Which type of nutrient does the body use to build and maintain its cells and tissues?

The body primarily uses proteins to build and maintain its cells and tissues. Proteins are essential macromolecules made up of amino acids, which are the building blocks that play a crucial role in the structure and function of cells. They are involved in creating enzymes, hormones, and other important chemical messengers in the body. Additionally, proteins are vital for repairing tissues, growing muscle, and supporting the immune system.

While carbohydrates are a primary source of energy and fats are important for energy storage and cell membrane structure, they do not directly contribute to the building of tissues in the same way that proteins do. Vitamins, though essential for various biochemical functions in the body, are not structural components. Thus, proteins stand out as the nutrient specifically responsible for the development and maintenance of bodily cells and tissues.