Is it okay to say just "food" not "foods"?
Yes, when we refer to consumables (things we eat) that give our bodies nourishment, we usually say "food." However, on some occasions we do use "foods" in the plural form to mean "types of food" (like "foods from around the world"). Ex: Don't order takeout again. There's food in the fridge. Ex: The market sells foods from all over the world, including Italian, French, Japanese, and Indian.