NANP Board Practice Exam

Which type of fiber does not absorb or dissolve in water?

1. Insoluble fiber

2. Resistant fiber

3. Simple fiber

4. Soluble fiber

The correct answer is: Insoluble fiber

Insoluble fiber does not absorb or dissolve in water because it has a different chemical makeup compared to soluble fiber. Insoluble fiber is made up of large, complex carbohydrates that cannot dissolve in water. This means that it passes through the digestive system largely intact, providing benefits such as promoting regular bowel movements and aiding in digestion. On the other hand, resistant fiber refers to a type of soluble fiber that resists digestion until it reaches the large intestine, where it is then fermented by bacteria. Simple fiber may refer to either soluble or insoluble fiber, but it does not provide enough context to determine which type it is. Soluble fiber, on the other hand, is different from insoluble fiber as it can dissolve in water and forms a gel-like substance in the digestive system, potentially aiding in lowering cholesterol levels and regulating blood sugar. Therefore, insoluble fiber is the only option that does not absorb or dissolve in water, making it the correct answer.