Different Types of Dietary Fiber and Why We Need it–Best Sources

FIBER!?! Found in whole foods like vegetables, fruits, nuts, seeds yet  the average American is actually low on their daily intake. Why? Because the bulk of processed foods that we consume actually removes most of the fiber. We all know that we need said fiber, but do we know WHY? Because you know I love asking WHY and finding the answers (much like you should). So, we know that we need fiber in our diet (at least 25-40g a day) but do we know what it actually does in the body, what the different types are, and what foods it is found in? Well, today we are going to chat about all of this! So look no further than RIGHT HERE to learn all about different types of dietary fiber and why we need it!

What is fiber

First of all, fiber and dietary fiber are the same thing (in the nutritional world). We all know there are cloth fibers, but in this case, they are interchangeable words. Dietary fiber is a plant based nutrient that is essential for our health! It is technically a carbohydrate, but it differs in a sense that fiber CANNOT actually be fully broken down into sugar molecules to be used as energy. But it does play a HUGE role in our health. So, what is the role of fiber in the body? The benefits of fiber include helping digestion and aiding in many other things like blood sugar control, heart health, weight management (metabolism health) and even skin health! Not to mention it can help protect us from stroke, IBS, gallstones, and hemorrhoids! Have you ever noticed after a bout of not-so-great foods or alcohol that you are feeling “puffy”? This is because you are likely holding onto extra water. This happens when we have an imbalance of water, salt and FIBER! Usually the foods we eat are high in salt, which is going to increase our water retention. Fiber has HUGE benefits at this time because it is going to either mix with the water and ferment or it is going to be carried out of the body as waste! So now, lets talk about the different types of fiber.

Types of Dietary Fiber

There are two different types of fiber: soluble and insoluble. Put simply, soluble fiber dissolves in water and slows down digestion (prolongs feeling of fullness), while insoluble fiber does not dissolve in water and it speeds up digestion (regular bowel movements). You can also go a bit deeper into things like functional fiber (added to foods), fermentable fiber, viscous fiber and resistance starch..but we are going to keep things simple with the top tier – soluble and insoluble.

Soluble Fiber:

As I said, soluble fiber mixes with water, ferments and forms a gel-like substance. This substance sits in the gut and makes us feel full. Because this type of fiber fully broken down when mixed with water, it helps us digest nutrients and acts as a prebiotic (feeds good bacteria for better gut health). For those that suffer with any kind of gut issues, whether it be IBS, leaky gut, IBD, Crohns, diverticulitis, a diet high in soluble fiber is exactly what you want. On the other hand, soluble fiber is what gives off acid and gases in the digestive system and can cause bloating. Soluble fiber is also great for lowering blood sugar levels (because it hangs out in the stomach), reduce LDL cholesterol, and aid in weight loss (keeping you fuller longer and steadying blood sugar levels). The different types of soluble fiber include gums, pectins, psyllium, beta-glucans, and inulin.

Insoluble Fiber:

Insoluble fiber is the fiber that does not mix with water and is not absorbed by the body. This means, it basically makes its way through the body without any breakdown (ever looked at your stool and were able to recall exactly what you ate)? The benefit of this fiber is to keep things moving on through the body. It does not hangout in the gut, in gets in and it gets out and there are no worries! This also means that insoluble fiber increases detoxification of the body and helps us get rid of “crap” that is hanging out in the body. Insoluble fiber is also responsible for creating the BULK of our foods (like riced cauliflower and zucchini). Those with digestive issues do need to be careful of insoluble fibers though as it is much like rubbing sand in an open wound. Benefits of insoluble fiber include decreasing risk of constipation, and hemorrhoids. The different types of insoluble fibers include lignin and cellulose.

Resistance starch:

Although not technically one of the “types” of fiber we frequently talk about, resistance starch is also very good for us! This starch is found in carbohydrates and acts like insoluble fiber, in that it makes its way through our digestive tract basically untouched. It has been known to improves digestive health, enhances insulin sensitivity, lowers blood sugar levels and significantly reduces appetite. Although it is found in fewer foods (and supplements) you can actually create resistance starches.

High Fiber Foods

You may be thinking of bran (bran muffins, raisin bran) or cereals when it comes to fiber, but the truth is; those are not the best types of fiber. Especially this day in age when the production industry is just trying to make as much food as possible, this fiber is actually ADDED to the food after it is processed, also known as functional fiber. This is the type of fiber your body doesn’t really know what to do with. Your best bet is to eat whole foods that are rich in fiber, and these include:

Soluble Fiber:

• Carrots

• Winter squash (butternut, kabocha, acorn, pumpkin, delicata, spaghetti)

• Summer squash (yellow, zucchini, tatuma, pattypan)

• Starches (yams, sweet potatoes, potatoes)

• Turnips

• Rutagaga

• Parsnips

• Beets


• Oats

• Lentils

• Citrus fruits

• Berries (aka things with seeds)

• Kiwi

• Chia seeds

• Flaxseeds

Insoluble Fiber:

• Greens (spinach, lettuce, kale, collards, arugula, etc)

• Peas (whole peas, snap peas, snow peas)

• Green Beans

• Kernel Corn

• Bell peppers

• Eggplant

• Celery

• Cucumbers

• Tomatoes

• Pumpkin seeds

• Sesame Seeds

• Nuts

• Onions (shallots, green, scallions, leeks)

• Garlic

• Cruciferous vegetables (cabbage, broccoli, bok choy, brussel sprouts, cauliflower)

Resistance starch:

• Seeds

• Unprocessed whole grains

• Peans

• Beans

• Raw potatoes

• under-ripe bananas

• Cashews

• Legumes

• Raw oats

• Cooked AND COOLED sweet potatoes and white rice

Fiber Digesting tips

If you have read other blogs (aka this one on digestion) you know that I struggle with gut issues. Whether it be because of IBS, hormonal birth control or just food intolerances, I have been on a long journey to figuring out foods that work and foods that don’t. I found a few tips from Chris Kresser that I think are great to know if you too struggle with digestion!

• Never eat insoluble fiber foods on an empty stomach. Always eat them with other foods that contain soluble fiber.

• Remove the stems and peels from fruits and veggies high in insoluble fiber (removing peels on squash can also help).

• Dice, mash, chop, grate, or blend high-insoluble fiber foods to make them easier for the body to break down

• Insoluble fiber foods are best eaten well-cooked: steamed thoroughly, boiled in soup, braised.

•  Avoid eating a lot of different vegetables in stir-fries.

• If you do eat raw veggies, make sure they are prepared as stated above!

So, moral of the story…eat real food (as I always preach, and if you need food switching ideas, check out my blog here on healthy alternatives to our favorite foods) and you will be just fine! Unless you have digestive issues, then I would focus on the things stated above to start to eliminate your symptoms! And lastly, if you are holding water or not pooping…CHECK YOUR FIBER!

Do you like these blogs and all the information they include? Then you will LOVE my weekly newsletter! I take topics YOU suggest and break them down in simpler terms, join my tribe and start learning with us!



More posts like this!

Whole30 Diet Rules

Meditation Techniques for Anxiety

Beginner Bodyweight Workout

author: Haley Perry