What is a common function of complex carbohydrates?

Complex carbohydrates play a crucial role in storing energy for long-term use. These carbohydrates are made up of long chains of sugar molecules, which means they are digested more slowly than simple carbohydrates. This slow digestion provides a steady release of glucose into the bloodstream, which helps maintain energy levels over an extended period. Foods high in complex carbohydrates, such as whole grains, legumes, and vegetables, not only contribute to energy storage but also provide essential nutrients and fiber, which are beneficial for overall health.

In contrast, the other options represent functions that are typically associated with different types of nutrients or processes. For instance, quick energy is primarily provided by simple carbohydrates, which can be rapidly broken down for immediate energy. Supporting cell structure often relates to other macromolecules, such as proteins or certain lipids, rather than complex carbohydrates. Enhancing flavor is similarly not a function of complex carbohydrates, as this is more related to fats, sugars, or spices used in food.