I have notice this ingame for awhile (I remember moment like this back when the game is still in early access). Checking the wiki page about food value, it looks like something is wrong about cooked fish food value? Is this intended?
Edit:
1 monster meat + 1 meat + 2 cooked fish= meatball.
So I guess the issue is cooked fish is missing the 0.5 meat value.
Steps to Reproduce
just watch my video
just watch my video