Is insoluble fiber only partially digestible, and what is completely digestible?

Insoluble fiber is indeed only partially digestible. This type of fiber is primarily found in foods such as whole grains, nuts, and vegetables. Its main role in the digestive system is to add bulk to stool and facilitate bowel movements, rather than being broken down for nutrients.

The correct statement is that soluble fiber is completely digestible to some extent because it can be fermented by bacteria in the large intestine, resulting in the production of short-chain fatty acids that can be utilized by the body for energy. Soluble fiber is found in foods like oats, beans, and fruits, contributing to health benefits such as improved cholesterol levels and blood sugar control.

Other options reference proteins and carbohydrates, which are macronutrients where complete digestion occurs, as they provide the building blocks (amino acids) and energy sources (glucose) needed by the body. However, soluble fiber remains the focus when discussing digestion related to types of fiber in this context. Thus, identifying soluble fiber as the component that is completely digestible aligns with the characteristics of fiber types and their roles in nutrition.