What is the main function of proteins in the body?

The main function of proteins in the body is to support the structural integrity and function of cells. Proteins are essential macromolecules made up of amino acids, which serve as building blocks for various tissues, including muscles, skin, and organs. They play a critical role in maintaining the architecture of cells and tissues, providing support and shape, which is vital for overall health.

Additionally, proteins are involved in numerous biological processes, including enzyme activity, hormone production, and immune responses. They facilitate cell signaling and communication, ensuring that cells can perform their specific functions effectively. By participating in the structure and function of cells, proteins help maintain homeostasis and enable growth, repair, and overall physiological efficiency.

While other options present important aspects of nutrition and physiology, they do not encompass the primary structural role that proteins play in the body. Proteins are not primarily energy sources or reservoirs for excess nutrients, nor do they directly facilitate insulin sensitivity; rather, their foundational role in cellular structure and function is critical for life.