Dietary Fiber – Benefits and Sources

We know that we need to eat healthy food and live a healthy lifestyle. With two-thirds of the US population either obese or overweight, we’re certainly not following the dietary guidelines we should be.

Even when we know it’s right, like eating salads instead of burgers and super sized fries from a fast food establishment, we still eat them.

That’s the case for fiber in our diets. We don’t eat nearly enough. We know it’s healthy, we hear it all of the time; but we aren’t consuming enough, and we’re worse off because of it

This article will cover what is fiber, how it helps the digestive process, and fiber’s benefits. 

Fiber and The Digestion Process

Fiber helps the body properly eliminate waste products from the digestive system. After your body absorbs all the nutrients from the food you eat, it passes some of the food and its nutrients through your digestive system and into your large intestine where it gets converted into stools.

Your body absorbs fluid through your colon. What’s left is the shaped stool to be eliminated through a bowel movement. Too little fiber can result in the body absorbing too much of the fluid in the colon, leaving the stool hard and difficult to pass.

Undigested fiber in the colon helps to absorb fluids, which forms a softer, bulkier, and easier-to-pass stool.

Stools with ample fluids will move more easily through the colon, helped by gentle muscle contractions. If you don’t drink enough water, your stools will shrink and become hard.

Then, your colon muscles won’t be able to grip the stool and move them towards the rectum for excretion. Enough of these shrunken, hard stools can result in constipation and even possible intestinal blockages.

With age, your muscles contract less strongly and so moving the stool becomes harder. Stool movements are then required to use “straining” if the muscles involved are used to help eliminate.

Straining can put pressure on the abdominal wall and pelvic floor. That can result in anal fissures, constipation, digestive diseases, hemorrhoids, hernias, and varicose veins. Eliminating straining eliminates the ailments that go with them.

Types and Sources Of Fiber

Dietary Fiber Benefits and Sources

There are two types of fiber: insoluble and soluble fiber.

Insoluble Fiber

Insoluble fibers don’t dissolve in water and will increase the bulk and softness of the stool, which makes them easier to pass. It’s especially helpful for people who struggle with irregularity and constipation.

Insoluble fiber passes through the intestines without being digested. It prevents constipation by removing toxins from the colon and balances the acidity in the intestine.

Soluble Fiber

Soluble fibers dissolve when they come into contact with water and form a gel. This substance coats the inside of the colon so that it’s easier for stool to pass through. It also helps to lower glucose and cholesterol levels.

Soluble fiber binds with fatty acids, lowering the total cholesterol level and reducing the risk of cardiovascular disease. It also slows down sugar absorption which helps to regulate blood glucose levels in people with diabetes.

Fiber Supplements

Fiber supplements are a good way to get some of your daily fiber intake. Fiber supplements will help you to obtain the recommended 25-30 grams of fiber per day, but they shouldn’t be your only source of dietary fiber. Fiber supplements will be most helpful during times of travel or when too busy to eat a healthy meal.

Fiber supplements need to be taken daily to be effective. It should not be taken only when constipation or any other digestive ailment occurs. You won’t see results immediately.

Fiber builds up in your digestive tract which makes stool softer and easier to pass. You will start to notice the positive effects of your increased fiber intake within a few weeks.

Read more about Fiber Supplements for IBS.

Benefits of Fiber

Fiber is a crucial component in relieving symptoms of common digestive conditions, including:

Fiber is best known as a natural remedy for relieving chronic constipation, but fiber also helps lower your risk of developing diabetes and heart disease. Fiber can also help you lose weight, but it won’t magically make you thinner.

These are some of the top fiber benefits: 

  • Keeps us feeling full
  • Reduces the risk of blood glucose spikes
  • Reduces food cravings
  • Prevents constipation
  • Makes it easier to lose weight
  • Reduces the risk of heart disease
  • Prevents diarrhea and loose stool
  • Reduces bloating
  • Improves normal bowel transit time and function

Heart Disease and Fiber

Heart disease is the leading cause of death for both men and women in America. Cholesterol is a waxy substance found in the blood. High levels of cholesterol in the arteries can lead to heart disease.

This cholesterol buildup can cause arteries and blood vessels to become narrow, hard and blocked. A full blockage can result in a heart attack.

Soluble fiber is associated with lower cholesterol levels. Lower cholesterol levels mean less clogging of the arteries, which means a lower risk for heart diseases.

A Harvard study found that a high dietary fiber intake was associated with a 40% lower risk for developing heart disease.

Type II Diabetes and Fiber

Type II diabetes is the most common type of diabetes. It is characterized by sustained increased sugar levels in the blood. If the body cannot produce enough insulin to lower the blood sugar level, then type II diabetes develops.

Foods with a high glycemic index (GI) increase the risk of developing Type II diabetes. These foods raise blood sugar levels quickly, and the body can’t produce enough insulin to lower them.

Foods that have a high glycemic index are also very low on fiber. Examples may include white bread, sugar, refined cereals, white spaghetti, and white rice.

Foods that are high in fiber also have a lower glycemic index and can help lower your risk of developing Type 2 Diabetes. These foods include beans, oatmeal, whole grains, brown rice, whole fruits, and whole wheat bread.

According to a study conducted by Harvard Medical students, diets containing a lot of high glycemic index foods increased the risk of developing Type 2 diabetes by almost double.

Fiber and Weight Loss

Fiber is also considered one of the key ingredients for weight loss.

It’s a fact: the brain is 10 minutes slower than the stomach, so we don’t register that our stomachs are full until 10 minutes later. Fiber-rich foods generally take longer to eat than low-fiber foods. This extra chewing time gives our brains a chance to catch up to our bellies, so we don’t overeat.

Fiber-rich foods absorb a lot of fluid. “Eating” this extra water helps you feel fuller for a long time. Reducing overeating and unnecessary snacking helps lead to weight loss.

A high-fiber diet plays an important role in weight loss, but it is always important to include regular exercise to help you reach your weight-loss goals.

Also learn more about Prebiotics and Weight Loss.

How to Increase Fiber in Your Life

The FDA recommends that we should be getting at least 25-30 grams of dietary fiber every day; the average American only get 10-15 grams.

You should get 90% of your fiber from the foods that you consume and 10% of it from a fiber supplement.

Eating 25-30 grams of dietary fiber per day is important for achieving good health.

Use these tips to increase your fiber intake, along with the fiber chart below for fruits and vegetables.

  • Increase your fiber gradually to avoid any painful bloating and gas.
  • It’s best to have 90% of your daily fiber should come from the foods that you eat and the other 10% can come from a fiber supplement.
  • Increase your water intake by drinking half of your body weight each day in ounces.
  • A high fiber diet will help you maintain the benefits of cleansing by producing a better bowel movement.

Fiber Benefits Final Thoughts

Fiber is important for a healthy lifestyle. When looking to increase your fiber intake, avoid a dramatic increase at one time. Fiber absorbs water and increases in size when it reaches the colon. A dramatic, sudden increase of fiber can lead to painful bloating.

If you want to increase your fiber intake, be careful and start slowly. You may notice uncomfortable changes in your body if you go from zero to 100% overnight.

Fiber supplements and foods should be used together to achieve your daily fiber requirements. Fiber supplements are easy and helpful, but they don’t contain the essential vitamins and nutrients your body needs.

Use our fiber chart for guidance how much fiber is in different types of food.

Food and Fiber Chart – Your Secret Key To Better Health 

See how much fiber different foods give you, along with whether the foods are classified as a protein or starch. 

Download the Fiber Table PDF

FruitsProteinStarchPortionFiber (gms)Soluble (gms)Insoluble (gms)
Apple,w/skin1 small2.811.8
Apple sauce1/2 cup2.71.3
Apricots, canned4 halves1.2.5.7
Apricots, dried7 halves21.1.9
Apricot, fresh43.51.81.7
Avocado, fresh1/
Banana1/2 small1.1.3.8
Blackberries, fresh3/4 cup624
Blueberries, fresh3/4 cup1.4.31.1
Cherries, black12 large1.3.6.7
Cherries, canned1/2 can1.8.9.9
Currant, dried2 tbsp0.4.2.2
Dates, dried2.5 med.
Figs, dried1.5 figs2.31.11.2
Fruit Cocktail1/2 cup2.71.3
Grapefruit1/2 med.
Grapes, red15 small0.4.2.2
Grapes, white15 small0.6.3.3
Kiwi, w/skin1 large1.7.3
Mango, flesh only1/2 small2.91.71.2
Cantaloupe1 cup1.1.3.8
Honeydew1 cup0.9.3.6
Watermelon1 cup0.6.4.2
Nectarine1 small1.8.81
Orange1 small2.91.81.1
Peaches, canned1/2 cup2.71.3
Peaches, fresh1 medium211
Pear, canned1/2 cup3.7.73
Pear, fresh1 small2.91.11.8
Pineapple, canned1/3 cup1.4.21.2
Pineapple, fresh3/4 cup1.4.11.3
Plum, red2 medium2.41.11.3
Prunes, dried3 medium1.71.7
Raisins2 tbsp0.4.2.2
Raspberries1 cup3.3.92.4
Strawberries1.25 cup2.81.11.7
VegetablesProteinStarchPortionFiber (gms)Soluble (gms)Insoluble (gms)
Artichoke, cookedmedium6.54.71.8
Asparagus, cooked1/2 cup2.81.71.1
Bean sprouts1 cup1.6.61
Beets, freshv1/2 cup1.8.81
Broccoli, cooked1.2 cup2.41.21.2
Brussel sprouts1/2 cup3.821.8
Cabbage, red, cooked1/2 cup2.61.11.5
Carrots, cannedv1/2 cup1.5.7.8
Carrots, freshv1 med.
Cauliflower, cooked1/2 cup1.4.6
Celery, fresh1 cup1.7.71
Corn1/2 cup1.6.21.1
Cucumber1 cup.5.2.3
Green beans, canned1/2 cup2.51.5
Green beans, cooked1/2 cup2.81.11.7
Kale1/2 cup110
Lettuce, arugula1/2 cup.16.04.12
Lettuce, chicory1 cup1.16.26.9
Lettuce, endive1/2 cup.78.16.62
Lettuce, iceberg1 cup.5.1.4
Lettuce, radicchio1 cup.36.07.29
Lettuce, romaine1 cup.9.3.6
Lettuce, watercress1 cup.17.03.14
Mushrooms1 cup.8.1.7
Peas, canned1/2 cup3.2.42.8
Peas, frozen1/2 cup4.31.33
Pepper, green1 cup1.7.71
Spinach, cooked1/2 cup1.6.51.1
Sweet potatov1/3 cup.8.3.5
Tomato, canned1/2 cup1.3.5.8
Tomato, fresh1 med.1.1.9
Tomato, sauce1/3 cup1.1.5.6
Turnip1/2 cup4.81.73.1
V-8 juice1/2 cup.7.2.5
Yellow Squash1/2 cup.7.3.4
Zucchini, cooked1/2 cup1.2.5.7
Legumes, Nuts, SeedsProteinStarchPortionFiber (gms)Soluble (gms)Insoluble (gms)
Almondsv6 whole.6.1.5
Black beans, cookedv1/2 cup6.12.43.7
Black eyed peasv1/2 cup4.7.54.2
Brazil nutsv1 tbsp.5.1.4
Butter beansv1/2 cup6.92.74.2
Chickpeas, cookedv1/2 cup4.31.33
Coconut, driedv1.5 tbsp1.5.11.4
Coconut, freshv2 tbsp1.1.11
Hazelnutsv1 tbsp.5.2.3
Kidney beans, darkv1/2 cup6.92.84.1
Kidney beans, lightv1/2 cup7.925.9
Lentilsv1/2 cup5.2.64.6
Lima bean, cookedv1/2 cup4.31.13.2
Navy bean, cookedv1/2 cup6.52.24.3
Pinto bean, cannedv1/2 cup6.11.44.7
Pinto bean, cookedv1/2 cup5.91.94
Peanuts, roastedv10 large.6.2.4
Sesame Seedsv1 tbsp.8.2.6
Sunflower Seedsv1 tbsp.5.2.3
Split peas, cookedv1/2 cup3.11.12
Walnutsv2 whole.3.1.2
Grains, Cereal & PastaProteinStarchPortionFiber (gms)Soluble (gms)Insoluble (gms)
Barleyv1/2 cup cooked4.2.93.3
Bran, dryv1/4 cup6trace6
Bread, bagelv1/2 bagel.7.3.4
Bread, wheatv1 slice1.9.31.6
Bread, branv1 slice1.5.21.3
Bread, cornbreadv1 2 in. cube1.4.31.1
Bread, muffinv1/2 muffin.8.2.6
Bread, Frenchv1 slice.9.3.6
Bread, bunv1/2 bun.7.2.5
Bread, mixed-grainv1 slice1.9.31.6
Bread, oatmealv1/2 slice1.2.3.9
Bread, pitav1/
Bread, pumperv1 slice2.71.21.5
Bread, raisinv1 slice1.2.3.9
Bread, ryev1 slice1.8.81
Bread, sourdoughv1 slice.8.3.5
Bread, tortillav1 shell.7.3.4
Bread, wafflev1 waffle.7.3.4
Bread, whitev1 slice.6.3.3
Bulgur, cookedv1/2 cup2.9.52.4
Cereal, All Branv1/3 cup8.61.47.2
Cereal, bran flakesv1/2 cup2.1.8.3
Cereal, Cheeriosv1.25 cup2.51.21.3
Cereal, Corn Flakesv1 cup.5.1.4
Cereal, Fiber Onev1/2 cup11.9.811.1
Cereal, Nutri-grainv2/3 cup2.7.72
Cereal, Oat Branv3/4 cup42.21.8
Cereal, Puffed Ricev1 cup1.5.5
Cereal, Quaker Oatv1/2 cup2.2.81.4
Cereal, Raisin Branv3/4 cup5.3.94.4
Cereal, Rice Krispyv1 cup.3.1.2
Cereal, Shredded Wheatv2/3 cup3.5.53
Cereal, Special Kv1 cup.9.2.7
Cereal, Totalv1 cup2.6.62
Cereal, Wheat. Flakev3/4 cup2.3.41.9
Cereal, Wheatiesv2/3 cup2.3.41.6
Crackers, Matzov1 cracker1.5.5
Crackers, Melbav5 slices1.8.41.4
Crackers, Saltinev6 cracker.5.3.2
Crackers, Saltine Wheatv5 cracker.3.2.4
Flour, oatv2.5 tbsp1.81.8
Flour, ryev2.5 tbsp2.6.81.8
Flour, whitev2.5 tbsp.6.3.3
Flour, whole wheatv2.5 tbsp2.1.31.8
Milletv1/2 cup, cooked3.3.62.7
Noodles, eggv1/2 cup1.4.41
Oatmeal, cream wheatv2.5 tbsp1.1.4.7
Oatmeal, plainv1/3 cup2.71.41.3
Popcorn, poppedv3 cups2.11.9
Pretzelsv3/4 ounce.8.2.6
Rice, whitev1/3 cup.5trace.5
Rice, wildv1/3 cup.4.1.3
Spaghetti, whitev1/2 cup.9.4.5
Spaghetti, wheatv1/2 cup2.7.62.1
Wheat branv1/2 cup12.3111.3
Wheat germv3 tbsp3.9.73.2

Written and Medically Reviewed By

  • Chelsea Cleary, RDN

    Chelsea is a Registered Dietitian Nutritionist (RDN) specializing in holistic treatment for chronic digestive disorders such as Irritable Bowel Syndrome (IBS), SIBO, and Crohn’s disease. She educates patients on how they can heal themselves from their conditions by modifying lifestyle and dietary habits.

  • Julie Guider, M.D.

    Dr. Julie Guider earned her medical degree from Louisiana State University School of Medicine. She completed residency in internal medicine at the University of Virginia. She completed her general gastroenterology and advanced endoscopy fellowships at University of Texas-Houston. She is a member of several national GI societies including the AGA, ACG, and ASGE as well as state and local medical societies.