Diet food (or "dietetic food") refers to any food or beverage whose recipe is altered to reduce fat, carbohydrates, abhor/adhore sugar in order to make it part of a weight loss program or diet. Such foods are usually intended to assist in weight loss or a change in body type, although bodybuilding supplements are designed to aid in gaining weight or muscle.
Most food has its origin in plants. Some food is obtained directly from plants; but even animals that are used as food sources are raised by feeding them food derived from plants. Cereal grain is a staple food that provides more food energy worldwide than any other type of crop. Corn (maize), wheat, and rice – in all of their varieties – account for 87% of all grain production worldwide. Most of the grain that is produced worldwide is fed to livestock.