What is dietary fiber and why is it important? Everything you don't know

What is dietary fiber and why is it important?

Medically reviewed and approved by Nataniel Josue M.D.

What is dietary fiber? Dietary fiber is a fundamental substance for human nutrition. In the past, scientists believed that our organism could not digest it because it did not have the necessary enzymes to degrade it. Subsequently, it is fundamental to our diet. 

We can define dietary fiber as the components mostly in the cell wall of vegetables and are resistant to the human intestinal tract's digestion. Fiber is composed of pectin, lignin, cellulose, hemicelluloses, alginates, carrageenan, mucilages, algae polysaccharides, and gums as guar and carob.

According to Diet and Health, fiber has a significant protective role in the stomach, colon, rectum, and female gynecological cancers. It also helps protect against coronary heart disease, hypertension, diabetes, diverticulosis, and gallstones.

That is because it has countless advantages for our body, such as improving intestinal transit and minimizing sugar and cholesterol absorption. That makes preventing constipation, hemorrhoids, diabetes, and decreases the risk of contracting cardiovascular diseases.

The fiber is something fundamental for the correct operation of our organism. It has many advantages, such as a lower risk of cardiovascular diseases.

It also has a laxative effect necessary for our digestive tract and our body's correct functioning in general.

Concentrate on the intake of dietary fiber for a better diet. Lose more weight and feel healthier with a daily dose of fiber.

Table of Contents

What food is high in dietary fiber?

According to a study by RR Selvendran, dietary fiber components vary according to maturity and the part of the plant consumed. The foods but rich in fiber are the integral cereals, vegetables, legumes, fruits, dry fruits, seeds, the bran of the grains, and the berries.

Why is dietary fiber important?

According to a study published in Nutrients, fiber's habitual consumption contributes to reducing obesity, diabetes, cancer, and coronary diseases. The rich diets in fiber usually require more ingestion and mastication, increasing the satiety; besides, they reduce foods' gross energy.

What foods are highest in fiber?

Now I will give you a table with foods rich in fiber with their soluble and indissoluble amounts of fiber.

Food Indissoluble Soluble Total
Oats 6.5 3.8 10.3
Rice (dry) 1.0 0.3 1.3
Rice (Boiled) 0 0.7 0.7
Wheat germ 12.9 1.1 14.0
Wheat (whole grain) 10.2 2.3 12.6
Corn - - 13.4
White beans 13.4 4.3 17.7
Green beans 1.4 0.5 1.9
Soy beans - - 15
Peas 3.2 0.3 3.5
Lentils 10.3 0.1 11.4
Potato 1.0 0.3 3.5
Pumpkin 13.5 3.1 16.6
Beet 5.4 2.4 7.8
Fenugreek leaves 4.2 0.7 4.9
Spinach 2.1 0.5 2.6
Turnip 1.5 0.5 2.0
Tomato 0.8 0.4 1.2
Onion 2.2 0 2.2
Eggplant 5.3 1.3 6.6
Cucumber 0.5 0.1 0.6
Cauliflower 1.1 0.7 1.8
Celery 1.0 0.5 1.5
Carrot 2.3 0.2 2.5
Broccoli 3.0 0.29 3.29
Apple 1.8 0.2 2.0
Kiwi 2.61 0.8 3.39
Mango 1.06 0.74 1.8
Pineapple 1.1 0.1 1.2
Pomegranate 0.49 0.11 0.6
Watermelon 0.3 0.2 0.5
Grapes 0.7 0.5 1.2
Oranges 0.7 1.1 1.8
Plums 0.7 0.5 1.6
Strawberry  1.3 0.9 2.2
Banana 1.2 0.5 1.7
Peach 1.0 0.9 1.9
Pear 2.0 1.0 3.0
Almond 10.1 1.1 11.2
Coconut 8.5 0.5 9.0
Peanut 7.5 0.5 8.0
Cashew nut - - 6.0

Source Science Direct

What is a dietary fiber made of?

dietary fiber

Lignin substances linked to the Lignin complex and NSP 

  • Waxes.
  • Cutting.
  • Phytate.
  • Saponins.
  • Suberin.
  • Tannin.

Carbohydrate analogs.

  • Resistant starches.
  • Synthesized carbohydrate compounds
  • Resistant potato dextrins.
  • Indigestible dextrins.
  • Hydroxypropyl methylcellulose.
  • Resistant maltodextrins.
  • Methylcellulose.

Oligosaccharides and Polysaccharides without starch

  • Arabinogalactans.
  • Arabinoxylans
  • Dinner.
  • Cellulose.
  • Galactooligosaccharides.
  • Hemicellulose.
  • Inulin.
  • Mucilages.
  • Oligofructans.
  • Pectins.
  • Polyfructose.

Source, Nutrients

Dietary fiber benefits

  • It helps to reduce the fluctuation of the blood sugar level.
  • It decreases the likelihood of heart disease.
  • Fiber helps decrease appetite.
  • It helps prevent the symptoms or onset of diabetes or metabolic syndrome
  • It prevents colorectal cancer.
  • Fiber helps with regularity.
  • It relieves constipation.

Dietary fiber intake recommendations

According to the American Dietetic Association Journal, dietary fiber's recommended intake should be 14 g per 1000 kcal or 25 g for an adult woman and 38 g for an adult man. These are the amounts that, according to all reports, help prevent diseases such as cancer, heart conditions, and diabetes.

These are the recommended amounts; the U.S. Institute of Medicine recommends taking 14g of fiber per 1000 calories, regardless of your age.

You already know that to lose weight, you must combine a healthy diet and exercise. If you want more information on how to lose weight, click here.

That said, certain foods are an essential part of the diet. Fiber is a vegetable component that helps satisfy our appetite and is also very beneficial to our health.

You may be interested in "What foods should you eat every day?"

What are the 2 types of dietary fiber?

There are two types of fiber: soluble and insoluble.

Soluble Fiber

Soluble fiber dissolves in water, forming a gel in the stomach. The gelatinous substance that is produced slows down the speed at which food moves from the stomach to the small intestine.

Oatmeal, nuts, beans, lentils, and fruits contain this healthy version. When you cook oat flour, it becomes sticky, which is the presence of soluble fiber.

Indissoluble Fiber

The indissoluble fiber does the opposite - it moves directly through the gastrointestinal tract, supporting regular digestive movements.

It is responsible for an excellent intestinal tract.  That is because our digestive system has no bacteria to break it down.

Also, this causes it to have a cleansing effect on the entire digestive system. Foods of this type are whole wheat, whole grains, legumes, and vegetables.

Dietary fiber properties

  • It helps to feel satiated.
  • It delays the absorption of glucose.
  • Fiber attracts water by turning into a gel during the digestive process.
  • It helps regulate blood pressure.
  • It gives more volume to the feces.
  • Fiber stimulates the production of intestinal fermentation of short-chain fatty acids.
  • It contributes to the balance of the intestinal pH.
  • It contributes to accelerating the passage of food through the entire digestive system.

Fiber will not only help you lose weight. Studies have shown that incorporating fiber into your daily diet can prevent heart disease and reduce cholesterol.

Soluble fiber, specifically, fiber influences the rate of fat absorption when it comes to lowering cholesterol - reducing the amount of fat present in the blood.

An attractive muscle-building component is a dietary fiber lowers blood glucose levels - preventing the muscle from having excess sugar.

Tip: keep fiber-rich foods away from your post-workout meal because that's the only time of day you want a peak of insulin.

When you are trying to make your progress, thanks to protein (fat loss and muscle gain) not being lost, fiber can prevent unwanted protein expenditure.

Protein takes some time to be synthesized in your body, producing a thermal effect. When the protein is broken down, nitrogen is what's left. A positive nitrogen balance in the body means only one thing: gas.

Suppose we follow a low-carb diet mixed with a ton of protein; when cut will only create constipation. Elevated levels of post-training insulin are an aid in making more significant muscle gains.


Now that you are aware of fiber's benefits, how much should we consume every day?

The national recommendations are 30 to 38 grams per day for men under 50 and 25 grams per day for women under 50.

A general guideline to follow is to consume 14 grams of fiber for each 1,000 ingested calories.

The key to eating fibrous foods during the day is to eat a high-fiber food with every meal.