Food is any substance consumed to provide nutritional support for the body. Food is a of plant or animal origin, and contains important nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingested by an organism and consumed by the organism's cells in order to produce energy, maintain life, or stimulate growth. Earlier, people maintained food through two methods: hunting and gathering, and agriculture. Today, most of the food energy consumed by the world population is supplied by the food industry.
All 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. 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. Other foods not from animal or plant sources include various edible fungi, especially mushrooms. Fungi and bacteria are used in the preparation of fermented and pickled foods like leavened bread, alcoholic drinks, cheese, pickles, and yogurt.
Many cultures have a recognizable cuisine, a specific set of cooking traditions using various spices or a combination of flavors unique to that culture, which evolves over time. Other differences include preferences(hot or cold, spicy, etc.) and practices, which is known as gastronomy. Many cultures have diversified their foods by means of preparation, cooking methods, and manufacturing. This also includes a complex food trade which helps the cultures to economically survive by way of food, not just by consumption. Some popular types of ethnic foods include Italian, French, Japanese, Chinese, American, Cajun, Thai, and Indian cuisine.
Pleasing and eye-appealing food presentations can encourage people to consume foods. A common saying is people "eat with their eyes". Food presented in a clean and appetizing way will encourage a good flavor, even if unsatisfactory. Texture plays a important role in the enjoyment of eating foods. Contrasts in textures, such as something crunchy in an otherwise smooth dish, may increase the appeal of eating it. Common examples include adding granola to yogurt, adding croutons to a salad or soup, and toasting bread to enhance its crunchiness for a smooth topping, such as jam or butter.
Restaurants employ trained chefs who prepare food, and trained waitstaff to serve the customers. The term restaurant is from the French, as it relates to the restorative nature of the bouillons that were once served in them. In 2005, the population of the United States spent $496 billion for out-of-home dining. Expenditures by type of out-of-home dining were as follows: 40% in full-service restaurants, 37.2% in limited service restaurants (fast food), 6.6% in schools or colleges, 5.4% in bars and vending machines, 4.7% in hotels and motels, 4.0% in recreational places, and 2.2% in others, which includes military bases.