If you constantly feel tired, struggle to stay alert during the day or depend on several cups of coffee to get through work, your diet may deserve a closer look. While poor sleep, stress, long working hours and an inactive lifestyle are common causes of fatigue, inadequate nutrition can also contribute to low energy. One simple food that can add important nutrients to your diet is black sesame seeds, commonly known as kala til. A small serving of black sesame seeds in a balanced diet provides several nutrients involved in energy metabolism.