Food is any material consumed to supply nutrition to an organism. In nature food is generally of animal, plant or fungi origin, and usually contains various essential nutrients, including proteins, fats, carbohydrates, vitamins, or other minerals. The food that humans eat comes mainly from plant sources, although in some cases animal products can also be eaten. There are five major food groups: whole foods, which include all the edible parts of a plant; vegetable foods, which include all the parts not plant-based and also derive nourishment from some part of the plant; legumes, which include beans, peas, nuts, seeds and stems; and processed food, which refers to any food that has been altered chemically. Foods are categorized on the basis of their nutritional value.
Animal foods include meat, milk and eggs, fish, other seafood, and birds’ eggs. Plant-based foods include vegetables, whole grains, fruits, and nuts. These provide a variety of nutrients including vitamins, carbohydrates, proteins and fats. Fats are contained in butter and other animal fats, oils derived from certain plants (such as palm oil), coconut oil, shortening and processed vegetable oils, and fats derived from bones, liver, kidneys and other animals. The human body needs carbohydrates to produce energy, whereas carbohydrates are not needed by the body but provide some dietary fiber.
Dairy products include cheese, yoghurt, butter, ice cream, milk, yogurt, butter and other dairy products. Processed food usually has two main ingredients, sugar and salt. Sugar is used to make juices, candy, cocoa, chocolate and other sweet products; salt is used for seasoning and cooking purposes. Fresh fruits and vegetables, whole grain breads and cereals, fresh dairy products, fish that contain omega-3 fatty acids, poultry meat, eggs, rice, beans, lentils, nuts, seeds, mushrooms, starchy vegetables and legumes are all nutritious. To get the recommended daily allowance of each of these nutritional groups, it would be necessary to consume a large amount of fresh food everyday.