Food is any material consumed in order to provide nutrients to an organisms internal organs. More specifically, food is of plant, animal, or fungi origin, and generally contains vital nutrients, including vitamins, proteins, carbohydrates, and fats. Every living cell that requires nourishment can derive nourishment from food. The majority of food, or food supply is obtained through plants and animals; these include all food types, from the vegetable, to the fruit, to nuts and seeds. Animal food products also provide food, which we eat indirectly, by being consumed by us and indirectly via fertilization and antibiotics.

Fats, oils, emulsions, and solids are some of the components that constitute food. These constituents are known collectively as fats, oils, emulsions, and solids. Most of the fat, if not all, that we consume comes from animal sources. Animal source foods include meat, dairy products, eggs, milk, cheese, and partly processed foods such as white bread, cookies, cakes, dried and processed vegetables, and hydrogenated fats (petrochemicals that give foods an oily surface). Saturated fats are the major component of most animal fat.

Fruits and vegetables are the richest sources of nutrition. Vegetables include all those varieties of plants that are eaten directly, such as broccoli, spinach, carrots, corn, peas, beans, squash, tomatoes, and watermelons; and fruits include all those varieties of plants that are eaten indirectly, such as cranberries, strawberries, prunes, pineapples, kiwi, honey, orange juice, bananas, apples, pears, peaches, and oranges. All these food groups are equally important for good health and should be eaten daily. Those with a special diet need to eat more variety and less food from each food group. Some examples of such special diets are diabetic patients, vegetarians, and pregnant women.