Human food
Human food is food which is fit for human consumption, and which humans willingly eat. Food is a basic necessity of life, and humans typically seek food out as an instinctual response to hunger; however, not all things that are edible constitute as human food.
Humans eat various substances for energy, enjoyment and nutritional support. These are usually of plant, animal, or fungal origin, and contain essential nutrients, such as carbohydrates, fats, proteins, vitamins, and minerals. Humans are highly adaptable omnivores, 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 improved, humans settled into agriculture lifestyles with diets shaped by the agriculture opportunities in their region of the world. Geographic and cultural differences have led to the 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 the total greenhouse gas emissions. 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, 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, such as the Food and Drug Administration in the United States.
Food sources
Humans are omnivores finding sustenance in vegetables, fruits, cooked meat, milk, eggs, mushrooms and seaweed. Cereal grain is a staple food that provides more food energy worldwide than any other type of crop. Corn, wheat, and rice account for 87% of all grain production worldwide. Just over half of the world's crops are used to feed humans, with 36 percent grown as animal feed and 9 percent for biofuels. Fungi and bacteria are also used in the preparation of fermented foods like bread, wine, cheese and yogurt.Humans eat thousands of plant species; there may be as many as 75,000 edible species of angiosperms, of which perhaps 7,000 are often eaten. Most human plant-based food calories come from maize, rice, and wheat. Plants can be processed into bread, pasta, cereals, juices and jams, or raw ingredients such as sugar, herbs, spices and oils can be extracted. Oilseeds are often pressed to produce rich oils: sunflower, flaxseed, rapeseed and sesame.
Animals may be used as food either directly or indirectly. This includes meat, eggs, shellfish and dairy products like milk and cheese. They are an important source of protein and are considered complete proteins for human consumption, as they contain all the amino acids essential for the human body. 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 contain ingredients from an animal source.
Fish and other marine animals are harvested from lakes, rivers, wetlands, inland waters, coasts, estuaries, mangroves, near-shore areas, and marine and ocean waters. Although aquatic foods contribute significantly to the health of billions of people around the world, they tend to be undervalued nutritionally, primarily because their diversity is framed in a monolithic way as "seafood or fish." Worldwide, aquatic foods are available every season and are produced in a wide variety. Over 2,370 species are harvested from wild fisheries, and about 624 are farmed in aquaculture. Fish powder for infants, fish wafers for snacks, and fish chutneys have all been developed because marine foods are nutrient-dense.
Taste perception
Some animals, specifically humans, have five different types of tastes: sweet, sour, salty, bitter, and umami. As such animals have evolved, the tastes that provide the most energy are the most pleasant to eat while others, such as bitter, are not enjoyable. Water, while important for survival, has no taste. Fats, on the other hand, especially saturated fats, are thicker and rich and are thus considered more enjoyable to eat.Sweet
Generally regarded as the most pleasant taste, sweetness is almost always provided by a type of simple sugar such as glucose or fructose, or disaccharides such as sucrose, a molecule combining glucose and fructose. Complex carbohydrates are long chains and do not have a sweet taste.In the natural settings that human primate ancestors evolved in, sweetness intensity should indicate energy density, while bitterness tends to indicate toxicity. The high sweetness detection threshold and low bitterness detection threshold would have predisposed our primate ancestors to seek out sweet-tasting foods and avoid bitter-tasting foods.
Artificial sweeteners such as sucralose are used to mimic the sugar molecule, creating the sensation of sweetness, without the energy. The stevia plant contains a compound known as steviol which, when extracted, has 300 times the sweetness of sugar while having minimal impact on blood sugar.
Sour
ness is caused by the taste of acids, such as vinegar in alcoholic beverages. Sour foods include citrus, specifically lemons, limes, and to a lesser degree oranges. Sour is evolutionarily significant as it is a sign of food that may have gone rancid due to bacteria. Many foods, however, are slightly acidic and help stimulate the taste buds and enhance flavour.Salty
is the taste of alkali metal ions such as sodium and potassium. It is found in almost every food in low to moderate proportions to enhance flavour, although eating pure salt is regarded as highly unpleasant. There are many different types of salt, with each having a different degree of saltiness, including sea salt, fleur de sel, kosher salt, mined salt, and grey salt.Other than enhancing flavour, salty foods are significant for body needs and maintaining a delicate electrolyte balance, which is the kidney's function. Salt may be iodized, meaning iodine has been added to it. Iodine is a necessary nutrient for maintenance of thyroid function, and the addition of iodine to salt became a public-health practice in the mid 20th century to prevent iodine deficiency and related diseases such as endemic goitre.
Some canned foods, notably soups or packaged broths, tend to be high in salt as a means of preserving the food longer. Historically salt has long been used as a meat preservative as salt promotes water excretion. Similarly, dried foods also promote food safety.
Bitter
is a sensation often considered unpleasant and characterized by having a sharp, pungent taste. Unsweetened dark chocolate, caffeine, lemon rind, and some types of fruit are known to be bitter.Umami
has been described as savoury and is characteristic of broths and cooked meats. Foods that have a strong umami flavor include meats, shellfish, fish, tomatoes, mushrooms, hydrolyzed vegetable protein, meat extract, yeast extract, cheeses, and soy sauce.Cuisine
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".Many cultures have a recognizable cuisine, a specific set of cooking traditions using various spices or a combination of flavours unique to that culture, which evolves. Other differences include preferences and practices, the study of which is known as gastronomy. Many cultures have diversified their foods by utilizing 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, 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 flavour from eating and drinking. Certain tastes are more enjoyable than others, for evolutionary purposes.