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.
While much of the protein in the American diet comes from beef and pork, this isn't necessarily the case around the world. People in some countries eat little or no meat, getting much of their protein from vegetarian protein sources, and some people get their protein from foods many Americans have never tried.
Protein can be metabolized for energy when carbohydrate and fat are in short supply. According to Gordon Wardlaw and Anne Smith in their text Contemporary Nutrition, proteins comprise 17% of your body weight, which except for water, forms the majority of lean tissue. Dietary protein supplies your body with essential nitrogen, which is then used to reformulate needed body proteins.