thumb|400px|Average daily calorie consumption
Food is any substance, usually composed of
carbohydrates,
fats,
proteins and
water, that can be
eaten or
drunk by an animal, including humans, for
nutrition or pleasure. Items considered food may be sourced from
plants,
animals or other categories such as
fungus or fermented products like
alcohol. 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.
Most traditions have a recognizable
cuisine, a specific set of
cooking traditions, preferences, 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.
Many cultures study the dietary analysis of food
habits. While humans are
omnivores, religion and social constructs such as
morality often affect which foods they will consume. Food safety is also a concern with
foodborne illness claiming many lives each year. In many languages, food is often used metaphorically or figuratively, as in "food for thought".
Food sources
Almost all foods are of plant or animal origin. However
water and
salt (both
inorganic substances) are important parts of the human diet. Salt is often eaten as a
flavoring or
preservative.
Other foods not from animal or plant sources include various edible
fungi, such as
mushrooms. Fungi and ambient
bacteria are used in the preparation of
fermented and
pickled foods such as leavened
bread,
alcoholic drinks,
cheese,
pickles, and
yogurt. Many cultures eat
seaweed, a
protist, or
blue-green algae (cyanobacteria) such as
Spirulina. Additionally
baking soda, another inorganic substance, is used in food preparation.
Plants
thumb|Foods from plant sourcesMany
plants or plant parts are eaten as food. There are around 2,000 plant species which are cultivated for food, and many have several distinct
cultivars.
Seeds of plants are a good source of food for animals, including humans because they contain nutrients necessary for the plant's initial growth. In fact, the majority of food consumed by human beings are seed-based foods. Edible seeds include
cereals (such as maize,
wheat, and
rice),
legumes (such as
beans,
peas, and
lentils), and
nuts.
Oilseeds are often pressed to produce rich oils, such as
sunflower,
rapeseed (including
canola oil), and
sesame.
[McGee, Chapter 9.] One of the earliest food
recipes made from ground chickpeas is called
hummus, which can be traced back to
Ancient Egypt times.
Fruits are the ripened ovaries of plants, including the seeds within. Many plants have evolved fruits that are attractive as a food source to animals, so that animals will eat the fruits and excrete the seeds some distance away. Fruits, therefore, make up a significant part of the diets of most cultures. Some botanical fruits, such as
tomatoes,
pumpkins and
eggplants, are eaten as vegetables. (For more information, see
list of fruits.)
Vegetables are a second type of plant matter that is commonly eaten as food. These include
root vegetables (such as
potatoes and
carrots),
leaf vegetables (such as
spinach and
lettuce),
stem vegetables (such as
bamboo shoots and
asparagus), and
inflorescence vegetables (such as
globe artichokes and
broccoli). Many
herbs and
spices are highly-flavorful vegetables.
Animals
thumb|300px|Various raw meats
Animals can be used as food either directly, or indirectly by the products they produce.
Meat is an example of a direct product taken from an animal, which comes from either
muscle systems or from
organs. Food products produced by animals include
milk produced by
mammals, which in many cultures is drunk or processed into
dairy products such as cheese or
butter. In addition birds and other animals lay
eggs, which are often eaten, and
bees produce
honey, a popular sweetener in many cultures. Some cultures
consume blood, some in the form of
blood sausage, as a thickener for sauces, a
cured salted form for times of food scarcity, and others use
blood in stews such as
civet.
Production
thumb|[[Tractor and
Chaser bin]]
Food is traditionally obtained through farming, ranching, and fishing, with
hunting,
foraging and other
methods of subsistence locally important. More recently, there has been a growing trend towards more
sustainable agricultural practices. This approach, which is partly fueled by consumer demand, encourages
biodiversity, local self-reliance and
organic farming methods. Major influences on food production are international organizations, (e.g. the
World Trade Organization and
Common Agricultural Policy), national government policy (or law), and war.
[Messer, 53-91.]Preparation
While some food can be eaten raw, many foods undergo some form of preparation for reasons of safety,
palatability, or
flavor. At the simplest level this may involve washing, cutting, trimming or adding other foods or ingredients, such as spices. It may also involve mixing, heating or cooling,
pressure cooking, fermentation, or combination with other food. In a home, most food preparation takes place in a
kitchen. Some preparation is done to enhance the
taste or aesthetic appeal; other preparation may help to
preserve the food; and others may be involved in cultural identity. A
meal is made up of food which is prepared to be eaten at a specific time and place.
Animal slaughter and butchering
thumb|Workers and cattle in a slaughterhouseThe preparation of animal-based food will usually involve
slaughter,
evisceration, hanging, portioning and
rendering. In developed countries, this is usually done outside the home in
slaughterhouses which are used to process animals en mass for meat production. Many countries regulate their slaughterhouses by law. For example, the
United States has established the Humane Slaughter Act of 1958, which requires that an animal be stunned before killing. This act, like those in many countries, exempts slaughter in accordance to religious law, such as
kosher shechita and dhabiĥa halal. Strict interpretations of
kashrut require the animal to be fully aware when its carotid artery is cut.
On the local level, a butcher may commonly break down larger animal meat into smaller manageable cuts and pre-wrapped for commercial sale or wrapped to order in butcher paper. In addition, fish and
seafood may be fabricated into smaller cuts by a fish monger at the local level. However fish butchery may be done on board a fishing vessel and quick-frozen for preservation of quality.
Cooking
thumb|upright|Cooking with a Wok in China
The term "cooking" encompasses a vast range of methods, tools and combinations of ingredients to improve the flavor or digestibility of food. Cooking technique, known as
culinary art, generally requires the selection, measurement and combining of ingredients in an ordered procedure in an effort to achieve the desired result. Constraints on success include the variability of ingredients, ambient conditions,
tools, and the skill of the individual cooking. The diversity of cooking worldwide is a reflection of the myriad nutritional, aesthetic, agricultural, economic, cultural and religious considerations that impact upon it.
[Mead, 11-19.]Cooking requires applying heat to a food which usually, though not always, chemically transforms it, thus changing its flavor,
texture, appearance, and nutritional properties. There is archaeological evidence of roasted foodstuffs at
Homo erectus campsites dating from 420,000 years ago. Boiling as a means of cooking requires a container, and was practiced at least since the 10th millennium BC with the introduction of
pottery.
Cooking equipment and methods
There are many types of cooking equipment used for cooking.
Ovens are one type of cooking equipment which can be used for baking or roasting and offer a dry-heat cooking method. Different cuisines will use different types of ovens, for example Indian culture uses a
Tandoor oven is a cylindrical clay oven which operates at a single high temperature, while western kitchens will use variable temperature
convection ovens, conventional ovens,
toaster ovens in addition to non-radiant heat ovens like the
microwave oven. Ovens may be wood-fired, coal-fired, gas, electric, or oil-fired.
thumb|A [[stainless steel frying pan]]
Various types of cook-tops are used as well. They carry the same variations of fuel types as the ovens mentioned above. cook-tops are used to heat vessels placed on top of the heat source, such as a
sauté pan, sauce pot,
frying pan,
pressure cooker, etc. These pieces of equipment can use either a moist or dry cooking method and include methods such as
steaming,
simmering,
boiling, and
poaching for moist methods; while the dry methods include
sautéing,
pan frying, or
deep-frying.
thumb|Traditional asadoIn addition, many cultures use grills for cooking. A
grill operates with a radiant heat source from below, usually covered with a metal grid and sometimes a cover. An open bit barbecue in the American south is one example along with the American style outdoor grill fueled by wood, liquid propane or charcoal along with soaked wood chips for smoking. A
Mexican style of barbecue is called
barbacoa, which involves the cooking of meats and whole sheep over open fire. In
Argentina,
asado is prepared on a grill held over an open pit or fire made upon the ground, on which a whole animal is grilled or in other cases smaller cuts of the animal.
Raw food
thumb|Many types of sushi ready to be eaten
Certain cultures highlight animal and vegetable foods in their raw state.
Salads consisting of raw vegetables or fruits are common in many cuisines.
Sashimi in
Japanese cuisine consists of raw sliced
fish or other meat, and
sushi often incorporates raw fish or other seafood as well.
Steak tartare and salmon tartare are dishes made from diced or ground raw beef or salmon respectively, mixed with various ingredients and served with
baguette,
brioche or
frites. In Italy,
carpaccio is a dish of very thin sliced raw
beef, drizzled with a
vinaigrette made with olive oil. A popular health food movement known as
raw foodism promotes a mostly
vegan diet of raw fruits, vegetables and grains prepared in various ways, including juicing, food dehydration, sprouting, and other methods of preparation that do not heat the food above 118 degrees Fahrenheit.
Restaurants
188px|thumb|right| McDonald's Restaurant Riyadhthumb|[[Tom's Restaurant (Manhattan)|Tom's Restaurant, a restaurant in
New York]]
Many cultures produce food for sale in restaurants for paying customers. These restaurants often have trained
chefs who prepare the food, while trained waitstaff serve the customers. The term
restaurant is credited to the
French from the 19th century, as it relates to the restorative nature of the
bouillons that were once served in them. However, the concept pre-dates the naming of these establishments, as evidence suggests commercial food preparation may have existed during the age of the city of
Pompeii, as well as an urban sales of prepared foods in
China during the
Song Dynasty. The
coffee shops or
cafes of 17th century
Europe may also be considered an early version of the restaurant. In 2005 the United States spent $496 billion annually for out-of-home dining. Expenditures by type of out-of-home dining was 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 other which includes military bases.
Food manufacture
thumb|Packaged household food itemsPackaged foods are manufactured outside the home for purchase. This can be as simple as a
butcher preparing meat, or as complex as a modern international
food industry. Early food processing techniques were limited by available food preservation, packaging and transportation. This mainly involved
salting,
curing, curdling,
drying,
pickling,
fermentation and
smoking. Food manufacturing arose during the
industrial revolution in the 19th century. This development took advantage of new
mass markets and emerging new technology, such as
milling, preservation,
packaging and
labeling and transportation. It brought the advantages of pre-prepared time saving food to the bulk of ordinary people who did not employ domestic servants.
[Jango-Cohen]At the start of the 21st century, a two-tier structure has arisen, with a few international food processing giants controlling a wide range of well-known food
brands. There also exists a wide array of small local or national food processing companies. Advanced technologies have also come to change food manufacture. Computer-based control systems, sophisticated
processing and packaging methods, and
logistics and
distribution advances, can enhance product quality, improve
food safety, and reduce costs.
Commercial trade
International exports and imports
thumb|300px|Food imports in 2005
The
World Bank reported that the European Union was the top food importer in 2005, followed at a distance by the USA and Japan. Food is now traded and marketed on a global basis. The variety and availability of food is no longer restricted by the diversity of locally grown food or the limitations of the local growing season. Between 1961 and 1999, there has been a 400% increase in worldwide food exports. Some countries are now economically dependent on food exports, which in some cases account for over 80% of all exports.
In 1994, over 100 countries became signatories to the
Uruguay Round of the
General Agreement on Tariffs and Trade in a dramatic increase in
trade liberalization. This included an agreement to reduce subsidies paid to farmers, underpinned by the
WTO enforcement of
agricultural subsidy,
tariffs, import
quotas and settlement of trade disputes that cannot be bilaterally resolved. Where trade barriers are raised on the disputed grounds of public health and safety, the WTO refer the dispute to the
Codex Alimentarius Commission, which was founded in 1962 by the
United Nations Food and Agriculture Organization and the World Health Organization. Trade liberalization has greatly affected world food trade.
Marketing and retailing
thumb|Packaged food aisles of supermarket in [[Portland, Oregon,
United States of America.]]
Food marketing brings together the producer and the consumer. It is the chain of activities that brings food from "farm gate to plate." The marketing of even a single food product can be a complicated process involving many producers and companies. For example, fifty-six companies are involved in making one
can of chicken noodle soup. These businesses include not only chicken and vegetable processors but also the companies that transport the ingredients and those who print labels and manufacture cans. The food marketing system is the largest direct and indirect non-government employer in the United States.
In the pre-modern era, the sale of surplus food took place once a week when farmers took their wares on market day, into the local village marketplace. Here food was sold to
grocers for sale in their local shops for purchase by local consumers.
With the onset of industrialization, and the development of the food processing industry, a wider range of food could be sold and distributed in distant locations. Typically early grocery shops would be
counter-based shops, in which purchasers told the shop-keeper what they wanted, so that the shop-keeper could get it for them.
In the 20th century
supermarkets were born. Supermarkets brought with them a
self service approach to shopping using
shopping carts, and were able to offer quality food at lower cost through
economies of scale and reduced staffing costs. In the latter part of the 20th century, this has been further revolutionized by the development of vast warehouse-sized, out-of-town supermarkets, selling a wide range of food from around the world.
Unlike food processors, food retailing is a two-tier market in which a small number of very large
companies control a large proportion of supermarkets. The supermarket giants wield great purchasing power over farmers and processors, and strong influence over consumers. Nevertheless, less than ten percent of consumer spending on food goes to farmers, with larger percentages going to
advertising, transportation, and intermediate corporations.
Prices
Consumers worldwide faced rising food prices, it was reported on March 24, 2008. Reasons for this development are freak weather, dramatic changes in the
global economy, including higher
oil prices, lower food reserves and growing consumer demand in
China and
India. In the long term, prices are expected to stabilize. Farmers will grow more grain for both
fuel and food and eventually bring prices down. Already this is happening with
wheat, with more
crops to be planted in the
United States,
Canada and
Europe in 2009. However, the
Food and Agriculture Organization projects that consumers still face at least until 2018 more expensive food. It is rare that the spikes are hitting all major foods in most countries at once. Food prices rose 4 percent in the United States 2007, the highest rise since 1990, and are expected to climb as much again 2008. As of December 2007, 37 countries faced food crises, and 20 had imposed some sort of food-price controls. In China, the price of
pork has jumped 58 percent in 2007. In the 1990s and 1980s, 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. But new trade policies have made agricultural production much more responsive to market demands—putting global food reserves at their lowest since 1983.
Food prices are rising, wealthier Asian consumers are westernizing their diets, and farmers and nations of the third world are struggling to keep up the pace. The past five years have seen rapid growth in the contribution of Asian nations to the Global Fluid and Powdered Milk Manufacturing industry, which in 2008 accounts for more than 30% of production, while China alone accounts for more than 10% of both production and consumption in the Global Fruit and Vegetable Processing and Preserving industry. The trend is similarly evident in industries such as Soft Drink and Bottled Water Manufacturing, as well as Global Cocoa, Chocolate and sugar Confectionery Manufacturing, forecast to grow by 5.7% and 10.0% respectively during 2008 in response to soaring demand in China and Southeast Asian markets.
Famine and hunger
180px|thumb|[[Italy|Italian €2 commemorative coin of 2004 celebrating the World Food Programme]]
Food deprivation leads to malnutrition and ultimately
starvation. This is often connected with
famine, which involves the absence of food in entire communities. This can have a devastating and widespread effect on human health and mortality.
Rationing is sometimes used to distribute food in times of shortage, most notably during times of war.
Starvation is a significant international problem. Approximately 815 million people are undernourished, and over 16,000 children die per day from hunger-related causes. Food deprivation is regarded as a deficit need in
Maslow's hierarchy of needs and is measured using
famine scales.
Food aid
Food aid can benefit people suffering from a shortage of food. It can be used to improve peoples' lives in the short term, so that a society can increase its standard of living to the point that food aid is no longer required. Conversely, badly managed food aid can create problems by disrupting local markets, depressing crop prices, and discouraging food production. Sometimes a cycle of food aid dependence can develop. Its provision, or threatened withdrawal, is sometimes used as a political tool to influence the policies of the destination country, a strategy known as
food politics. Sometimes, food aid provisions will require certain types of food be purchased from certain sellers, and food aid can be misused to enhance the markets of donor countries. International efforts to distribute food to the neediest countries are often co-ordinated by the
World Food Programme.
Safety
thumbnail|right|[[Salmonella bacteria is a common cause of foodborne illness, particularly in undercooked
chicken and
chicken eggs]]
Foodborne illness, commonly called "food poisoning," is caused by
bacteria,
toxins,
viruses,
parasites, and
prions. Roughly 7 million people die of food poisoning each year, with about 10 times as many suffering from a non-fatal version.
[National Institute of Health, MedlinePlus Medical Encyclopedia] The two most common factors leading to cases of bacterial foodborne illness are cross-contamination of ready-to-eat food from other uncooked foods and improper temperature control. Less commonly, acute adverse reactions can also occur if chemical contamination of food occurs, for example from improper storage, or use of non-food grade soaps and disinfectants. Food can also be adulterated by a very wide range of articles (known as 'foreign bodies') during farming, manufacture, cooking, packaging, distribution or sale. These foreign bodies can include pests or their droppings, hairs, cigarette butts, wood chips, and all manner of other contaminants. It is possible for certain types of food to become contaminated if stored or presented in an unsafe container, such as a ceramic pot with lead-based glaze.
thumb|250px|Hazard Analysis and Critical Control Points (HACCP) Flowchart
Food poisoning has been recognized as a disease of man since as early as Hippocrates. The sale of
rancid, contaminated or adulterated food was commonplace until introduction of
hygiene, refrigeration, and vermin controls in the 19th century. Discovery of techniques for killing bacteria using heat and other
microbiological studies by scientists such as
Louis Pasteur contributed to the modern sanitation standards that are ubiquitous in developed nations today. This was further underpinned by the work of
Justus von Liebig, which led to the development of modern
food storage and
food preservation methods. In more recent years, a greater understanding of the causes of food-borne illnesses has led to the development of more systematic approaches such as the
Hazard Analysis and Critical Control Points (
HACCP), which can identify and eliminate many risks.
Allergies
Some people have
allergies or sensitivities to foods which are not problematic to most people. This occurs when a person's
immune system mistakes a certain food protein for a harmful foreign agent and attacks it. About 2% of adults and 8% of children have a food allergy.
[National Institute of Health] The amount of the food substance required to provoke a reaction in a particularly susceptible individual can be quite small. In some instances, traces of food in the air, too minute to be perceived through smell, have been known to provoke lethal reactions in extremely sensitive individuals. Common food allergens are
gluten,
corn,
shellfish (mollusks),
peanuts, and
soy.
Allergens frequently produce symptoms such as
diarrhea,
rashes, bloating,
vomiting, and
regurgitation. The digestive complaints usually develop within half an hour of ingesting the
allergen.
Rarely, food allergies can lead to a
medical emergency, such as
anaphylactic shock,
hypotension (low blood pressure), and loss of consciousness. An allergen associated with this type of reaction is peanut, although
latex products can induce similar reactions.
Initial treatment is with
epinephrine (adrenaline), often carried by known patients in the form of an
Epi-pen or
Twinject.
Diet
thumb|A package of halal-certified frozen food ([[baozi|steamed cabbage buns) from
Jiangsu province, China]]
Cultural and religious diets
Dietary habits are the habitual decisions a person or culture makes when choosing what foods to eat.
[Wansink, Mindless Eating: Why We Eat More Than We Think] Although humans are omnivores, 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, and
halal foods by
Islam, in the diet of believers. In addition, the dietary choices of different countries or regions have different characteristics. This is highly related to a culture's
cuisine.
thumb|Children in this photograph from a [[Nigerian
orphanage show symptoms of
malnutrition, with four illustrating the gray-blond hair symptomatic of
kwashiorkor.]]
Diet deficiencies
Dietary habits play a significant role in the health and mortality of all humans. Imbalances between the consumed fuels and expended energy results in either starvation or excessive reserves of
adipose tissue, known as body fat. Poor intake of various vitamins and minerals can lead to diseases which can have far-reaching effects on health. For instance, 30% of the world's population either has, or is at risk for developing,
Iodine deficiency. It is estimated that at least 3 million children are blind due to
vitamin A deficiency.
Vitamin C deficiency results in
scurvy.
Calcium,
Vitamin D and
phosphorus are inter-related; the consumption of each may affect the absorption of the others.
Kwashiorkor and
marasmus are childhood disorders caused by lack of dietary protein.
Moral, ethical, and health conscious diet
Many individuals limit what foods they eat for reasons of morality, or other habit. For instance
vegetarians choose to forgo food from animal sources to varying degrees. Others choose a healthier diet, avoiding sugars or animal fats and increasing consumption of dietary fiber and
antioxidants.
Obesity, a serious problem in the western world, leads to higher chances of developing
heart disease,
diabetes, and many other diseases. More recently, dietary habits have been influenced by the concerns that some people have about possible impacts on health or the environment from
genetically modified food. Further concerns about the impact of industrial farming (
grains) on
animal welfare, human health and the
environment are also having an effect on contemporary human dietary habits. This has led to the emergence of a
counterculture with a preference for
organic and
local food.
Nutrition
thumb|[[United States Department of Agriculture|USDA Food Pyramid]]
Between the extremes of optimal health and death from
starvation or
malnutrition, there is an array of disease states that can be caused or alleviated by changes in diet. Deficiencies, excesses and imbalances in diet can produce negative impacts on health, which may lead to diseases such as
scurvy,
obesity or
osteoporosis, as well as psychological and behavioral problems. The science of nutrition attempts to understand how and why specific dietary aspects influence health.
Nutrients in food are grouped into several categories. Macronutrients means fat, protein, and carbohydrates. Micronutrients are the
minerals and
vitamins. Additionally food contains water and
dietary fiber.
Legal definition
Some countries list a legal definition of food. These countries list food as any item that is to be processed, partially processed or unprocessed for consumption. The listing of items included as foodstuffs include any substance, intended to be, or reasonably expected to be, ingested by
humans. In addition to these foodstuffs, drink,
chewing gum, water or other items processed into said food items are part of the legal definition of food. Items not included in the legal definition of food include
animal feed, live animals unless being prepared for sale in a market, plants prior to harvesting, medicinal products,
cosmetics,
tobacco and tobacco products,
narcotic or
psychotropic substances, and residues and contaminants.
See also