Illustration of a checked book and insoluble fiber foods

10 min read

6 Easy Ways to Add Insoluble Fiber Foods to Your Diet

Posted Sep 20, 2021 Updated Feb 24, 2024

If you’ve landed on this page, you probably already know that fiber is more than just a wellness buzzword. Instead, it’s the stuff our bodies can’t digest—the “bulk” or “roughage” that passes through our stomachs and colons pretty much intact, which makes it an essential ingredient for good gut healthIt’s kind of like a sponge that keeps things moving through your system.

But...let’s pause, do you know where fiber comes from, exactly? And what’s all this about soluble fiber versus insoluble fiber? And what are some good sources of insoluble fiber? If you're asking yourself any of these questions... you’ve come to the right place.

What Is Fiber?

First things first: Fiber is an indigestible carbohydrate found in various foods. Unlike fat, protein, or even other kinds of carbs, which your body breaks down and absorbs, your body can't digest or absorb fiber. It can come in a whole range of fruits and vegetables, but we’ll get into more of that later.

Soluble Fiber vs Insoluble Fiber

As you may have noticed on nutrition labels, there are two kinds of fiber: soluble fiber and insoluble. The former holds onto water, turning into a gel-like material in the body. The latter doesn’t dissolve in water at all, and instead adds bulk to your stool, helping food pass through your system.

How to Find Fiber on the Nutrition Label 

To find the amount of fiber contained in a product, the food label will provide this exact information. Under the “carbohydrate” category, you will see the amount of fiber listed. If you do not see fiber listed in this space, you can assume that the product you are choosing is fiber-free.

Why Do I Need Fiber?

Fiber can help support healthy bowel movements, lower cholesterol, and control blood sugar for people with diabetes. Because it’s a bulking agent, fiber also makes you feel fuller, which can help you maintain a healthy weight.1

And there’s more! (We told you it’s more than just a wellness buzzword.) Fiber can also contribute to gut health by serving as fuel for your microbes, says Stanford University Associate Professor of microbiology and immunology Justin Sonnenburg. In a 2016 study, he indicated that consuming less fiber translates to fewer microbes in the gut, while eating more fiber equals more microbes. And more microbes are a great thing for gut health.2

How Much Fiber Do I Need?

How much of this stuff should you be getting in your diet each day? The American Heart Association says most healthy people need 25 to 30 grams of dietary fiber a day from food, not supplements.

Why? High-fiber foods are typically nutritionally dense, packed with vitamins and other good stuff. So incorporating high-fiber foods into your diet instead of fiber supplements will have far-reaching effects. But sadly, most Americans get only 15 grams a day.3 Not enough, folks. Not enough.

Best Sources of Insoluble Fiber

Adding insoluble fiber to your diet really isn’t that hard if you know where to look. Chances are some of your favorite foods have insoluble fiber, and you might not even know it! Well, now you do.

1. Whole-wheat flour

If you haven’t yet tried baking with whole-wheat flour or buying whole grain pasta (or making your own whole wheat pasta!), give it a whirl. The extra texture makes for a more satisfying experience, in our humble opinion, and it’s toothsome enough that it will leave you wanting more. Plus, there are 13.1 grams of fiber in 100 grams—a whole lot more than the 2.7 grams of fiber in 100 grams of white flour.4

2. Wheat bran

Speaking of baking, how do you like bran muffins? Great. Wheat bran is a mega source of insoluble fiber; in fact, it’s 90 percent insoluble fiber. There are 24.8 grams of the stuff in one cup, as opposed to the 14.5 grams of insoluble fiber in a cup of oat bran, for example. You get the picture.

3. Nuts

You might not think of nuts as a high source of insoluble fiber, but they’re quite high! For example, a cup of whole almonds contains 17.9 grams of fiber.5 There are 7.84 grams of fiber in a cup of walnuts,6 and 13 grams in a cup of pistachios.7

4. Beans

Beans, as you might already know, are fiber-full. Cooked black beans contain a whopping 15 grams of fiber per cup, while canned baked beans contain 10 grams per cup.8

5. Cauliflower

The cruciferous veggie of the moment contains almost four grams of insoluble fiber per cup.9 You can roast the florets, slice the whole head into steaks and sear in a cast-iron skillet, or enjoy them raw. Either way, you will get a boost of fiber when you enjoy this veggie. The reason this vegetable is so beloved is that it’s sturdy and a great blank slate for all manner of preparations, so get creative while you get your fiber!

6. Potatoes

We’ll forgive you if you’re surprised by this one, but potatoes are actually a great source of insoluble fiber, too. One medium Russet potato contains almost four grams of fiber.10

6 Easy Ways to Add Insoluble Fiber Foods to Your Diet

If you need a little inspiration for working some of these foods into your everyday diet, we’ve got you covered.

1. Bake With Whole Wheat Flour

All you whole wheat flour skeptics can start by swapping in one-third a cup of whole wheat flour into your recipes and tasting the impact for yourself. Your taste buds will thank you, to say nothing of your gut. Quick breadthink zucchini bread or banana breadis a good place to start with desserts, and if you’re a bread baker, just go for it. You’ll never look back.

2. Snack Right

Put down the chips and start snacking like a grownup. That means peanut butter on that crusty whole wheat bread you just baked, crudités and dip with high-fiber veggies, popcorn, and nuts. It might be hard at the beginning. But once you find flavors and combinations you like, you’ll be delighted at how snacking can involve way more than mindlessly shoving chips in your face.

3. Start With Breakfast

Don’t skip breakfast! It’s such a good opportunity to get in that high-fiber fruit, oatmeal, bran muffins, bran cereal, whole grain bread, whole grain waffles… we could go on. Plus, starting your day with a high-fiber breakfast will leave you full and satisfied for at least a few hours. With fiber as your breakfast companion, you should be good until lunchtime.

4. Switch to Whole Grains

A lot of pre-packaged foods contain whole grains, making it easy to add fiber to your diet. At home, use whole grains in your cooking. Choose whole grains instead of refined choicesthink brown rice instead of white or whole grain bread instead of classic white.

5. Sneak in Legumes

While you’re at it, sneak in the legumes whenever you can. Making a quesadilla? Crack open a can of black or pinto beans, rinse, warm in the microwave with some olive oil, then sprinkle with salt and your spice of choice (try cumin or smoked paprika for starters). Toss them into your quesadilla and you’ve added flavor, texture, and, you got it, fiber, with about two minutes of extra work. Throw some chickpeas into your salad, or white beans on top of your soup. It’s really that easy.

6. Drink Your Fiber

Drink your what?! We know that doesn't sound appetizing, but trust us, it can be. One can of OLIPOP has 9 grams of dietary fiber. That's 32% of your daily value of fiber in one can of delicious soda! 

Adding Insoluble Fiber to Your Diet: The Takeaway

Adding insoluble fiber to your diet isn’t a difficult endeavor, and the effects will pay off immediately. Making simple swaps in your diet can help you meet your daily quota, and in turn, support your gut health in a natural way. We’ll drink—some OLIPOP—to that!

Ready to learn more about fiber? Head to our blog for even more fiber-filled topics like how much fiber to eat every day, the fiber gap, tips from a registered dietitian, and more.


  1. “How to Add More Fiber to Your Diet.” Mayo Clinic. , 2021.
  2. Edward C Deehan and Jens Walter, “The Fiber Gap and the Disappearing Gut Microbiome: Implications for Human Nutrition - PubMed,” Trends in Endocrinology and Metabolism: TEM 27, no. 5 (May 1, 2016),
  3. UCSF Health. “Increasing Fiber Intake.” UCSF Health, March 14, 2019.
  4. “FoodData Central.”, 2021.
  5. “FoodData Central.”, 2021.
  6. “FoodData Central.”, 2021.
  7. “FoodData Central.”, 2021.
  8. “Best Sources of Insoluble Fiber & Benefits of Insoluble Fiber - FAFHHC.” Family Always First Home Care, May 6, 2020.
  9. “Best Sources of Insoluble Fiber & Benefits of Insoluble Fiber - FAFHHC.” Family Always First Home Care, May 6, 2020.‌
  10. “FoodData Central.”, 2021.
Cheat Sheet
  • Fiber doesn’t just help promote healthy bowel movements. It’s great for gut health, and helps keep cholesterol and weight in check.
  • Soluble fiber and insoluble fiber are both important. One dissolves in water into a gel-like substance in the body, acting like a sponge, and the other acts as a bulking agent.
  • With the long list of fiber-rich foods, getting enough fiber in your diet is easier than you think.
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