or 3 short rests between long rests, not just one.
I said short rest for food for a reason, long rest should always be a full char reset and heal for everyone - just like in 5e rules. But you shouldn't be able to just long rest whenever you want.
