Fresh food
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" (crème fraîche).
Fresh food has not been dried, smoked, salted, frozen, canned, pickled, or otherwise preserved.[36]
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.[37] 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).[38]
Preserving food in domestic kitchens during modern times is achieved using household freezers. Accepted advice to householders was to freeze food on the day of purchase. An initiative by a supermarket group in 2012 (backed by the UK's Waste & Resources Action Programme) promotes the freezing of food "as soon as possible up to the product's 'use by' date". The Food Standards Agency was reported as supporting the change, providing the food had been stored correctly up to that time.[39]
Functional food
A functional food is a food given an additional function (often one related to health-promotion or disease prevention) by adding new ingredients or more of existing ingredients.[40] The term may also apply to traits purposely bred into existing edible plants, such as purple or gold potatoes having enriched anthocyanin or carotenoid contents, respectively.[41] Functional foods may be "designed to have physiological benefits and/or reduce the risk of chronic disease beyond basic nutritional functions, and may be similar in appearance to conventional food and consumed as part of a regular diet".[42]
The term was first used in Japan in the 1980s where there is a government approval process for functional foods called Foods for Specified Health Use (FOSHU).[43]
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.[44][45]
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.[46] 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.[47]
A healthy lifestyle includes getting exercise every day along with eating a healthy diet. A healthy lifestyle may lower disease risks, such as obesity, heart disease, type 2 diabetes, hypertension and cancer.[44][48]
There are specialized healthy diets, called medical nutrition therapy, for people with various diseases or conditions. There are also prescientific ideas about such specialized diets, as in dietary therapy in traditional Chinese medicine.
The World Health Organization (WHO) makes the following 5 recommendations with respect to both populations and individuals:[49]
- Maintain a healthy weight by eating roughly the same number of calories that your body is using.
- Limit intake of fats. Not more than 30% of the total calories should come from fats. Prefer unsaturated fats to saturated fats. Avoid trans fats.
- Eat at least 400 grams of fruits and vegetables per day (potatoes, sweet potatoes, cassava and other starchy roots do not count). A healthy diet also contains legumes (e.g. lentils, beans), whole grains and nuts.
- Limit the intake of simple sugars to less than 10% of calorie (below 5% of calories or 25 grams may be even better)[50]
- Limit salt / sodium from all sources and ensure that salt is iodized. Less than 5 grams of salt per day can reduce the risk of cardiovascular disease.[51]
Live food
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). Common live food ranges from crickets (used as an inexpensive form of feed for carnivorous and omnivorous reptiles such as bearded dragons and commonly available in pet stores for this reason), waxworms, mealworms and to a lesser extent cockroaches and locusts, to small birds and mammals such as mice or chickens.
Natural foods
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.[57] 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.[58] The terms are variously used and misused on labels and in advertisements.[59]
The international Food and Agriculture Organization’s Codex Alimentarius does not recognize the term “natural” but does have a standard for organic foods.[60]
Food
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.
Omnivorous humans are highly adaptable and have adapted to obtain food in many different ecosystems. Historically, humans secured food through two main methods: hunting and gathering and agriculture. As agricultural technologies increased, humans settled into agriculture lifestyles with diets shaped by the agriculture opportunities in their geography. Geographic and cultural differences has led to creation of numerous cuisines and culinary arts, including a wide array of ingredients, herbs, spices, techniques, and dishes. As cultures have mixed through forces like international trade and globalization, ingredients have become more widely available beyond their geographic and cultural origins, creating a cosmopolitan exchange of different food traditions and practices.
Today, the majority of the food energy required by the ever-increasing population of the world is supplied by the industrial food industry, which produces food with intensive agriculture and distributes it through complex food processing and food distribution systems. This system of conventional agriculture relies heavily on fossil fuels, which means that the food and agricultural system is one of the major contributors to climate change, accountable for as much as 37% of total greenhouse gas emissions.[1] Addressing the carbon intensity of the food system and food waste are important mitigation measures in the global response to climate change.
The food system has significant impacts on a wide range of other social and political issues including: sustainability, biological diversity, economics, population growth, water supply, and access to food. The right to food is a human right derived from the International Covenant on Economic, Social and Cultural Rights (ICESCR), recognizing the "right to an adequate standard of living, including adequate food", as well as the "fundamental right to be free from hunger". Because of these fundamental rights, food security is often a priority international policy activity; for example Sustainable Development Goal 2 "Zero hunger" is meant to eliminate hunger by 2030. Food safety and food security are monitored by international agencies like the International Association for Food Protection, World Resources Institute, World Food Programme, Food and Agriculture Organization, and International Food Information Council, and are often subject to national regulation by institutions, like the Food and Drug Administration in the United States.
Contents
- 1Definition and classification
- 2Food sources
- 3Classifications and types of food
- 3.1Adulterated food
- 3.2Camping food
- 3.3Diet food
- 3.4Finger food
- 3.5Fresh food
- 3.6Frozen food
- 3.7Functional food
- 3.8Health food
- 3.9Healthy food
- 3.10Live food
- 3.11Medical food
- 3.12Natural foods
- 3.13Negative-calorie food
- 3.14Organic food
- 3.15Peasant foods
- 3.16Prison food
- 3.17Seasonal food
- 3.18Shelf-stable food
- 3.19Space food
- 3.20Traditional food
- 3.21Whole food
- 4Taste perception
- 5Cuisine
- 6Economy
- 7Problems
- 8Policy
- 9Safety
- 10Diet
- 11See also
- 12References
- 13Further reading
- 14External links
Definition and classification
Food is any substance consumed to provide nutritional support for an organism.[2] It can be raw, processed or formulated and is consumed orally by animals for growth, health or pleasure. Food is mainly composed of water, lipids, proteins and carbohydrates. Minerals (e.g salts) and organic substances (e.g vitamins) can also be found in food.[3] Plants, algae and some microorganisms use photosynthesis to make their own food molecules.[4] Water is found in many foods and has been defined as a food by itself.[5] Food provides energy and nutrition to the organism. Water and fiber have low energy densities, or calories, while fat is the most energy dense component.[6]
Human food can be classified in various ways, either by related content or by how the food is processed.[7] The number and composition of food groups can vary. Most systems include four basic groups that describe their origin and relative nutritional function: Vegetables and Fruit, Cereals and Bread, Dairy, and Meat.[8] Studies that look into diet quality often group food into whole grains/cereals, refined grains/cereals, vegetables, fruits, nuts, legumes, eggs, dairy products, fish, red meat, processed meat, and sugar-sweetened beverages.[9][10][11] The Food and Agriculture Organization and World Health Organization use a system with nineteen food classifications: cereals, roots, pulses and nuts, milk, eggs, fish and shellfish, meat, insects, vegetables, fruits, fats and oils, sweets and sugars, spices and condiments, beverages, foods for nutritional uses, food additives, composite dishes and savoury snacks.[12]
Food sources
In a given ecosystem, food forms a web of interlocking chains with primary producers at the bottom and apex predators at the top.[13] Other aspects of the web include detrovores (that eat detritis) and decomposers (that break down dead organisms).[13] Primary producers include algae, plants, bacteria and protists that acquire their energy from sunlight.[14] Primary consumers are the herbivores that consume the pants and secondary consumers are the carnivores that consume those herbivores. Some organisms, including most mammals and birds, diets consist of both animals and plants and they are considered omnivores.[15] The chain ends in the apex predator, the animal that has no known predators in its ecosystem.[16] Humans are often considered apex predators.[17]
Humans are omnivores finding sustenance in vegetables, fruits, cooked meat, milk, eggs, mushrooms and seaweed.[15] Cereal grain is a staple food that provides more food energy worldwide than any other type of crop.[18] Corn (maize), wheat, and rice account for 87% of all grain production worldwide.[19][20][21] Most of the grain that is produced worldwide is fed to livestock. We also use fungi and ambient bacteria 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.[22] Inorganic substances such as salt, baking soda and cream of tartar are used to preserve or chemically alter an ingredient.
Plants
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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.[23]
Seeds of plants are a good source of food for animals, including humans, because they contain the nutrients necessary for the plant's initial growth, including many healthful fats, such as omega fats. In fact, the majority of food consumed by human beings are seed-based foods. Edible seeds include cereals (corn, wheat, rice, et cetera), legumes (beans, peas, lentils, et cetera), and nuts. Oilseeds are often pressed to produce rich oils - sunflower, flaxseed, rapeseed (including canola oil), sesame, etc.[24]
Seeds are typically high in unsaturated fats and, in moderation, are considered a health food. However, not all seeds are edible for humans. Large seeds, such as those from a lemon, pose a choking hazard, while seeds from cherries and apples contain cyanide which could be poisonous only if consumed in large volumes.[25] Birds are also well-known for feeding on seeds (for more information, see birdseed).
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. Animals that eat fruits are known as frugivores. One such coevolutionary relationship involves primates, who are primarily frugivorous.[26] 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.[27] (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).[28]
Animals
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.[29]
Some cultures and people do not consume meat or animal food products for cultural, dietary, health, ethical, or ideological reasons. Vegetarians choose to forgo food from animal sources to varying degrees. Vegans do not consume any foods that are or contain ingredients from an animal source.
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.[30]
Camping food
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.
Dehydration can reduce the weight of the food by sixty to ninety percent by removing water through evaporation. Some foods dehydrate well, such as onions, peppers, and tomatoes.[31][32] Dehydration often produces a more compact, albeit slightly heavier, result than freeze-drying.
Surplus precooked military Meals, Meals, Ready-to-Eat (MREs) are sometimes used by campers. These meals contain pre-cooked foods in retort pouches. A retort pouch is a plastic and metal foil laminate pouch that is used as an alternative to traditional industrial canning methods.
Diet food
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.[33] 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.
In whole grain foods, the higher fiber content effectively displaces some of the starch components of the flour. Since certain fibers have no food energy, this results in a modest energy reduction. Another technique relies on the intentional addition of other reduced-food-energy ingredients, such as resistant starch or dietary fiber, to replace part of the flour and achieve a more significant energy reduction.
Finger food
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.[34] 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.[35] Foods considered street foods are frequently, though not exclusively, finger foods.
In the western world, finger foods are often either appetizers (hors d'œuvres) 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, Merenda or other such based foods, such as pitas or items in buns, bhajjis, potato wedges, vol au vents, several other such small items and risotto balls (arancini). Other well-known foods that are generally eaten with the hands include hamburgers, pizza, chips, hot dogs, fruit and bread.
In Greater China, foods like pancakes or flatbreads (bing 饼) and street foods such as chuan (串, also pronounced chuan) are often eaten with the hands.
Medical food
Main article: 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[52] 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.[53]
Medical foods, called "food for special medical purposes" in Europe,[54] are distinct from the broader category of foods for special dietary use, from traditional foods that bear a health claim, and from dietary supplements. In order to be considered a medical food the product must, at a minimum:[55][56]
- be a food for oral ingestion or tube feeding (nasogastric tube)
- be labeled for the dietary management of a specific medical disorder, disease or condition for which there are distinctive nutritional requirements, and
- be intended to be used under medical supervision.
Medical foods can be classified into the following categories:
- Nutritionally complete formulas
- Nutritionally incomplete formulas
- Formulas for metabolic disorders
- Oral rehydration products
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[61] and drinking large amounts of water can be dangerous.