Food is any nutrient-rich material consumed or absorbed by plants or animals in order to sustain life. It includes both plant and animal sources, and some people choose to abstain from eating animal products, which is known as vegetarianism. Other people may eat only certain types of foods, such as vegetables or grains. Some people prefer to cook their own meals, rather than eat at restaurants or other homes; they are known as home chefs or “foodies.”
The food industry involves all aspects of supplying humans with the food and beverages that they consume. Some foods are grown or raised in fields or gardens, while others come from livestock, wild animals, and fish. In the past, many people hunted or gathered their own food, but now most of us purchase our food at stores or from restaurants.
Despite the fact that most of us live in industrialized nations, food remains a significant part of local culture, with some dishes unique to particular regions. It can also be a point of pride, a way to honor the heritage of a family or country, or a way to express cultural identity.
Some foods are processed to make them easier to prepare or more convenient, such as canned vegetables and pre-chopped or frozen meats. Processing may also include adding salt, sugar, or other flavorings. During this process, some nutrients may be lost, such as vitamins and minerals. Luckily, some of these are added back after processing, such as fortified cereals or reconstituted fruits.
Other foods are not processed and are ready to eat when purchased at markets or from street vendors. These include meat, fish, poultry, and eggs, as well as cheeses, breads, and pastries. The production, storage, and distribution of these foods requires large amounts of water, energy, and land, which can have adverse environmental effects.
Food is a fundamental need for all human beings. Some people suffer from a lack of food, which can lead to malnutrition and disease. Others eat too much, which can cause obesity and other health problems. Some people cannot eat certain foods because of medical conditions such as Coeliac disease or allergies.
A food allergy is an immune system response to a specific food. Some common food allergies include peanuts, shellfish, dairy, and soy.
A food chain is a sequence of organisms that receive their energy and nutrition from other organisms in the same species. The primary source of energy for all living things is glucose (a type of carbohydrate), which is found in plants and animals. Glucose is used for cell growth and metabolism. Other types of energy, such as fats and proteins, are also found in foods. Some organisms use both simple and complex carbohydrates for energy, while some solely use simple carbohydrates. Carbohydrates can be converted to energy by the body or into fat, which is stored in the body. Fats are also sources of cholesterol, a fatty substance that contributes to heart disease.