Primary macronutrient for growth and maintenance of our body's structural parts (including muscle). Cannot be stored, so must be replenished through diet. (1 gram = 4 calories).
Protein powders are useful to supplement your diet with a high quality protein without consuming the saturated fats that frequently accompany whole foods that are high in protein. Some people prefer to eat foods that are high in carbohydrates, so consuming protein drinks with meals allows them to continue to eat their preferred foods while getting the protein their body needs. Protein powder is also excellent for use in recipes to make Zone diet, low carbohydrate diet, ketogenic diet, or just high protein meals.