A staple food, food staple, or simply a staple, is a food that is eaten routinely and in such quantities that it constitutes a dominant portion of a standard diet for a given people, supplying a large fraction of energy needs and generally forming a significant proportion of the intake of other nutrients as well. A staple food of a specific society may be eaten as often as every day or every meal, and most people live on a diet based on just a small number of food staples. Specific staples vary from place to place, but typically are inexpensive or readily available foods that supply one or more of the macronutrients needed for survival and health: carbohydrates, proteins, and fats. Typical examples include tubers and roots, grains, legumes, and seeds.
Staple foods are derived either from vegetables or animal products, and common staples include cereals (such as rice, wheat, maize, millet, and sorghum), starchy tubers or root vegetables (such as potatoes, cassava, sweet potatoes, yams, or taro), meat, fish, eggs, milk, and cheese. Other staple foods include pulses (dried legumes), sago (derived from the pith of the sago palm tree), and fruits (such as breadfruit and plantains). Staple foods may also include (depending on the region): olive oil, coconut oil and sugar (e.g. from plantains).
Most of the human population lives on a diet based on one or more of the following staples: cereals (rice, wheat, maize (corn), millet, and sorghum), roots and tubers (potatoes, cassava, yams and taro), and animal products such as meat, milk, eggs, cheese and fish. Regional staples include the plants rye, soybeans, barley, oats, and teff.
Roots and tubers, meanwhile, are important staples for over one billion people in the developing world, accounting for roughly 40 percent of the food eaten by half the population of sub-Saharan Africa. Roots and tubers are high in carbohydrates, calcium, and vitamin C, but low in protein. Cassava root, for example, is a major food staple in the developing world, a basic food source for around 500 million people.
Rice is most commonly cooked and eaten as separate entire grains, but most other staple cereals are milled into a flour or meal that can be used to make bread, noodles, pasta, porridge and mushes like mealie pap. Root vegetables can be mashed and used to make porridge-like dishes such as poi and fufu. Pulses (such as chickpeas, from which gram flour is made) and starchy root vegetables (such as canna rhizomes) can also be made into flour.
Plant-based food staples may not provide a full range of nutrients. The nutrient-deficiency disease pellagra is associated with a diet consisting primarily of maize, while the disease beriberi is associated with a diet of refined white rice. Scurvy can result from a lack of vitamin C, also known as ascorbic acid. One author indicated that the nutritional value of some staple foods are negatively impacted by higher levels of carbon dioxide, as occurs in climate change.