Macronutrients refer to the three essential nutrients required in large quantities by the body: carbohydrates, proteins, and fats. Each macronutrient serves distinct roles in providing energy, supporting bodily functions, and promoting overall health. Carbohydrates are the primary energy source, proteins are crucial for muscle repair and growth, and fats play roles in hormone production and nutrient absorption. Balancing these macronutrients is key to meeting nutritional needs and supporting optimal health and performance.