Food: Food is consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals.
Food Sources: Most food has its origin in plants. Cereal grain is a staple food that provides more food energy worldwide than any other type of crop. Maize, wheat, and rice – in all of their varieties – account for 87% of all grain production worldwide. Most of the grain that is produced worldwide is fed to livestock which are also raised as source of food for human consumption. Some foods not from animal or plant sources include various edible fungi, especially mushrooms. Fungi and ambient bacteria are used in the preparation of fermented and pickled foods like leavened bread, alcoholic drinks, cheese, pickles and yogurt. Another example is blue-green algae such as Spirulina. Inorganic substances such as salt, baking soda and cream of tartar are used to preserve or chemically alter an ingredient.
Plants: There are around 2,000 plant species which are cultivated for food. Seeds of plants are a good source of food. Edible seeds include cereals (maize, wheat, rice, et cetera), legumes (beans, peas, lentils, et cetera), and nuts. Oilseeds are often pressed to produce rich oils - sunflower, flaxseed, rapeseed (including canola oil) and sesame. Seeds are typically high in unsaturated fats and, in moderation, are considered a health food, although not all seeds are edible. Large seeds, such as those from a lemon, pose a choking hazard, while seeds from apples and cherries contain the poisonous substance cyanide. Fruits are the ripened ovaries of plants, including the seeds within. Vegetables are a second type of plant matter that is commonly eaten as food. These include root vegetables (potatoes and carrots), bulbs (onion family), leaf vegetables (spinach and lettuce), stem vegetables (bamboo shoots and asparagus), and inflorescence vegetables (artichokes, broccoli, cabbage and cauliflower).
Animals: Meat is an example of a direct product taken from an animal, which comes from muscle systems or from organs. Food products produced by animals include dairy products like milk, cheese, butter, etc. Eggs and honey are other examples. Nutrition also called nourishment or aliment is providing nutrients necessary for supporting life of organisms.