Which nutrient is essential for building muscle and repairing and replacing cells?

• A. Proteins
• B. Carbohydrates
• C. Fats
• D. Vitamins

Answer: (A)

Proteins are the building blocks your body uses to create and repair tissue. When you train, muscles incur small tears that need to be repaired. The body uses amino acids—the components of proteins—to synthesize new muscle proteins and other structural proteins, helping muscles grow stronger and supporting the repair of all body cells. Adequate protein intake ensures a positive balance between muscle protein synthesis and breakdown, which is essential for building muscle.

Carbohydrates and fats are important for energy and overall metabolism, and vitamins support these processes, but they don’t provide the primary building blocks for muscle tissue. Therefore, for building muscle and repairing cells, proteins are the key nutrient. Aim for enough total protein daily, spread across meals, with high-quality sources that supply all essential amino acids. A common guideline for active individuals is about 1.6–2.2 g of protein per kilogram of body weight per day.