Food is any substance consumed to provide nutritional support for an organism. Food is usually of plant, animal, or fungal in 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 behaviors 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 agricultural lifestyles with diets shaped by the agriculture opportunities in their geography. 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 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
(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.
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.
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, et cetera.
Seeds are typically high in unsaturated fats and, in moderation, are considered healthy food. However, not all seeds are edible. 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.
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.
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 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 the 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.
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.
