Food is any material food consumed by an organism to give nutrition to it. The major groups of foods are animal, vegetable and fungus, although bacteria and some protozoa are also considering food. Food is generally of animal, plant or fungi origin, and is made up of various constituents, including proteins, fats, carbohydrates, vitamins, or mineral ions. Food is divided into components based on where they derive from. Animal food is meat, milk, eggs and other dairy products, whereas plant food is starchy carbohydrates, starches and vegetables, whereas fungi and bacteria are fed with protein. Fungi are the only animals that produce food, whereas all other forms of food are consumed by us humans.

The major components in most types of food are fat, carbohydrate, protein, mineral salts, ions and vitamins. When food is digested, three main components are released: amino acids (protein units), free fatty acids (fatty acids), and chemicals called non-nutritive compounds or NN’s. Amino acids and free fatty acids have a wide range of roles in human nutrition and health, with the function of each serving of food determined by how much nutrition it has and how it is digested by the body. However, the NN’s have very important roles in immunity and disease, especially when large amounts of food are ingested.

Human beings need a varied amount of amino acids and fatty acids, which are contained in plants, in order to survive. Plants only contain two of the essential amino acids, thus plants and animal products form the basis of our diets, with animal products accounting for the rest. The lack of protein in plant products means that humans can only rely on animal products for the provision of the protein, leading to serious deficiencies in the absorption of important nutrients in the diet, which is a major cause of the rising number of overweight people in the Western world. As with any type of diet, complete proteins are needed to meet nutritional needs, and a balanced diet is always the first step in an individual’s attempt at good health and nutrition.