Food is any substance consumed by a human or animal that provides energy and nutrients to sustain life and support growth. It is the basis for all biological systems, and it plays a key role in the maintenance of physical health and well-being.
A diet is a regular pattern of eating and drinking that is designed to promote good health. A healthy diet includes a variety of foods from all groups and is low in fat, salt, and sugars. It is high in fibre, vitamins and minerals. It also includes lean meats and fish, nuts, whole grains, beans and lentils and vegetables. It is important to avoid processed foods, as they are often high in saturated and trans fats, and low in nutrients.
There are many different kinds of food, but the most common are cereals; fruits; vegetables; meat, poultry, fish and eggs; milk and dairy products; and oils. Each of these contains different types of nutrients. It is important to eat a balanced diet, which means eating a little of each kind of food.
Eating too much food can lead to obesity, which can cause problems with health. Eating too little food, because of illness or anorexia, can lead to malnutrition. Some people cannot eat certain foods because of allergies or intolerances.
Most people rely on food produced by humans to satisfy their nutritional needs. Approximately two-thirds of the world’s population lives on cereal grains, such as wheat, barley, rice and maize (corn). These provide protein and essential fatty acids. The remainder of the world’s food supply is derived from plants, including vegetables and fruits. Some people choose not to eat food sourced from animals, such as meat, dairy or eggs, and instead consume plant-based foods. This is called vegetarianism.
Despite the widespread availability of processed food, some people prefer to cook their own meals. Such home-cooked meals are usually considered to be healthier than takeaway or restaurant food. However, cooking at home can be time-consuming and difficult for some people. It is possible to make nutritious meals using convenient, fast-cooking ingredients such as ready-made pasta sauces, frozen or canned vegetables and fruit, and dried beans or lentils.
Food is usually served with a fork, spoon, knife, chopsticks or a plate. It is often prepared with heat, either in a kitchen oven or a microwave. It may be stored in a refrigerator or freezer, or it may be preserved for long-term storage by canning, freezing, or drying. It can be eaten either hot or cold, and is normally consumed with other foods. It can be accompanied by drink, such as water, soft drinks or alcohol. It can be eaten in a restaurant, a home, or in school dining rooms (refectories). Sometimes it is prepared and distributed by professional cooks, chefs, or caterers. It can be bought in shops, markets, or street vendors. The cost of food can vary significantly. People with limited incomes can buy cheaper food from a food bank.