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.
Energy Supply. Carbohydrates are the primary source of energy in the body. They are easy to digest and provide readily available energy that you need not only for physical activity, but for fueling all cellular and metabolic processes. Protein can be a source of energy, but it is not the body's preferred source.