Answer: Fats
Step-by-step explanation:
The food energy can be defined as the chemical energy that animals or humans receive from the food they eat via cellular respiration. The food energy is in the form of biological fuel which are necessary for metabolic processes in the body like respiration, cell growth and repair, reproduction, digestion and other functions.
The food consists of biomolecules like proteins, carbohydrates, fats and others which act as biological fuels.
The fat is a biological fuel which contains the highest amount of food energy per gram. The fat contains 37kcal/g energy. Proteins and carbohydrates only provide 17kcal/g energy.
The fats are stored in the adipocytes of the humans and animals and are the energy reservoirs.