What is the primary function of carbohydrates in the diet?

The primary function of carbohydrates in the diet is to serve as the body's main source of energy. Carbohydrates are broken down into glucose, which is utilized by the body's cells for energy. This energy is crucial for maintaining bodily functions and supporting activities, particularly those that require quick bursts of energy, such as high-intensity exercise.

While carbohydrates are an essential part of a balanced diet, they play a distinct role compared to proteins or fats. For instance, proteins are more closely associated with muscle repair and growth, and fats provide essential fatty acids that the body cannot produce on its own. Additionally, while carbohydrates can influence digestion and satiety, their primary and most vital role is energy provision. Therefore, the emphasis is on their function as a primary energy source, making that the correct answer.