What is the main function of proteins in the body?

The primary function of proteins in the body is to build and repair tissues. Proteins are composed of amino acids, which serve as the building blocks for various body structures, including muscles, skin, organs, and enzymes. When the body requires new tissue growth, such as during childhood, after injury, or through intense physical activity, proteins play a crucial role in the formation of new cells and the repair of damaged ones.

Some proteins also have regulatory functions in the body, acting as enzymes that catalyze biochemical reactions, hormones that regulate physiological processes, and antibodies that help in immune response. While proteins can provide energy, this is not their main function. Instead, carbohydrates and fats are generally the body's primary energy sources. Additionally, proteins do not facilitate digestion directly, nor do they serve as a significant nutrient storage form, which makes their role in tissue building and repair paramount among their functions.