Protein is a nutrient which is essential to the human body, particularly for the muscle tissues. Nutritionists recommend a daily intake of about .3 grams of protein for every pound of body weight. Bodybuilders and other athletes, however require more protein in their diets to encourage muscle growth and to nourish their bodies to handle the demands of their workouts. These people should get about 1.25 grams/day of protein for each pound of body weight.