Top 25 Insoluble Fiber Foods and Comparison to Soluble Fiber

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By Jillian Levy, CHHC

April 23, 2019

Fiber is defined as “dietary material containing substances such as cellulose, lignin and pectin that are resistant to the action of digestive enzymes.” In other words, fiber is the substance found in plant foods (carbohydrates) that is not metabolized in the stomach and intestines, but rather passes through the gastrointestinal tract and makes up a part of stools.

The Dietary Guidelines for Americans states that adults should aim to get about 14 grams of total fiber each day for every 1,000 calories they eat. Unfortunately, it’s estimated that the average American consumes only about half of the recommended amount of dietary fiber on most days — due to eating lots of processed foods and refined grains, and not eating enough vegetables, fruits, legumes, and so on.

Why is it so important to to eat high-fiber foods? Insoluble fiber and soluble fiber each have unique benefits. Insoluble fiber is the type that helps to prevent constipation, cleans out the GI tract and even helps protect against serious problems like colorectal cancer.

What Is Insoluble Fiber?

There are two main types of dietary fiber:

• Insoluble fiber, which does not dissolve in water and is left intact and undigested. Insoluble fiber can help to speed up the passage of food through the stomach and intestine. It also adds bulk to the stool and can help relieve constipation.
• Soluble fiber, which dissolves in water, retains water, and forms a gel-like substance in the colon. It slows down digestion and nutrient absorption from the stomach and intestine.

Which foods are high in insoluble fiber? Some examples include: wheat bran, many types of vegetables, nuts and seeds, potatoes, fruit with skin, legumes and whole grains. There are actually several different types of insoluble fibers found in various foods, some of which include cellulose and lignin fibers.

Health Benefits

1. Helps Prevent and Treat Constipation

One of insoluble fiber’s main jobs is to provide bulk in the intestines and to form stool, which leads to regular bowel movements and constipation relief. Insoluble fiber does not dissolve in water like soluble fiber does, so it helps move material through the colon by increasing the bulk of stools.

2. Slows Down Absorption of Carbohydrates/Sugar

While fiber is found in carbohydrate foods, it doesn’t raise blood sugar levels; in fact it helps to slow down absorption of sugar from carbs, which is beneficial for stabilizing blood sugar.

A diet high in both types of fiber has other metabolic and health benefits too, such as protecting against obesity, cardiovascular disease, diabetes and metabolic syndrome.

3. Can Help With Appetite Control and Weight Management

Insoluble fiber found in high-fiber foods can help to make you feel full and keep you satisfied between meals. Insoluble fiber is also not technically a source of calories since it’s undigested and remains intact once eaten.

4. May Help Prevent GI Issues Like Diverticulosis and Hemorrhoids

Insoluble fiber helps to speed up the movement and processing of waste in the digestive system, which is why it’s useful for producing regular bowel movements. It may also help to prevent gastrointestinal blockages and straining that accompanies constipation, which can lead to problems like hemorrhoids.

Additionally, insoluble fiber helps to absorb and sweep out byproducts and carcinogens from the gut, lowering the chances of developing problems like SIBO, diverticulosis, etc.

4. May Help The Risk for Developing Colorectal Cancer

Studies have found that a higher total dietary fiber intake is associated with a significantly reduced risk of developing colorectal cancer. Two food groups that are high in insoluble fiber, whole cereal grains and whole pieces of fruit, have been shown to be especially protective against colon cancer formation.

Researchers believe that increased fiber intake may have cancer-fighting effects because it leads to a reduction in fecal carcinogens, reduced transit time and bacterial fermentation of fiber to short-chain fatty acids that have anticarcinogenic properties.

Is insoluble fiber good for IBS? This depends on the type of IBS someone has, their food personal “triggers” and a person’s specific symptoms, such as whether they tend to struggle with diarrhea or constipation more often.

Insoluble Fiber vs. Soluble Fiber

What is the difference between soluble and insoluble fiber? And do you need soluble or insoluble fiber, or both?

Many foods contain both soluble and insoluble fiber, and both types of fiber are important parts of a healthy diet, since both have been shown to help with appetite control, weight management, digestion, bowel movements, cholesterol balance, and so on.

The job of soluble fiber is to create a gel in the digestive system. It helps to bind with fatty acids, which is beneficial for maintaining healthy cholesterol levels and heart health. Soluble fiber also prolongs stomach emptying, which improves absorption of nutrients, provides satiety after eating and controls hunger. Soluble fiber can also regulate blood sugar levels, helping to prevent spikes in blood sugar and risk for problems like insulin resistance or diabetes.

Soluble fiber is found in foods like beans, legumes, oats, barley, berries and some vegetables — many of which also provide insoluble fiber.

Which is better for constipation, soluble or insoluble fiber?

Insoluble fiber is usually better for preventing constipation, although both types of fiber can be helpful for staying regular and free from digestive issues.

Insoluble fiber won’t ferment in the gut, but soluble fiber does ferment in the stomach, which can lead to some bloating and gas. Soluble fiber is digested by bacteria in the large intestine, which wind up releasing gas, sometimes which causes lots of flatulence when following a high-fiber diet. On the other hand, insoluble fiber remains intact while traveling through the GI tract, which helps with constipation and also tends to produces less gas.

This is why a very high-fiber diet may sometimes make IBS symptoms worse, although it depends on the person. Because each person reacts to various fiber-containing foods differently, it’s important to increase these foods in the diet gradually and also to drink plenty of water.

Maybe you’re wondering which type of fiber some of your favorite foods provide? Let’s take a look at a few examples:

• Soluble fiber is found in foods such as oat bran, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables.
• Are bananas soluble or insoluble fiber? A bananas has about 2–3 grams of fiber, most of which is insoluble fiber, although it contains both types.
• Is rice soluble or insoluble fiber? A cup of brown rice has about 3–4 grams of fiber, almost all of which is insoluble.
• Is spinach and lettuce soluble or insoluble fiber? Dark leafy greens are a great source of insoluble fiber. One cup of cooked spinach has about 6 grams of fiber, about 5 of which is insoluble fiber.

Top 25 Insoluble Fiber Foods

Below are some of the top insoluble fiber foods:

1. Wheat bran and wheat germ
2. Oat bran
3. Beans, lentils and legumes of all kinds (kidney, black, garbanzo, edamame, split peas, lima, navy, white, etc.)
4. Berries, including blackberries, blueberries, raspberries, strawberries, etc.
5. Whole grains, especially barley, quinoa, sorghum, millet, amaranth, oatmeal and rye
6. Turnips
7. Green peas
8. Okra
9. Spinach
10. Radishes
11. Rutabaga
12. Coconut (grated flakes or flour)
13. Cocoa
14. Apples with skin
15. Pears with skin
16. Flaxseeds
17. Avocado (Florida avocados have more than California avocados)
18. Sunflower seeds
19. Potatoes and sweet potatoes
20. Dried apricots, prunes, raisins, dates and figs
21. Almonds
22. Walnuts
23. 100% whole grain pasta and breads
24. Passionfruit
25. Popcorn

Supplement Options and Dosage

How much insoluble fiber should you get each day? There isn’t currently a recommended daily intake of strictly insoluble fiber, but rather total fiber. The recommended intake for total fiber (soluble and insoluble combined) for adults 50 years and younger is 38 grams per day for men and 25 grams per day for women.

Adults over 50 may struggle with indigestion if they consume too much fiber, so around 30 grams for men and 20 to 25 grams for women per day is recommended, although eating more is not a bad thing if it doesn’t cause any issues.

Food labels usually show the total grams of fiber per serving, not just grams of insoluble fiber. This can make it difficult to know exactly how much of each type of fiber you’re consuming — however, the real goal should be to eat a variety of high-fiber foods, rather than focusing too much on the numbers.

While it’s ideal to get fiber from whole foods, fiber supplements are an option for people who can benefit from getting even more insoluble fiber, such as to help prevent constipation. In supplement form, fiber is extracted from natural sources, such as psyllium husk, in order to form a concentrated dose. Each fiber product has a different strength, so always follow directions carefully, starting with a lower dose and increasing if needed, while also drinking plenty of water. 

If you’re experiencing diarrhea, keep in mind that you are better off with a soluble fiber supplement than one that contains insoluble fiber.

Risks and Side Effects

Is insoluble fiber ever bad for you? If you’re prone to diarrhea or loose stools, perhaps because you suffer from inflammatory bowel disease or IBS, then eating lots of insoluble fiber may potentially cause you discomfort and worsen symptoms. Use caution when increasing insoluble fiber intake if you have celiac disease or are gluten intolerant.

If you change your diet to include more foods high in insoluble fiber, and then notice loose stools or other GI issues, it’s a good idea to cut back on the amount of fiber you’re consuming and also mention this to your doctor in order to get their advice. You may also want to follow an elimination diet to pinpoint which types of high-fiber or FODMAP foods are problematic for you.

You also want to be sure to drink plenty of water when eating a high-fiber diet, since water helps fiber do its job properly.

Your Go-To Insoluble Fiber Foods List for Better Digestion

Feel like your digestion is off? The right foods can help. Try working itms from this insoluble fiber foods list into your everyday meals!

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What Is Insoluble Fiber?

When it comes to fiber, there are two different types: soluble and insoluble. The soluble fiber found in oat bran, barley and some fruits and vegetables tends to absorb water and slow down digestion. The insoluble fiber in whole grains, nuts, seeds, fruits with skin and certain vegetables, on the other hand, can bulk up the stool and help it pass through your intestines faster.

But what grains, fruits and vegetables are high in insoluble fiber? The following insoluble fiber foods list will give you a starting point for what to eat.

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Amaranth

Amaranth is a great way to get your fiber. It may not be a familiar choice, but it’s a seed worth getting to know. Why? A single cup of amaranth offers a whopping 20 grams of insoluble fiber! You can learn how to cook this fiber-rich grain here.

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Taste of Home

Cauliflower

Cooked cauliflower is more than a great side dish; it’s also rich in insoluble fiber. Just one cup contains almost four grams! Note that while raw cauliflower also contains insoluble fiber, the amount almost doubles when you cook it. Find clever ways to cook cauliflower.

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Green Peas

Whether you work them into soups, pasta salads, smoothies or simple side dishes, peas pack a lot of fiber into your meal. Eating one cup of peas will deliver more than 15 grams of insoluble fiber.  You can even start cooking with a bag of frozen peas.

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Cooked Prunes

Eating cooked prunes to keep things moving is well-known enough to be a cliche. You’ll understand why when you see the fruit’s insoluble fiber content: over 12 grams in one cup of cooked, unsweetened prunes. Find more famous high-fiber foods.

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Dark, Leafy Greens

You already know dark greens are good for you, but did you know they can aid digestion as well? Cooked spinach contains between four and five grams of insoluble fiber per cup, and cooked chard has at least three grams.

Learn to love leafy greens with hearty recipes starring spinach, kale, Swiss chard, collards and more.

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Blackberries

When it comes to fruits with insoluble fiber, your best bet is to stick to fruits that you eat with the skin on. Fruits that need to be peeled, such as a banana, for example, may contain insoluble fiber, but not as much. A banana has insoluble fiber, but only about two to three grams of both kinds total. A better choice would be blackberries, which have more than six grams per cup!

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Nuts

Many nuts make good sources of insoluble fiber. Almonds, for example, have more than 14 grams per cup, and pine nuts, 13 grams per cup. Reach for pistachios or peanuts, too. Both have over 10 grams of insoluble fiber per cup. Find healthy ways to add nuts to your diet.

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Beans

Beans are another great way to up your fiber intake—especially with certain types. To get the biggest insoluble fiber bang for your buck, opt for roasted soybeans (almost 17 grams per cup) or cooked pinto beans (almost 11 grams per cup).

Looking for new bean recipes? Here are 100 great ideas.

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Unpeeled Apples

An apple a day may not keep the doctor away, but it will help you boost insoluble fiber in your diet! Eaten with the skin on, a single apple contains almost three grams. If you’re tired of the same old Red Delicious, check out this roundup of 15 unusual types of apples at the grocery store.

Originally Published: July 08, 2019

Shanna Mallon

Shanna Mallon is an experienced copywriter and food blogger with a master’s degree in Writing. She likes tested recipes, organized refrigerators and the pleasure of a good bite.

90,000 Most of us consume very (!) little fiber. Why is this dangerous and how to fix the situation?

Nutrition

A minimum of 30 grams of fiber should be ingested daily. But, most likely, you eat 2 times less. We tell you why we need dietary fiber, what foods are especially rich in it, and whether it is worth taking fiber in supplements.

Residents of Russia on average consume no more than 12-15 grams of fiber per day – such figures are called by the Center for Hygienic Education of the Population of Rospotrebnadzor. This is almost two times lower than the norm – at least 30 grams of fiber should be supplied to the body daily.

How can I fix this?

It’s simple – eat more plant-based foods, including vegetables, beans, fruits, whole grains, and nuts. By the way, in April 2019, the medical journal The Lancet published the largest study on the relationship between nutrition, health and mortality. So dislike for these categories of products is one of the main causes of premature death.

• Excellent sources of fiber: beans (all kinds!), peas, chickpeas, artichokes, whole wheat flour, barley, bulgur, bran, raspberries, blackberries and prunes.
• Good sources of fiber: lettuce, dark leafy greens, broccoli, cauliflower, sweet potato, carrots, pumpkin, potatoes with skins, corn, beans, asparagus, kale, whole grain pasta, oats, nuts, raisins, pears, strawberries, oranges, bananas , blueberries, mango and apples.

A sure way to increase the amount of fiber in your diet is to replace refined white flour products (be it bread or pasta) with whole grain products. And in general, give preference to whole, rather than processed foods – you can read how they differ, you can read here.

Soluble and insoluble fiber: what is the difference for the body?

Fiber is divided into two types: one is soluble in water, the other is not. Soluble fiber has been linked to lowering that “bad” cholesterol, regulating blood sugar, and reducing the risk of heart disease and type 2 diabetes. It is found in beans, peas, lentils, oatmeal, oat bran, nuts, seeds, psyllium, apples, pears, strawberries and blueberries.

Insoluble fiber helps maintain stool regularity (dietary fiber increases the volume of feces and reduces the time it takes for the food bolus to pass through the intestines!) and prevents constipation. It also reduces the risk of developing certain types of cancer, such as rectal cancer. High-fiber foods help you feel full longer and, as a result, prevent overeating. Sources of insoluble fiber include whole grains, barley, whole grain couscous, brown rice, bulgur, wheat bran, nuts and seeds, carrots, cucumbers, tomatoes and zucchini, celery and green beans, dark leafy vegetables, and grapes.

Simple Fiber Meal Plan

Here is a sample daily menu that contains almost 34 grams of fiber:

• Breakfast: whole grain bran flakes (5 g fiber), half a banana (1.5 g fiber) and skim milk.
• Snack: 24 almonds (3.3 grams fiber) and 1/4 cup raisins (1.5 grams fiber).
• Lunch: Turkey sandwich made with 2 slices of whole grain bread, lettuce and tomatoes (5 grams fiber) and an orange (3.1 grams fiber).
• Snack: yogurt with half a glass of blueberries (2 grams of fibre).
• Dinner: Grilled fish with romaine lettuce and shredded carrots (2.6 grams fiber), 1/2 cup spinach (2.1 grams fiber), and 1/2 cup lentils (7.5 grams fiber).

7 Ways to Add More Fiber to Your Diet

1. Start your day with a whole grain cereal that contains at least 5 grams of fiber. Look at the ingredient list to make sure a whole grain (such as whole wheat, whole rye, or whole oats) tops the list.
2. Read labels and look for foods that contain at least a few grams of fiber per serving. A good source of fiber is 2.5-4.9 grams of fiber per serving. An excellent source contains 5 grams or more per serving.
3. For sandwiches, use whole grain bread with at least 2-3 grams of fiber per slice.
4. Choose whole fruits over juice. Whole fruit can have twice as much fiber as a glass of juice.
5. Add beans to soups, stews, egg dishes, salads. Replace all meat with beans at least once a week.
6. Experiment with international cuisines (eg Indian or Middle Eastern) that use whole grains and beans as main courses.
7. Snack on raw vegetables with bean sauce or hummus.

If you find that your diet is extremely low in fiber, it is best to increase your fiber intake gradually and also drink enough water so that your digestive system has time to adjust to the change. For example, you can add about 5 grams of fiber every day until you reach your goal.

What about fiber supplements?

It is unclear whether fiber found in supplements or fortified foods provides the same health benefits as its natural sources. Because of this, most fiber supplements are aimed at preventing constipation rather than, say, lowering cholesterol.

If you still want to get fiber from supplements, talk to your doctor to find out which one is right for you. Fiber supplements come in a variety of forms, from capsules to powders to chewable tablets, and contain what’s called “functional fiber” that can be extracted from natural sources or produced in a lab.

Natural additives include lignin (a compound found in plant cells), cellulose (sugar from plant cells), pectin (sugar from fruits and berries), gum (sugar found in seeds), and psyllium (psyllium husk). Industrial dietary fibers are polydextrose, polyols and maltodextrin.

If you add too much fiber to your diet (especially from supplements), it can cause unpleasant side effects such as bloating and stomach cramps. In addition, studies show that adding 50 grams or more of fiber per day can negatively affect your body’s absorption of nutrients. Also, talk to your doctor about possible interactions between fiber supplements and any medications you are taking. The fact is that it can reduce the rate of absorption of certain drugs.

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Author:

Katerina Reznikova,
October 29, 2022

Insoluble fiber foods: advantages and disadvantages

Fiber is the main nutrient in the diet for proper intestinal transit. Insoluble fiber does not dissolve in water, does not form gels (non-sticky), and is more difficult to digest. Thus, this type of fiber, including cellulose, contributes to the formation of structures such as the outer layers of whole grains (bran), celery strands, seed hulls, and corn kernel skins.

Even after several hours of cooking, insoluble fiber retains its shape and coarse texture, effectively aiding the digestive system, increasing stool volume and making it easier to pass. The main components of insoluble fiber and resistant starch are cellulose, hemicellulose and lignin.

Index

• 1 Tipos de Alimontos
  • 1.1 Vegets
  • 1.2 Fruits
  • 1.3 whole grain
  • 1.4 Nuts and seeds
• 2 Benefits
• 3 Contraindications
• 4 Insoluble fiber supplements

Tipos de Alimentos

Insoluble fiber can be obtained from various sources such as fruits, nuts , seeds, vegetables, wheat bran or whole foods. Below we show the foods rich in insoluble fiber, depending on the type of food.

Vegetables

• cooked artichoke
• Cooked Brussels sprouts
• Raw carrots
• cooked cabbage
• baked beans
• potatoes with skins
• Soy (edamame)
• peeled sweet potatoes

Fruit

• red apple with skin
• Apricots with peel
• Blueberry
• Dried figs
• kiwi
• Mango
• Feather
• raspberry
• Strawberry

Whole grains

• boiled barley
• Brown rice
• Oat bran
• dry oats
• boiled oats
• Quinoa (seeds) dry
• Quinoa cocida
• Wheat bran
• Wheat paste

Nuts and seeds

• almonds
• Black beans
• Flax seeds
• nut
• beans
• lentils
• psyllium husk
• Sesame seeds
• green peas
• Sunflower seeds
• Nuts

Benefits

While soluble fiber dissolves in water, insoluble fiber is not broken down or completely broken down by intestinal bacteria. Instead, it retains water, promoting larger and more regular bowel movements. This, in turn, can be helpful in preventing intestinal disorders such as diverticulosis and hemorrhoids as it can keep the good bacteria in the gut.

Insoluble fiber has many benefits for gut health, including reducing the risk of constipation and preventing infections in the gut. It also removes cancer-causing toxins and carcinogens and helps prevent colon cancer by maintaining a healthy pH in the gut.

Many claim that it helps to lose weight and to some extent prevents heart disease and inflammation. Insoluble fiber is sometimes referred to as a filler because it aids digestion and has health benefits, such as lowering serum cholesterol levels.

This type of fiber contains no calories and generally has little nutritional value because it cannot be digested immediately. Adds bulk as semi-digested food passes through the body as an indigestible substance. As a result, insoluble fiber is extremely beneficial for the human body. Consuming insoluble fiber in reasonable amounts poses very little risk as a main component of the diet.

Contraindications

If you are prone to loose stools or diarrhea, it is not recommended to increase your intake of insoluble fiber. This may exacerbate the problem. We’d rather choose foods that are mostly soluble fiber, such as oats and bananas.

People with irritable bowel syndrome should be careful about the types of fiber they consume. Irritable bowel syndrome, a common gastrointestinal disorder, affects 10 to 20 percent of adults worldwide.

We won’t completely avoid fiber as it offers valuable benefits such as lowering blood cholesterol levels, improving glycemic control and helping with body weight management. However, be aware that insoluble fiber can contribute to symptoms such as bloating, bloating, and flatulence.

Insoluble Fiber Supplements

Currently, there is no recommended daily allowance for not only strictly insoluble fiber, but also total fiber. The recommended intake of total fiber (soluble and insoluble together) for adults aged 50 years and younger is 38 grams per day for men and 25 grams per day for women. .

Adults over 50 may experience stomach upset if they eat too much fiber, so about 30 grams for men and 20 to 25 grams for women per day is recommended, although eating more is not harmful if it does not cause any problems.

Food labels usually list total fiber in grams per serving, not just grams of insoluble fiber. This can make it difficult to know exactly how much of each type of fiber you are getting; however, the real goal should be to eat a variety of high-fiber foods and not get too hung up on the numbers.

While getting fiber from whole foods is ideal, fiber supplements are an option for people who may benefit from getting even more insoluble fiber, for example to prevent constipation. In supplement form, fiber is extracted from natural sources such as psyllium husk to form a concentrated dose.