How Different Types of Dietary Fiber Affect Your Body?

types of dietary fiber

Dietary fibers can affect multiple aspects of human health. The indigestible part of different foods is fiber, and it promotes good gut health. Dietary fibers help in losing weight by keeping you fuller for longer times. Most people think all dietary fibers are the same, but the truth is the opposite. There are several types of dietary fiber, and all types are not the same regarding their functioning.

Some fibers are good for digestive health while some may ruin it. So, it is important to understand various types of dietary fiber and their role in the human body.

What is fiber?

Fiber is an indigestible part of various food items we eat daily like fruits, cereals, legumes, whole grains, seeds, and vegetables. It is a diverse group that belongs to carbohydrates.

The human body lacks the enzymes that are required for the breakdown of fiber. As a result, it passes out of the body unchanged.

The human body needs fiber for various functions. The recommended amount for men is 38 grams, while for women is 25 grams. Most people do not get the recommended amount of fiber and face different health problems.

Risks associated with low fiber intake

In western countries, bowel cancer and diabetes are common due to low intake of fiber. There are plenty of health risks associated with low intake of fiber like:

  • Constipation
  • IBS (irritable bowel movement)
  • Breast cancer
  • Heart diseases
  • Hemorrhoids
  • Colon cancer
  • Metabolic syndrome
  • High cholesterol level
  • Diverticulitis

Health benefits of fiber

Fiber is important for overall digestive health. The human digestive system mixes the food, breaks it down, and passes it out through the body. During this process, fiber plays an important role and helps in bulking up the stool. Furthermore, fiber plays a crucial role in various other processes:

  • It helps in lowering the blood cholesterol level
  • Maintains and helps in losing weight
  • Keeps the blood glucose level stable
  • Promotes gut-friendly bacteria and improves overall digestive health
  • Minimizes the risk of cardiovascular diseases by lowering cholesterol levels and decreasing the fat absorption
  • Reduces the risk of several other chronic conditions like colon cancer, heart diseases, and diverticulitis.

Types of dietary fiber

There are many types of dietary fiber, and they can be classified in different ways that make it confusing.

However, there are the following main types of dietary fiber:

  • Soluble vs. insoluble fiber
  • Viscous vs. non-viscous fiber
  • Fermentable fiber
  • Resistant starches

Soluble vs. insoluble fiber

The fiber is classified based on its ability to dissolve in water. It includes soluble fiber and insoluble fiber. Plants are the main source of both types of fiber. They contain these fibers in varying amounts.

Soluble fiber, as the name indicates is soluble in water. This fiber forms a gel-like substance that is absorbed by the blood. It helps in improving metabolic health and prevents blood glucose spikes. It includes psyllium, pectin, mucilage, gums, and beta-glucans.

Following are the good sources of soluble fiber:

  • Fruits
  • Vegetables
  • Flaxseed and psyllium husk
  • Legumes and beans
  • Soy products

Insoluble fiber does not dissolve in water. It remains intact and usually passes through the body unchanged. It helps in bulking up the stool. Insoluble fiber speeds up the movements of foods and water through the digestive tract. It includes lignin, hemicellulose, and cellulose. These three types perform structural roles in plants. The human body lacks the enzymes that are required to break down these enzymes.

Following are the good sources of insoluble fiber:

  • Bran
  • Nuts
  • Seeds
  • Wholegrains
  • Dried beans
  • The skin of fruits and vegetables

Viscous vs. non-viscous fiber

Viscosity refers to the thickness of the fiber. Viscous fibers are a type of soluble fiber. They form a gel-like substance when dissolved in water.

The most common types of viscous fiber include psyllium, guar gum, and pectin. Foods that are a rich source of this type of dietary fiber include Brussels sprouts, oats, flax seeds, and legumes.

This fiber makes a thick substance after dissolving into the water and settles in the gut. Due to its viscous nature, it sits in the gut for many hours and gives a feeling of fullness. It reduces the appetite and significantly helps in losing weight. That is the reason soluble fiber promotes weight loss and improves gut health.

It doesn’t mean every type of fiber works this way. Several studies suggest only soluble and viscous fiber helps in reducing appetite, limiting food intake, and promoting weight loss.

Non-viscous fibers include wheat dextrin, acacia, inulin, and partially hydrolyzed guar gum.

Fermentable fiber

Fermentable fiber is also called prebiotic fiber. It is a soluble fiber that dissolves into the water. Some insoluble fermentable fibers also exist.

Fermentable fibers are fermented into gases in the large intestine. The large intestine or colon of the human body has trillions of bacteria. These bacteria are gut-friendly and perform various functions to support good gut health.

Gut-friendly bacteria are involved in managing weight and blood sugar levels. Several other processes like brain functioning, immunity, and mental health are also related to these bacteria. Gut-friendly bacteria are crucial to maintaining human health. These fibers also play a role in the absorption of minerals, especially calcium.

Insoluble fiber is not digested by the human body. So it reaches the large intestine. The gut-friendly bacteria use them and ferment to make gases. They use these fibers to fulfill their energy needs.

Besides fulfilling their energy needs, bacteria produce short-chain fatty acids. These fatty acids are linked with the various process of the body.

In this way, the gut-friendly bacteria reside there in a symbiotic relationship where the human body provides the energy while bacteria ferment the fiber to support various processes.

Gas is the byproduct of all this fermentation process. This is why many people who are not used to fermentable fiber foods experience gas (flatulence) in their stomachs. It causes discomfort.

Pectin, inulin, guar gum, and beta-glucans are examples of fermentable fibers. Beans and legumes are rich sources of fermentable fibers. Regular intake of fermentable fiber prevents several chronic conditions while insufficient fiber intake may cause constipation.

Resistant starch

Starches need no introduction. They are the most common type of carbohydrates that are found in our daily diet.

Grains, potatoes, bananas, oats, legumes, and several other foods contain resistant starches. Starches also belong to insoluble and fermentable fibers. They cannot be digested, so they pass out the body without changing.

Starches play a vital role in improving various health conditions. They reduce the appetite, keep you full for longer, reduce the blood sugar level, improve the digestive system and insulin sensitivity.

How to add more fiber to your diet?

Fiber is an essential part of a routine diet. You must add the recommended amount of fiber to your daily diet to get the maximum health benefits. Small changes in your routine will help you add more fiber to your meals.

  • Eat cereals in breakfast like wheat and oats.
  • Instead of eating processed or refined products – opt for whole wheat grains, brown rice, multigrain bread, and other products.
  • Add more beans, grains, and legumes to your daily diet by adding them to your soups, salads, appetizers, and side dishes.
  • Snack on fruits, vegetables, salads, nuts, and dried fruits.
  • Always add a portion of fruits and vegetables to your breakfast, lunch, and dinner plates.
  • Make spreads with lentils, beans, and pulses.
  • If you are not meeting your daily fiber requirement, add fiber supplements to keep your digestive health stable.


Fibers are the most diverse group of carbohydrates, and there are many types of dietary fiber. They can be soluble, insoluble, fermentable, viscous, and resistant starch.

Almost all forms of fiber are healthy and provide various health benefits. Taking a low amount of fiber is associated with different health risks.

Fruits, vegetables, legumes, beans, lentils, nuts, and seeds are good sources of fiber. Add plenty of these foods to your diet to meet your daily fiber requirement.

Spread the love