A dietary macronutrient is one that provides calories and energy to our body. These are essential nutrients required by our bodies in large quantities, and they include carbohydrates, proteins, and fats. Carbohydrates provide 4 kcal/gm, protein provides 4 kcal/gm, and fat provides 9 kcal/gm of energy. These macronutrients are necessary for growth, development, and maintenance of body tissues, as well as providing the required amount of calories to sustain life.