Three grains supply most of the world’s cereal energy
Corn, wheat, and rice together make about 87% of all grain grown on Earth. Just over half of global crops feed people directly; the rest go mainly to livestock and biofuels. The plate that looks endlessly varied still rests on a handful of grasses.
Food is whatever an organism ingests for energy and nutrients—carbohydrates, fats, proteins, vitamins, minerals—usually from plants, animals, or fungi. Humans cook most of what they eat and now lean on industrial agriculture and long distribution chains. That system depends heavily on fossil fuels and may account for as much as 37% of greenhouse gas emissions. Agencies from the FAO to the World Food Programme watch safety and security because food webs touch water, biodiversity, economics, and climate.
In ecosystems, photosynthetic producers sit at the base; herbivores, carnivores, omnivores, and decomposers stack above. Humans rank as apex predators and omnivores, drawing on vegetables, meat, dairy, eggs, mushrooms, and seaweed. Cereal grain delivers more food energy worldwide than any other crop type. Plants take carbon, oxygen, and hydrogen from air and water, and nitrogen, phosphorus, and potassium from soil; bacteria fix atmospheric nitrogen into ammonia—though Haber-Bosch industry now makes most of the world’s ammonia. Roughly 75,000 angiosperm species may be edible, with perhaps 7,000 eaten often.
Culinary categories blur botany: tomatoes and peppers are fruits used as vegetables; grains are edible grass seeds; nuts are woody-shelled dry fruits. Fruit can be mostly water and sugar; vegetables skew toward starch, fiber, and folate; nuts pack protein and vitamin E. Animal foods supply complete proteins—about 30 grams in a 4-ounce steak or chicken breast, 7 grams in a large egg, 8 grams in a cup of milk—plus B12 and minerals. Fermenting fungi and bacteria turn staples into bread, wine, cheese, and yogurt. Classification schemes multiply, from four basic groups to FAO/WHO lists of nearly twenty categories, but the energetic core remains those three cereal giants.
Source: Food
