When food means something edible, it is a countable noun, followed by S. Food, which is both countable and uncountable. When Food means "food, food, diet and nutrients", it is an uncountable noun. Food can also be used as a metaphor, meaning "something to think about" and "spiritual food". It is an uncountable noun and is usually used with the preposition for.

Wash your hands thoroughly with hot soapy water before handling any food.

Wash your hands well with hot soapy water before eating.

Shallow sea beds produce abundant food.

Shallow sea bed provides abundant food.

Flavor coffee is available in gourmet shops and coffee shops.

Fancy coffee can be bought in gourmet shops and coffee shops.

Pay special attention to washing hands before touching food.

Don't forget to wash your hands before touching food.

As far as food is concerned, I always have a curious heart.

I have always been very curious about food.