Food

Various foods

Food is any substance consumed to provide nutritional support for an organism. Food is usually of plant, animal or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingested by an organism and assimilated by the organism's cells to provide energy, maintain life, or stimulate growth. Different species of animals have different feeding behaviours that satisfy the needs of their unique metabolisms, often evolved to fill a specific ecological niche within specific geographical contexts.

Food sources

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.Corn (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. Some foods not from animal or plant sources include various edible fungi, especially mushrooms. Fungi and ambient bacteria are used in the preparation of fermented and pickled foods like leavened bread, alcoholic drinks, cheese, pickles, kombucha, and yogurt. Another example is blue-green algae such as Spirulina.Inorganic substances such as salt, baking soda and cream of tartar are used to preserve or chemically alter an ingredient.

Plants

Foods from plant sources

Many plants and plant parts are eaten as food and around 2,000 plant species are cultivated for food. Many of these plant species have several distinct cultivars.

Fruits are the ripened ovaries of plants, including the seeds within. Many plants and animals have coevolved such that the fruits of the former are an attractive food source to the latter, because animals that eat the fruits may 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 (potatoes and carrots), bulbs (onion family), leaf vegetables (spinach and lettuce), stem vegetables (bamboo shoots and asparagus), and inflorescence vegetables (globe artichokes and broccoli and other vegetables such as cabbage or cauliflower).

Animals

Various raw meats

Animals are 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 muscle systems or from organs (offal).

Food products produced by animals include milk produced by mammary glands, which in many cultures is drunk or processed into dairy products (cheese, butter, etc.). In addition, birds and other animals lay eggs, which are often eaten, and bees produce honey, a reduced nectar from flowers, which is a popular sweetener in many cultures. Some cultures consume blood, sometimes in the form of blood sausage, as a thickener for sauces, or in a cured, salted form for times of food scarcity, and others use blood in stews such as jugged hare.

Classifications and types of food

Adulterated food

Adulteration is a legal term meaning that a food product fails to meet the legal standards. One form of adulteration is an addition of another substance to a food item in order to increase the quantity of the food item in raw form or prepared form, which may result in the loss of actual quality of food item. These substances may be either available food items or non-food items. Among meat and meat products some of the items used to adulterate are water or ice, carcasses, or carcasses of animals other than the animal meant to be consumed.

Camping food

Freeze-dried bacon bars that can be used as camping food

Contents of a MRE package

Camping food includes ingredients used to prepare food suitable for backcountry camping and backpacking. The foods differ substantially from the ingredients found in a typical home kitchen. The primary differences relate to campers' and backpackers' special needs for foods that have appropriate cooking time, perishability, weight, and nutritional content.

To address these needs, camping food is often made up of either freeze-dried, precooked or dehydrated ingredients. Many campers use a combination of these foods.

Freeze-drying requires the use of heavy machinery and is not something that most campers are able to do on their own. Freeze-dried ingredients are often considered superior to dehydrated ingredients however because they rehydrate at camp faster and retain more flavor than their dehydrated counterparts. Freeze-dried ingredients take so little time to rehydrate that they can often be eaten without cooking them first and have a texture similar to a crunchy chip.

Diet food

A "low fat" child's meal from Burger King, with "apple fries" replacing fried potato chips, and a serving of macaroni and cheese as its main dish

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.

The process of making a diet version of a food usually requires finding an acceptable low-food-energy substitute for some high-food-energy ingredient.This can be as simple as replacing some or all of the food's sugar with a sugar substitute as is common with diet soft drinks such as Coca-Cola (for example Diet Coke). In some snacks, the food may be baked instead of fried thus reducing the food energy. In other cases, low-fat ingredients may be used as replacements.

Finger food

Afternoon tea finger foods

Finger food is food meant to be eaten directly using the hands, in contrast to food eaten with a knife and fork, spoon, chopsticks, or other utensils.In some cultures, food is almost always eaten with the hands; for example, Ethiopian cuisine is eaten by rolling various dishes up in injera bread.Foods considered street foods are frequently, though not exclusively, finger foods.

In the western world, finger foods are often either appetizers or entree/main course items. Examples of these are miniature meat pies, sausage rolls, sausages on sticks, cheese and olives on sticks, chicken drumsticks or wings, spring rolls, miniature quiches, samosas, sandwiches. 

Fresh food

Fresh fruits.

Fresh food is food which has not been preserved and has not spoiled yet. For vegetables and fruits, this means that they have been recently harvested and treated properly postharvest; for meat, it has recently been slaughtered and butchered; for fish, it has been recently caught or harvested and kept cold.

Dairy products are fresh and will spoil quickly. Thus, fresh cheese is cheese which has not been dried or salted for aging. Soured cream may be considered "fresh".

Fresh food has not been dried, smoked, salted, frozen, canned, pickled, or otherwise preserved.

Frozen food

Freezing food preserves it from the time it is prepared to the time it is eaten. Since early times, farmers, fishermen, and trappers have preserved grains and produce in unheated buildings during the winter season.Freezing food slows down decomposition by turning residual moisture into ice, inhibiting the growth of most bacterial species. In the food commodity industry, there are two processes: mechanical and cryogenic (or flash freezing). The kinetics of the freezing is important to preserve food quality and texture. Quicker freezing generates smaller ice crystals and maintains cellular structure. Cryogenic freezing is the quickest freezing technology available utilizing the extremely low temperature of liquid nitrogen −196 °C (−320 °F).

Health food

Health food is food marketed to provide human health effects beyond a normal healthy diet required for human nutrition. Foods marketed as health foods may be part of one or more categories, such as natural foods, organic foods, whole foods, vegetarian foods or dietary supplements. These products may be sold in health food stores or in the health food or organic sections of grocery stores.

Healthy food

A healthy diet is a diet that helps to maintain or improve overall health. A healthy diet provides the body with essential nutrition: fluid, macronutrients, micronutrients, and adequate calories.

For people who are healthy, a healthy diet is not complicated and contains mostly fruits, vegetables, and whole grains, and includes little to no processed food and sweetened beverages. The requirements for a healthy diet can be met from a variety of plant-based and animal-based foods, although a non-animal source of vitamin B12 is needed for those following a vegan diet. Various nutrition guides are published by medical and governmental institutions to educate individuals on what they should be eating to be healthy. Nutrition facts labels are also mandatory in some countries to allow consumers to choose between foods based on the components relevant to health.

Live food

"Pinkie" mice for sale as live food for reptiles

Live food is living food for carnivorous or omnivorous animals kept in captivity; in other words, small animals such as insects or mice fed to larger carnivorous or omnivorous species kept either in a zoo or as a pet.

Live food is commonly used as feed for a variety of species of exotic pets and zoo animals, ranging from alligators to various snakes, frogs and lizards, but also including other, non-reptile, non-amphibian carnivores and omnivores (for instance, skunks, which are omnivorous mammals, can technically be fed a limited amount of live food, though this is not a common practice).

Medical food

Novartis Fibersource HN medical food deployed on an IV pole

Medical foods are foods that are specially formulated and intended for the dietary management of a disease that has distinctive nutritional needs that cannot be met by normal diet alone. In the United States they were defined in the Food and Drug Administration's 1988 Orphan Drug Act Amendments^[and are subject to the general food and safety labeling requirements of the Federal Food, Drug, and Cosmetic Act. In Europe the European Food Safety Authority established definitions for "foods for special medical purposes" (FSMPs) in 2015.

Medical foods, called "food for special medical purposes" in Europe, are distinct from the broader category of foods for special dietary use, from traditional foods that bear a health claim, and from dietary supplements. 

Natural foods

The term “natural” is applied to many foods, but does not have a consistent meaning.

Natural foods and "all-natural foods" are widely used terms in food labeling and marketing with a variety of definitions, most of which are vague. The term is often assumed to imply foods that are not processed and whose ingredients are all natural products (in the chemist's sense of that term), thus conveying an appeal to nature. But the lack of standards in most jurisdictions means that the term assures nothing. In some countries, the term "natural" is defined and enforced. In others, such as the United States, it is not enforced.

“Natural foods” are often assumed to be foods that are not processed, or do not contain any food additives, or do not contain particular additives such as hormones, antibiotics, sweeteners, food colors, or flavorings that were not originally in the food. In fact, many people (63%) when surveyed showed a preference for products labeled "natural" compared to the unmarked counterparts, based on the common belief (86% of polled consumers) that the term "natural" indicated that the food does not contain any artificial ingredients.

Negative-calorie food

A negative-calorie food is food that supposedly requires more food energy to be digested than the food provides. Its thermic effect or specific dynamic action – the caloric "cost" of digesting the food – would be greater than its food energy content. Despite its recurring popularity in dieting guides, there is no scientific evidence supporting the idea that any food is calorically negative. While some chilled beverages are calorically negative, the effect is minimal and drinking large amounts of water can be dangerous.

Organic food

Organic fruits and vegetables at a farmers' market in Argentina

Organic food is food produced by methods that comply with the standards of organic farming. Standards vary worldwide, but organic farming in general features practices that strive to cycle resources, promote ecological balance, and conserve biodiversity. Organizations regulating organic products may restrict the use of certain pesticides and fertilizers in farming. In general, organic foods are also usually not processed using irradiation, industrial solvents or synthetic food additives.

Currently, the European Union, the United States, Canada, Mexico, Japan, and many other countries require producers to obtain special certification in order to market food as organic within their borders. In the context of these regulations, organic food is produced in a way that complies with organic standards set by regional organizations, national governments, and international organizations. 

Peasant foods

Acquacotta soup

Peasant foods are dishes specific to a particular culture, made from accessible and inexpensive ingredients, and usually prepared and seasoned to make them more palatable. They often form a significant part of the diets of people who live in poverty, or have a lower income compared to the average for their society or country.

Peasant foods have been described as being the diet of peasants, that is, tenant or poorer farmers and their farm workers, 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. 

Prison food

Prison food is the term for meals served to prisoners while incarcerated in correctional institutions. While some prisons prepare their own food, many use staff from on-site catering companies. Many prisons today support the requirements of specific religions, as well as vegetarianism.It is said that prison food of many developed countries is adequate to maintain health and dieting.

Seasonal food

"Seasonal" here refers to the times of the year when the harvest or the flavor of a given type of food is at its peak. This is usually the time when the item is harvested, with some exceptions; an example being sweet potatoes which are best eaten quite a while after harvest. It also appeals to people who prefer a low carbon diet that reduces the greenhouse gas emissions resulting from food consumption (Food miles).

Shelf-stable food

Packaged freeze-dried eggs can be shelf-stable

Shelf-stable food (sometimes ambient food) is food of a type that can be safely stored at room temperature in a sealed container. This includes foods that would normally be stored refrigerated but which have been processed so that they can be safely stored at room or ambient temperature for a usefully long shelf life.

Various food preservation and packaging techniques are used to extend a food's shelf life. Decreasing the amount of available water in a product, increasing its acidity, or irradiating or otherwise sterilizing the food and then sealing it in an air-tight container are all ways of depriving bacteria of suitable conditions in which to thrive. All of these approaches can all extend a food's shelf life without unacceptably changing its taste or texture.

Space food

Food aboard the Space Shuttle served on a tray. Note the use of magnets, springs, and Velcro to hold the cutlery and food packets to the tray

Space food is a type of food product created and processed for consumption by astronauts in outer space. The food has specific requirements of providing balanced nutrition for individuals working in space while being easy and safe to store, prepare and consume in the machinery-filled weightless environments of crewed spacecraft.

In recent years, space food has been used by various nations engaging in space programs as a way to share and show off their cultural identity and facilitate intercultural communication. Although astronauts consume a wide variety of foods and beverages in space, the initial idea from The Man in Space Committee of the Space Science Board in 1963 was to supply astronauts with a formula diet that would supply all the needed vitamins and nutrients.

Traditional food

Traditional foods are foods and dishes that are passed through generations or which have been consumed many generations. Traditional foods and dishes are traditional in nature, and may have a historic precedent in a national dish, regional cuisine or local cuisine. Traditional foods and beverages may be produced as homemade, by restaurants and small manufacturers, and by large food processing plant facilities.

Some traditional foods have geographical indications and traditional specialities in the European Union designations per European Union schemes of geographical indications and traditional specialties: Protected designation of origin (PDO), Protected geographical indication (PGI) and Traditional specialities guaranteed (TSG). 

Whole food

Whole foods are plant foods that are unprocessed and unrefined, or processed and refined as little as possible, before being consumed.Examples of whole foods include whole grains, tubers, legumes, fruits, vegetables.

There is some confusion over the usage of the term surrounding the inclusion of certain foods, in particular animal foods. The modern usage of the term whole foods diet is now widely synonymous with "whole foods plant-based diet" with animal products, oil and salt no longer constituting whole foods.

The earliest use of the term in the post-industrial age appears to be in 1946 in The Farmer, a quarterly magazine published and edited from his farm by F. Newman Turner, a writer and pioneering organic farmer. 

Cuisine

Typical Balinese cuisine in Indonesia

Many scholars claim that the rhetorical function of food is to represent the culture of a country, and that it can be used as a form of communication. According to Goode, Curtis and Theophano, food "is the last aspect of an ethnic culture to be lost".

Some popular types of ethnic foods include Italian, French, Japanese, Chinese, American, Cajun, Thai, African, Indian and Nepalese. 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 than others, for evolutionary purposes.

Presentation

A French basil salmon terrine, with eye-appealing garnishes

Aesthetically pleasing and eye-appealing food presentations can encourage people to consume foods. A common saying is that people "eat with their eyes". Food presented in a clean and appetizing way will encourage a good flavor, even if unsatisfactory.

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.

Another universal phenomenon regarding food is the appeal of contrast in taste and presentation.

Food preparation

While many foods can be eaten raw, many also undergo some form of preparation for reasons of safety, palatability, texture, 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; 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.

Raw food preparation

Many types of fish ready to be eaten, including salmon and tuna

Certain cultures highlight animal and vegetable foods in a 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 seafood. Steak tartare and salmon tartare are dishes made from diced or ground raw beef or salmon, mixed with various ingredients and served with baguettes, brioche, or frites.In Italy, carpaccio is a dish of very thinly sliced raw beef, drizzled with a vinaigrette made with olive oil.The 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 °F .

Cooking

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 cook.The diversity of cooking worldwide is a reflection of the myriad nutritional, aesthetic, agricultural, economic, cultural, and religious considerations that affect it.

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.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.

Cooking equipment

There are many different types of equipment used for cooking.

Ovens are mostly hollow devices that get very hot (up to 500 °F (260 °C)) and are 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, which is a cylindrical clay oven which operates at a single high temperature.Western kitchens use variable temperature convection ovens, conventional ovens, toaster ovens, or non-radiant heat ovens like the microwave oven. Classic Italian cuisine includes the use of a brick oven containing burning wood. Ovens may be wood-fired, coal-fired, gas, electric, or oil-fired.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, or pressure cooker. 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, and deep-frying.

In 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-pit 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.

Restaurants

Restaurants employ chefs to prepare the food, and waiters to serve customers at the table.The term restaurant comes from an old term for a restorative meat broth; this broth (or bouillon) was served in elegant outlets in Paris from the mid 18th century.These refined "restaurants" were a marked change from the usual basic eateries such as inns and taverns,and some had developed from early Parisian cafés, such as Café Procope, by first serving bouillon, then adding other cooked food to their menus.

Commercial eateries existed during the Roman period, with evidence of 150 "thermopolia", a form of fast food restaurant, found in Pompeii,and urban sales of prepared foods may have existed in China during the Song dynasty.

In 2005, the population of the United States spent $496 billion on 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.

Food security

A woman selling produce at a market in Lilongwe, Malawi.

A farmer holding up onions he has grown on his farm near Gilgil, Kenya.

Food security is a measure of the availability of food and individuals' ability to access it. According the United Nations’ Committee on World Food Security, food security is defined as meaning that all people, at all times, have physical, social, and economic access to sufficient, safe, and nutritious food that meets their food preferences and dietary needs for an active and healthy life.The availability of food irrespective of class, gender or region is another one. There is evidence of food security being a concern many thousands of years ago, with central authorities in ancient China and ancient Egypt being known to release food from storage in times of famine. At the 1974 World Food Conference the term "food security" was defined with an emphasis on supply; food security is defined as the "availability at all times of adequate, nourishing, diverse, balanced and moderate world food supplies of basic foodstuffs to sustain a steady expansion of food consumption and to offset fluctuations in production and prices".Later definitions added demand and access issues to the definition. The first World Food Summit, held in 1996, stated that food security "exists when all people, at all times, have physical and economic access to sufficient, safe and nutritious food to meet their dietary needs and food preferences for an active and healthy life."

Similarly, household food security is considered to exist when all members, at all times, have access to enough food for an active, healthy life.Individuals who are food secure do not live in hunger or fear of starvation.Food insecurity, on the other hand, is defined by the United States Department of Agriculture (USDA) as a situation of "limited or uncertain availability of nutritionally adequate and safe foods or limited or uncertain ability to acquire acceptable foods in socially acceptable ways".Food security incorporates a measure of resilience to future disruption or unavailability of critical food supply due to various risk factors including droughts, shipping disruptions, fuel shortages, economic instability, and wars.

The Food and Agriculture Organization of the United Nations, or FAO, identified the four pillars of food security as availability, access, utilization, and stability.The United Nations (UN) recognized the Right to Food in the Declaration of Human Rights in 1948,and has since said that it is vital for the enjoyment of all other rights.

The 1996 World Summit on Food Security declared that "food should not be used as an instrument for political and economic pressure".Since multiple different international agreements and mechanisms have been developed to address food security. The main global policy to reduce hunger and poverty is in the Sustainable Development Goals. In particular Goal 2: Zero Hunger sets globally agreed on targets to end hunger, achieve food security and improved nutrition, and promote sustainable agriculture by 2030.