Define food in terms of science?

Answer 1

Food is anything that nourishes the body to sustain life, provide energy, promote growth, etc. The body uses chemical processes to break down those foods into macronutrients and micronutrients. A macronutrient would be a protein or a carbohydrate, and micronutrients would be an amino acid or glucose (what the macronutrients get broken down into). Those nutrients go through cycles in the body (such as the Krebs cycle) to transform those nutrients into energy in the form of ATP that the body can use.