Which of the following is NOT a type of dietary fiber?

The correct answer is based on understanding the classifications of dietary fiber. Dietary fiber is primarily categorized into two main types: soluble and insoluble. Soluble fiber dissolves in water and can be found in foods like oats, beans, and fruits. It plays a key role in lowering cholesterol and stabilizing blood sugar levels. Insoluble fiber does not dissolve in water and is typically found in whole grains, vegetables, and nuts, aiding in digestive health by promoting regular bowel movements.

Resistant fiber is a lesser-known category, often considered a subtype of soluble fiber. It resists digestion in the small intestine and can be fermented in the large intestine, contributing to gut health.

Fermentable fiber, while a characteristic of many types of dietary fiber (including some soluble and resistant fibers), is not a stand-alone type of dietary fiber. It refers to the ability of certain fibers to undergo fermentation in the gut by beneficial bacteria, leading to health benefits such as improved gut microbiome and production of short-chain fatty acids.

In summary, the classifications of dietary fiber include both soluble and insoluble types, with resistant fiber being an additional category. Fermentable is not categorized as a distinct type of dietary fiber, which makes it the correct choice for the question