Staple food

Astaple food,food staple, or simplystaple, is afoodthat is eaten often and in such quantities that it constitutes a dominant portion of a standarddietfor an individual or a population group, supplying a large fraction ofenergy needsand generally forming a significant proportion of the intake of othernutrientsas well.Forhumans, a staple food of a specificsocietymay be eaten as often as every day or every meal, and most people live on a diet based on just a small variety of food staples.Specific staples vary from place to place, but typically are inexpensive or readily available foods that supply one or more of themacronutrientsandmicronutrientsneeded for survival and health:carbohydrates,proteins,fats,minerals, andvitamins.Typical examples includegrains(cerealsandlegumes),seeds,nutsandroot vegetables(tubersandroots). Among them,cereals(rice,wheat,oat,maize, etc.),legumes(lentilsandbeans) andtubers(e.g.potato,taroandyam) account for about 90% of the world's food calorie intake.
Earlyagriculturalcivilizationsvalued thecropfoods that they established as staples because, in addition to providing necessarynutrition, they generally are suitable for storage over long periods of time without decay. Suchnonperishable foodsare the only possible staples during seasons of shortage, such asdry seasonsor coldtemperatewinters, against which times harvests have been stored. During seasons of surplus, wider choices of foods may be available.
Staple foods are derived from eitherplantoranimal productsthat are digestible by humans and can be supplied in substantial quantities. Common plant-based staples includecereals(e.g.rice,wheat,maize,millet,barley,oats,rye,spelt,emmer,triticaleandsorghum),starchytubers(e.g.potato,sweet potato,yamandtaro) orroot vegetables(e.g.cassava,turnip,carrot,rutabagas), and driedlegumes(lentilsandbeans).Animal-based staples include various types ofmeat(typicallylivestockandpoultry),fish,eggs,milkanddairy products(e.g.cheese).Other staple foods includesago(derived from thepithof the sagopalm tree),and large, fleshyfruits(e.g.breadfruit,breadnut,coconutandplantains). Staple foods may also includeprocessed food products(depending on the region) such asolive oil,coconut oil, andsugar.
Generally, staple foods are those eaten  in bulk that supplyenergyto humans, predominantly in the form ofsugarsandcarbohydrates, and so are mainly plant-based, asmeatsandeggsare predominantlyproteinandfat, thoughdairy productsprovide all these. However, not all places are suitable foragriculture, and sopastoralismcan be favoured instead, as it has the advantage that animals can live off of land unsuitable foragricultural cropsand consume the local plant matter that is otherwise inedible to humans and convert that into foods -meat,offal,fat,eggsandmilk- that humans can eat. Animals can therefore provide staples to human diets in inhospitableecosystemssuch asdeserts,steppe,taiga,tundra, andmountainous terrains. Specific examples includeherdingin regions such asMongoliawheresheepare herded, thePrairieswhere theSiouxherdedbison, and theArctic, where theSami peopleherdreindeer.
The dominant staple foods in different parts of the world are a function of weather patterns, local terrain, farming constraints, acquired tastes andecosystems. For example, the main energy source staples in the average African diet are cereals (46 percent), roots and tubers (20 percent) and animal products (7 percent). In Western Europe the main staples in the average diet are animal products (33 percent), cereals (26 percent), and roots and tubers (4 percent).
Most of the human population lives on a diet based on one or more of the following staples: cereals (rice,wheat,maize(corn),millet, andsorghum), roots and tubers (potatoes,cassava,yamsandtaro), and animal products such as meat, milk, eggs, cheese and fish. Regional staples include the plantsrye,soybeans,barley,oats, andteff.
Just 15 plantcropsprovide 90 percent of the world'sfood energyintake (exclusive of meat), withrice,maize, andwheatcomprising 2/3 of human food consumption. These three are the staples of about 80 percent of the world population,and rice feeds almost half of humanity.
Roots and tubers, meanwhile, are important staples for over one billion people in thedeveloping world, accounting for roughly 40 percent of the food eaten by half the population ofsub-Saharan Africa.  Roots and tubers are high incarbohydrates,calcium, andvitamin C, but low inprotein.Cassava root, for example, is a major food staple in the developing world, a basic food source for around 500 million people.
With economic development and free trade, many countries have shifted away from low-nutrient-densitystaple foods to higher-nutrient-density staples, as well as towards greatermeat consumption.
Some foods likequinoa—apseudocereal grainthat originally came from theAndes—were also staples centuries ago.Ocatubers,ullukutubers andgrain amaranthare other foods that may have been historical Andean staples.Pemmicanmade from dried meat and fat was a staple of thePlains Indians of North America.
Most staple foods are currently produced using modern,conventional farmingpractices. However, the production of staple food usingorganic farmingmethods is growing.
Rice is most commonly cooked and eaten as separate entire grains, but most other staple cereals are milled into aflouror meal that can be used to makebread,noodles,pasta,porridgeandmusheslikemealie pap(although both can be eaten either as grains or ground into flour). Root vegetables can be mashed and used to makeporridge-like dishes such aspoiandfufu.Pulses(such aschickpeas, from whichgram flouris made) and starchy root vegetables (such ascannarhizomes) can also be made into flour.
Consumed in isolation, staple foods do not provide the full range ofessential nutrients. The nutrient-deficiency diseasepellagrais associated with a diet consisting primarily ofmaize, while the diseaseberiberiis associated with a diet of refinedwhite rice.Scurvycan result from a lack ofvitamin C, also known as ascorbic acid. One author indicated that the nutritional value of some staple foods are negatively affected by higher levels ofcarbon dioxide, as occurs inclimate change.
The following table shows the nutrient content of 10 major staple vegetable foods in raw form on adry weight basisto account for their different water contents. Raw grains are not edible and cannot be digested, so they must be cooked, sprouted, or otherwise prepared for human consumption. In sprouted and cooked form, the relative nutritional and anti-nutritional contents of each of these grains are different from that of the raw form of these grains, as shown. Potatoes also must be cooked, but should not be sprouted. The highlighted values show the highest nutrient density among these 10 staples. Other foods, consumed in smaller quantities, may have nutrient densities different from these values.