They might, but I wouldn't recommend it. What wouldn't be eaten would sink to the bottom, and create a mess of fungus, bacteria, and even a vector for potential disease. At least that's what I think. It would be akin to leaving dead fish in the water IMHO.

And how do you know all the nutrients they need are in it? I would stick with floating feed that is made for fish that you can monitor if it is consumed, and if you're serious about giving your fish a balanced diet.

Would you give dog food to your cat? Did you know if you did you would kill it?

Fish culturists used to give ground liver to fish and meat byproducts before modern day fish pellets came about, and still do on occasion in special circumstances. And I have heard of feeding feed trained largemouths some fatty tallow before they go into winter but I can't tell you if that is a good idea from experience. I do know fish can get too much fat and develop fatty livers. No real need for fatty reserves in summer.

If pigs could fly bacon would be harder to come by and there would be a lot of damaged trees.