Final answer:
Dietary fibers are classified by properties including susceptibility to fermentation, solubility, and water-holding capacity but not by chain length. The term 'chain length' is not commonly used in the classification of dietary fibers.
Step-by-step explanation:
Dietary fibers are classified by several properties, including susceptibility to fermentation, solubility, and water-holding capacity. However, they are not classified based on chain length. Fibers were initially categorized as soluble or insoluble, but this classification has evolved as the nutrition community now favors terms that better describe fibers' functionalities, such as fermentable, nonfermentable, viscous, and nonviscous. Soluble fibers, which dissolve in water, can become viscous and may be fermented, leading to physiological benefits like an extended feeling of fullness and the production of short-chain fatty acids. Insoluble fibers, on the other hand, do not dissolve in water and provide bulk to the diet, aiding in regularity and easing defecation.