Protein is needed to provide the body with amino acids, and is a major component in muscle, hair, nails, and skin. However, not all proteins are created equal. The soy protein is known as a complete protein, which means that it contains all of the essential amino acids. It is also known to contain very little fat, cholesterol, or lactose. For vegetarians and those who are lactose intolerant, soy protein is a good option to get a non-animal protein in the diet. In addition to the usual benefits of a good protein, soy proteins contain saponins, phytosterols and isoflavones. These various components have been demonstrated to have a range of positive health effects, from lowering cholesterol levels to improving the immune system.