In order to digest food, the human body requires

Answer: Enzymes.

Explanation:

In order to digest food the human body needs enzyme. The enzyme lowers down the threshold energy. The energy that is required to convert the substrate into product.

Every substances of the body is digested by the particular enzymes only. So enzymes are necessary for the digestion of the food and obtain energy from them.

food, enzymes, a digestive system you could keep naming (are there any answer options?)