Which characteristic describes insoluble dietary fibers?

Insoluble dietary fibers are primarily known for their ability to provide structure and protection for plants. This type of fiber does not dissolve in water, which is a key distinguishing feature from soluble fibers. Insoluble fiber contributes to the structural integrity of plant cell walls, helping them maintain shape and resist external stressors. This structural role is essential for the plant's overall function and health.

In contrast, the other characteristics are associated with soluble fibers. For instance, soluble fibers are known to dissolve in fluids, help lower cholesterol levels by binding to bile acids, and enhance feelings of fullness, which contributes to increased satiety. Understanding these distinctions is important when studying the roles of different types of dietary fibers in nutrition and health.