Asteroids range in size from Ceres-the largest at about 950 kilometers (590 miles) in diameter and also identified as a dwarf planet-to bodies that are less than 1 kilometer (0.6 mile) across. The total mass of all the asteroids combined is less than that of Earth's Moon.
Only about one-third of the protein eaten around the world comes from animals raised for food. Much of the protein consumed around the world comes from vegetarian sources, including grains, legumes, nuts and seeds. Three grains -- wheat, maize and rice -- provide 60 percent of the world's energy, as well as a good percentage of the protein consumed.
Sources of Protein. Protein is derived from animal and plant sources. Animal sources include meat, poultry, eggs, fish and dairy products. These contain the nine essential amino acids and are classified as complete proteins. Plant sources include vegetables, beans, nuts and legumes. They lack the essential amino acids.