High Fiber Diet

What is Dietary Fiber? Dietary fiber or roughage is that part of a plant that is indigestible. We can get dietary fiber from plants, bushes, vines, and trees. It consists of carbohydrates in the form of cellulose, hemicellulose, and lignin and is considered essential for keeping our gut healthy.1

Types of Fiber

There are different types of fiber available, but the most important types are:

Insoluble fiber

Insoluble fibers do not dissolve in water; neither are they fermented by the bacteria colonizing the gut. As it does not dissolve in water, its main property is to retain maximum water that helps produce a larger, bulkier, and more regular bowel movement. It can prevent anyone from having constipation, haemorrhoids, and diverticulosis. Its sources are:

  • Whole grain wheat (brown rice, oats)
  • Seeds and nuts
  • Green vegetables such as green beans and cauliflower
  • Tomatoes and kiwi

Soluble fiber

As the name indicates, soluble fiber can dissolve in water and is used by colon bacteria as their food source.2 Colon bacteria are essential for the normal functioning of the gut. Its main sources are:

  • Barley and rye
  • Fruits such as apples, bananas, and pears
  • Carrots and broccoli
  • Peas and soybeans
  • Root vegetables

Prebiotic soluble fiber

These fibers are fermented by bacteria present in the colon and produce further benefits to the gut. These fibers are also known as inulin or fructan. They are present in:

  • Onions
  • Garlic
  • Yams
  • Leeks
  • Agave
  • Asparagus

Benefits of a High Fiber Diet

There are certain benefits of eating a high-fiber diet regularly. Some of the main benefits are:3

Regular Bowel Movement

Fiber helps promote a softer and regular bowel pattern that is helpful for patients with constipation, haemorrhoids, and diverticulosis.

Lowering Cholesterol

When used regularly, fiber plays a vital role in reducing body cholesterol, especially soluble fibers.

Prevents Cancer and Colon Polyps

This fact is not clear yet, but is supported by research that regular use of fiber helps in preventing colon polyps and cancer by excreting carcinogenic substances through stool.

Lowering Blood Sugar

Soluble fibers in the form of legumes slow down the absorption of sugar in the blood and, in this way, reduce blood sugar.

Weight Loss

Fiber gives a feeling of satiety earlier than other foods; hence, it helps in reducing weight.

Maintains Colon Wall Integrity

Fibers maintain a balance between good and bad bacteria and are involved in the proper functioning of the gut.

The Amount of Fiber Required for a Healthy Body

Under Age 50                Over Age 50

Men         38 grams            30 grams

Women    25 grams            21 grams

Which fibers are best for the gut?

As discussed earlier, healthy fibers are present in plants in the form of whole grains, fruits, and vegetables.4

Whole Grain

Use whole grains for better health. Wheat, oats, barley, wild or brown rice, bulgur, corn, millet, and rye are rich sources of whole grains and should be used frequently.


Consumption of fruits should be increased if you want to increase the fiber in your diet because fruits like apples, pears, and bananas contain many soluble and insoluble fibers. Eat the skins of certain fruits, too, such as apples, to multiply fiber intake.


Eat a variety of vegetables for lunch and dinner to increase fiber intake.

Fiber Supplements

These can also boost the fiber levels in the body if you are deficient. You may consider:

  • Psyllium
  • Methyl Cellulose
  • Inulin


  1. Barber TM, Kabisch S, Pfeiffer AFH, Weickert MO. The Health Benefits of Dietary Fibre. Nutrients. 2020;12(10):1-17. doi:10.3390/NU12103209
  2. Salleh SN, Fairus AAH, Zahary MN, Raj NB, Jalil AMM. Unravelling the Effects of Soluble Dietary Fibre Supplementation on Energy Intake and Perceived Satiety in Healthy Adults: Evidence from Systematic Review and Meta-Analysis of Randomised-Controlled Trials. Foods. 2019;8(1). doi:10.3390/FOODS8010015
  3. Huber JT, Riddlesperger K. High Fiber Diet. Eat Posit. Published online May 8, 2022:49-64. doi:10.4324/9781315043388-12
  4. Dietary Fiber - Diet and Health - NCBI Bookshelf. Accessed June 9, 2022. https://www.ncbi.nlm.nih.gov/books/NBK218764/

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