Dietary sources of protein are either complete or incomplete protein . Complete proteins contain all the essential amino acids our bodies cannot make and are therefore vital in our diets in small amounts. By contrast, incomplete proteins, which come from mainly plant sources, can be combined to make a complete protein. Protein is vital to maintaining immune function, producing hormones and enzymes, healing tissue, and have a role in athletic performance as a component of hemoglobin and myoglobin. These tissues are involved in oxygen transport to muscles.
Protein can also supply the body with energy during starvation or intense exercise.
How much protein your body needs is dependent on your weight, the amount of calories you consume, and your degree and intensity of training. If overall calorie or energy needs are not met, then the protein you eat will be used by the body for energy instead of for vital functions. Protein needs are greatest for endurance athletes such as distance runners, swimmers, soccer players, cross-country skiers, triathletes, and road cyclists. Multiply your weight in pounds by 0.5 - 0. 7 grams protein per pound.