What is the primary role of carbohydrates in the human diet?

The primary role of carbohydrates in the human diet is to provide energy and serve as a major fuel source. Carbohydrates break down into glucose, which is the body's preferred source of energy for various functions, including physical activity and the maintenance of bodily functions like digestion and brain activity. This is crucial because the body relies on this readily available energy to perform efficiently throughout the day.

Contrastingly, while supporting immune function and tissue repair is vital for the body, that role is primarily associated with proteins and certain micronutrients. Storing vitamins and minerals is a key function of certain nutrients, particularly fats and specific cells in the body, rather than carbohydrates. Lastly, enzymes for digestion are proteins that facilitate chemical reactions but are not carbohydrates themselves. This further highlights the unique and essential role carbohydrates play in providing immediate energy, making the first choice the most accurate answer.