What is a key function of proteins in our diet?

Proteins play a vital role in the body primarily through their function in building and repairing tissues. This includes muscle tissue, which is essential for physical performance, maintenance of body structure, and recovery from injuries. Proteins are made up of amino acids, which serve as the building blocks that repair tissues that may be damaged during exercise or daily activities.

While proteins can provide energy, especially if carbohydrates and fats are not available, they are not the body's primary energy source like carbohydrates and fats are. Thus, while energy provision is a function of proteins, it is not their key role.

Regulating body temperature is primarily managed by the body’s systems, such as blood flow and evaporative cooling through sweat, and is not a direct function of proteins in the diet.

Supporting hormone production is another important role of proteins; however, it is often secondary to their primary function of tissue repair and building. Hormones can be composed of proteins or derived from amino acids, but focusing solely on hormone production does not encompass the broader and more fundamental role of protein in tissue health and recovery.

Thus, the key function of proteins in our diet is definitively their role in building and repairing tissues, making that the most accurate choice in this context.