Which nutrient is primarily responsible for growth and repair of body tissues?

The nutrient primarily responsible for the growth and repair of body tissues is protein. Proteins are large, complex molecules made up of amino acids, which are essential for building and repairing tissues such as muscles, skin, organs, and other bodily structures. They play a critical role in various physiological processes, including hormone production, immune function, and the transportation of nutrients throughout the body.

During periods of growth, such as childhood and adolescence, or after injury or surgery, the body's demand for protein increases to support tissue synthesis and healing. Proteins act as the building blocks for cells and tissues, making them vital for maintaining overall health and physical recovery. This characteristic uniquely positions protein as the key nutrient involved in the growth and repair processes compared to carbohydrates, fats, and vitamins, which serve different roles in the body, such as providing energy or supporting metabolic functions.