Étel

tl;dr: étel.

From formal to slang:

• táplálék: most fancy, "nourishment";
• élelem: more official, I think the base of this is used in the word élelmiszer, which is something like "foodstuff"; you may see this word on store signs, etc;
• étel: "food", this is the most common;
• ennivaló: "something to eat";
• kaya: slang;