Which macronutrient is primarily responsible for structure and repair in the body?

Proteins are the primary macronutrient responsible for structure and repair in the body. They are made up of amino acids, which are the building blocks necessary for the growth and maintenance of tissues. Proteins play a critical role in building muscle, repairing tissues after injury, synthesizing enzymes, and producing various hormones that regulate body functions.

In addition to their structural roles, proteins are essential for immune function, as antibodies are composed of proteins that help defend the body against pathogens. The body's need for protein increases during periods of growth, recovery from illness, or injury, highlighting its importance in tissue repair and structural integrity.

While carbohydrates and fats serve important roles in providing energy and support for bodily processes, they do not primarily contribute to structure and repair. Vitamins, although crucial for various biochemical functions in the body, are micronutrients and do not directly provide the structural components needed for tissue repair. Thus, proteins stand out as the key macronutrient in this context.