Cooking or cookery is the art, technology, science and craft of preparing food for consumption. Cooking techniques and ingredients vary widely across the world, from grilling food over an open fire to using electric stoves, to baking in various types of ovens, reflecting unique environmental, economic, and cultural traditions and trends. The ways or types of cooking also depend on the skill and type of training an individual cook has. Cooking is done both by people in their own dwellings and by professional cooks and chefs in restaurants and other food establishments. Cooking can also occur through chemical reactions without the presence of heat, such as in ceviche, a traditional Latin American dish where fish is cooked with the acids in lemon or lime juice.

Cooking requires applying heat to a food which usually, though not always, chemically changes the molecules, thus changing its flavor, texture, appearance, and nutritional properties.[88] Cooking certain proteins, such as egg whites, meats, and fish, denatures the protein, causing it to firm. There is archaeological evidence of roasted foodstuffs at Homo erectus campsites dating from 420,000 years ago.[89] Boiling as a means of cooking requires a container, and has been practiced at least since the 10th millennium BC with the introduction of pottery.[90]

^ Fraga, Helder; Malheiro, Aureliano C.; Moutinho-Pereira, José; Cardoso, Rita M.; Soares, Pedro M. M.; Cancela, Javier J.; Pinto, Joaquim G.; Santos, João A.; et al. (24 September 2014). "Integrated Analysis of Climate, Soil, Topography and Vegetative Growth in Iberian Viticultural Regions". PLoS ONE. 9 (9): e108078. doi:10.1371/journal.pone.0108078. PMC 4176712. PMID 25251495.
Many cultures hold some food preferences and some food taboos. Dietary choices can also define cultures and play a role in religion. For example, only kosher foods are permitted by Judaism, halal foods by Islam, and in Hinduism beef is restricted.[148] In addition, the dietary choices of different countries or regions have different characteristics. This is highly related to a culture's cuisine.
Peasant foods have been described as being the diet of peasants, that is, tenant or poorer farmers and their farm workers,[53] and by extension, of other cash-poor people. They may use ingredients, such as offal and less-tender cuts of meat, which are not as marketable as a cash crop. Characteristic recipes often consist of hearty one-dish meals, in which chunks of meat and various vegetables are eaten in a savory broth, with bread or other staple food. Sausages are also amenable to varied readily available ingredients, and they themselves tend to contain offal and grains.
The purpose of the Mayo Clinic Diet is to help you lose excess weight and to find a way of eating that you can sustain for a lifetime. It focuses on changing your daily routine by adding and breaking habits that can make a difference in your weight, such as eating more fruits and vegetables, not eating while you watch TV, and moving your body for 30 minutes a day.
Several studies published since 1990 indicate that cooking meat at high temperature creates heterocyclic amines (HCAs), which are thought to increase cancer risk in humans. Researchers at the National Cancer Institute found that human subjects who ate beef rare or medium-rare had less than one third the risk of stomach cancer than those who ate beef medium-well or well-done.[34] While avoiding meat or eating meat raw may be the only ways to avoid HCAs in meat fully, the National Cancer Institute states that cooking meat below 212 °F (100 °C) creates "negligible amounts" of HCAs. Also, microwaving meat before cooking may reduce HCAs by 90% by reducing the time needed for the meat to be cooked at high heat.[34] Nitrosamines are found in some food, and may be produced by some cooking processes from proteins or from nitrites used as food preservatives; cured meat such as bacon has been found to be carcinogenic, with links to colon cancer. Ascorbate, which is added to cured meat, however, reduces nitrosamine formation.[33][35]
Texture plays a crucial 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.[82]
In nutrition, diet is the sum of food consumed by a person or other organism.[1] The word diet often implies the use of specific intake of nutrition for health or weight-management reasons (with the two often being related). Although humans are omnivores, each culture and each person holds some food preferences or some food taboos. This may be due to personal tastes or ethical reasons. Individual dietary choices may be more or less healthy.

Most 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.[2] Corn (maize), wheat, and rice – in all of their varieties – account for 87% of all grain production worldwide.[3][4][5] Most of the grain that is produced worldwide is fed to livestock.