Food is any substance, composed of carbohydrates, water, fats and/or proteins, that is either eaten or drunk by any animal, including humans, for nutrition or pleasure. Items considered food may be sourced from plants, animals or another kingdom such as fungus. Although many human cultures sought food items through hunting and gathering, today most cultures use farming, ranching, and fishing, with hunting, foraging and other methods of a local nature included but playing a minor role.
Many traditions have a recognizable cuisine, a specific set of cooking traditions using various spices or combinations of flavors unique to that culture. Other differences include preferences (hot or cold, spicy etc), and practices, the study of 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, Thai and Indian. Various cultures throughout the world study the dietary analysis of food habits. While evolutionarily speaking, as opposed to culturally, humans are omnivores, religion and social constructs such as morality, activism or environmentalism will often affect which foods they will consume. Food is eaten and typically enjoyed through the sense of taste, the perception of flavor from eating and drinking. Certain tastes are more enjoyable for evolutionary purposes while others are not.
In popular culture, the production of mass food production, specifically meats such as chicken and beef, has come under fire from various documentaries documenting the mass slaughter and poor treatment of animals, most recently Food, Inc, often for easier revenues from large corporations. Along with a current trend towards environmentalism, people in Western culture have had an increasing trend towards consumerism which is the use of herbal supplements, foods for a specific group of person (such as dieters, women or athletes), the use of functional foods (fortified foods, such as omega-3 eggs), and a more ethnically diverse diet.
Foods that spoil easily, such as meats, dairy and seafood, must be prepared a certain way as to not contaminate the people for whom they are prepared. As such, the general rule of thumb is that cold foods (such as dairy products) should be kept cold and hot foods (such as soup) should be kept hot until storage. Cold meats, such as chicken, that are to be cooked should not be placed at room temperature for thawing, at the risk of dangerous bacterial growth, such as salmonella or E. coli.