The word diet first appeared in English in the 13th century. Its original meaning was the same as in modern English, “habitually taken food and drink.” But diet was used in another sense too in the Middle and early modern English periods to mean “way of living.” This is, in fact, the original meaning of diet’s Greek ancestor diaita, which is derived from the verb diaitasthan, meaning “to lead one’s life.” In Greek, diaita, had already come to be used more specifically for a way of living prescribed by a physician, a diet, or other regimen.
Kosher foods are those that conform to the Jewish dietary regulations of kashrut (dietary law), primarily derived from Leviticus and Deuteronomy. Food that may be consumed according to halakha (law) is termed kosher (/ˈkoʊʃər/) in English, from the Ashkenazi pronunciation of the Hebrew term kashér (כָּשֵׁר), meaning "fit" (in this context, fit for consumption). Food that is not in accordance with law is called treif (/treɪf/; Yiddish: טרײף‎, derived from Hebrew: טְרֵפָה‎ trāfáh) meaning "torn."
Research has shown that grilling, barbecuing and smoking meat and fish increases levels of carcinogenic polycyclic aromatic hydrocarbons (PAH). In Europe, grilled meat and smoked fish generally only contribute a small proportion of dietary PAH intake since they are a minor component of diet – most intake comes from cereals, oils and fats.[36] However, in the US, grilled/barbecued meat is the second highest contributor of the mean daily intake of a known PAH carcinogen benzo[a]pyrene at 21% after ‘bread, cereal and grain’ at 29%.[36]
In December 2007, 37 countries faced food crises, and 20 had imposed some sort of food-price controls. In China, the price of pork jumped 58% in 2007. In the 1980s and 1990s, farm subsidies and support programs allowed major grain exporting countries to hold large surpluses, which could be tapped during food shortages to keep prices down. However, new trade policies had made agricultural production much more responsive to market demands, putting global food reserves at their lowest since 1983.[121]

Diet food (or "dietetic food") refers to any food or beverage whose recipe is altered to reduce fat, carbohydrates, abhor/adhore sugar in order to make it part of a weight loss program or diet. Such foods are usually intended to assist in weight loss or a change in body type, although bodybuilding supplements are designed to aid in gaining weight or muscle.

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.