The Old English word for dinner, disner, means to break a fast, and was the first meal eaten in the day until its meaning shifted in the mid-13th century. It was not until the 15th century that “breakfast” came into use in written English to describe a morning meal, which literally means to break the fasting period of the prior night; in Old English the term was morgenmete meaning "morning meal."

Cereal grain crops are grown in greater quantities and provide more food energy worldwide than any other type of crop. In their natural, unprocessed, whole grain form, cereals are a rich source of vitamins, minerals, carbohydrates, fats, oils, and protein. When processed by the removal of the bran, and germ, the remaining endosperm is mostly carbohydrate. In some developing countries, grain in the form of rice, wheat, millet, or maize constitutes a majority of daily sustenance.

Energy bars are supplemental bars containing cereals and other high energy foods targeted at people who require quick energy but do not have time for a meal. Energy bars generally don't contain sugar alcohols, since these bars, due to type of carbohydrate content, don't require low calorie sweeteners to improve their taste. Fats in energy bars are kept to minimum and their main sources are often cocoa butter and dark chocolate.

Protein bars are nutrition bars that contain a high proportion of protein to carbohydrates/fats. There are different kinds of food bars to fill different purposes. Energy bars provide the majority of their food energy (calories) in carbohydrate form. Meal replacement bars are intended to replace the variety of nutrients in a meal.