There are more than a few food sources in Minecraft. Almost all animals drop meat that can be cooked (or eaten raw in a pinch). Growing crops like carrots, beetroot, potatoes and wheat is a big part of the game. All of them can be used in different ways to satisfy hunger.
Some of the best food sources, like cake or mushroom stew, require a bit of work to get, but they’re more than worth it.
Two other food items that require a bit of work and can be considered moderately “expensive” are glistering melons and golden carrots. Both require golden nuggets, which are fairly valuable items to be put into food.