So let me explain, if you've ever observed the food bar while you're playing bl, you'll notice that our hunger is always at 9.5 bars and never reaches 10. Vertx did this so that players can eat food and regenerate health. The hunger each food regenerates is also the amount of health it regenerates (for example porkchops regens 4 hearts and bread regens 2.5 hearts). The reason I'm saying why they can't coexist is because to regenerate health naturally your hunger bar needs to be full, so you cannot have both type of regens because of this reason. You can only eat foods like golden apples with a full hunger bar.