Yams contain relatively little protein. Your body uses protein to build muscle, repair tissue and synthesize biological molecules such as enzymes and hormones. Protein also functions as a fuel source for your body if you donandt consume enough carbohydrates. Registered Dietitian Nancy Clark recommends a daily protein intake of 0.8 grams per pound of body weight. Although yams do not contribute significantly to your daily protein requirements, 1 cup offers over 2 grams of protein.