Food is needed by the human body for energy, to repair and build cells and to prevent sickness and heal from it. While it is possible to obtain nutrients in a scientifically controlled manner, common food is the most efficient way of obtaining energy and nutrients.
Food can be divided into energy content and nutrients. The breakdown of fats, proteins and carbohydrates will determine how much energy the body can derive from a given amount of food. Fats and carbohydrates are mainly used for energy, while protein is broken down into amino acids to be used in building and repairing cells and tissues. The nutrients of a food include all the vitamins and minerals that the body needs to stay healthy against sickness.