In this post you will learn everything you need to know about fiber and how it can benefit your health. Some highlights include how fiber can help with weight loss, lower cholesterol, balance blood sugar, and more. As a treat for getting through the whole post, there is a printable list of high fiber foods that you can start incorporating into your diet today.
I recently read the book Fiber Fueled by Will Bulsiewicz MD, MSCI, and even though I knew fiber was an important part of optimal health, reading his book taught me just how profoundly beneficial fiber is.
In addition to reading Fiber Fueled I have also listened to Dr. Bulsiewicz on several podcasts. It was on one of those podcasts where he said that his goal is to "make fiber sexy". This idea made me laugh and I'm here to support his cause!
When most people think of fiber, they think of its role in preventing constipation. Fiber does contribute to regular bowel movements, but it does so much more and I'm here to tell you all about it.
Fiber can have huge impacts on health in regards to both treating and preventing disease. Unfortunately, fiber doesn't always get the attention that it deserves for that. In this post I’m going to change that. Here is what you will learn about:
Table Of Contents
- What exactly fiber is
- How fiber can benefit your health
- Fiber and weight loss
- Fiber and cardiovascular disease
- Fiber and blood sugar
- Fiber and IBS
- High fiber low FODMAP foods
- How much we should be eating each day
- Fiber supplements
- Whole food "fiber boosters"
- Free download - high fiber foods printable list
What is fiber?
Fiber is the edible parts of plants that are resistant to digestion and absorption in the small intestine (1). It is found in fruits, vegetables, whole grains, nuts, and seeds. Fiber can be split into two different groups - soluble and insoluble fiber. Both are important to optimal health but have different benefits and functions.
Insoluble fiber adds bulk to your stool and can help food to move more quickly through your digestive tract.
- Food sources: whole grains, bran, nuts, and seeds.
Soluble fiber attracts water and turns into a gel in your digestive tract. This can slow digestion which contributes to a lower blood sugar response and feeling full for longer after eating meals.
- Food sources: fruits, vegetables, oats, and barley.
Most plants contain a combination of both soluble and insoluble fiber.
Curious about other high fiber foods? Click here for a printable list of high fiber foods.
Health Benefits of Fiber
The benefits of fiber are pretty vast. Most notably, a higher intake of fiber has been shown to lower risk of heart disease, cancer, type 2 diabetes, and to help people lose weight (1).
Fiber also helps your body to excrete toxins, including carcinogenic substances (1).
Lastly, when you eat more fiber you are typically eating more plants, which also means you are eating more phytochemicals and antioxidants. Both of these compounds lower inflammation in the body and reduce free radicals, ultimately benefiting your health (1).
Fiber and Weight Loss
Fiber is one of the most helpful nutrients for weight loss and something that most people are not eating enough of. I frequently work with my weight loss clients on evaluating their fiber intake. Fiber can help you to feel full, which can prevent overeating and ultimately help you to achieve weight loss (1).
Fiber also feeds the "good" bacteria in your gut. When the good bacteria is fed and happy, they pay us back by producing something called short chain fatty acids. These benefit your health in many ways, one of which is assisting in weight loss (1). It does this by promoting the release of the hormone that tells your body you are full and thus helping to prevent overeating (1).
Fiber and Cardiovascular Disease
Fiber can reduce your risk of heart disease by decreasing the absorption of bad cholesterol (LDL cholesterol) in your blood. This is helpful because higher levels of LDL cholesterol are associated with an increased risk of heart disease.
Statin medications are typically the most effective treatment for lowering LDL cholesterol. However, some people do not tolerate statins and they can be quite expensive. Recently fiber has been recommended to increase the effectiveness (sometimes by double!) of statins and allow for people to lower their dose so they may tolerate the drug better (2).
Fiber and Blood Sugar
Similarly to how fiber can lower cholesterol, it can do the same for blood sugar (1). Fiber can reduce and slow the absorption of sugar in your blood. Meaning, if somebody consumes the same amount of carbohydrates but the one that is higher in fiber will have a lower blood sugar response. More fiber = better blood sugar response.
This also partially explains how fiber can help with weight loss. Stable blood sugar can make weight loss much easier.
Fiber and Irritable Bowel Syndrome
If you've gotten this far and you want to start eating more fiber but feel like foods high in fiber make you feel miserably, you may be somebody who suffers from irritable bowel syndrome (IBS). Even though fiber is good for you, not all people can tolerate all types of fiber, especially those with (IBS). The irony here is that fiber is also what can help to heal somebody's gut and improve their IBS symptoms.
So, if you have IBS don't give up on fiber completely! You'll need to go slow and choose fibers that are better tolerated than others. This will help you to slowly heal your gut and get you to a place where you can tolerate most foods again. This means there is hope for you to be able to eat a diverse range of fiber and therefore reap the benefits of a diet high in fiber but it may take a little extra attention. Working with a registered dietitian can be helpful in navigating this.
Note: IBS is characterized by stomach pain, constipation, and/or diarrhea. People with IBS can be more sensitive to fiber and sometimes need to be more careful when it comes to the types of fiber they eat.
FODMAP (fermentable fibers)
In addition to fiber, there are certain types of carbohydrates that people with IBS may have trouble digesting called FODMAPs.
FODMAP is an acronym that stands for several different groups of fermentable carbohydrates that are found in plant foods. These carbohydrates contain fermentable fibers and are more likely to cause stomach upset for those with IBS.
Temporarily following a low FODMAP diet is often used to help identify food sensitivities and alleviate symptoms in those with IBS. The diet works by eliminating all foods that are high in FODMAPs and strategically one-by-one adding back in foods from each FODMAP category. This helps people to identify the specific foods that may be causing their IBS symptoms. Theoretically, as you improve your gut health, you should be able to better tolerate high FODMAP foods.
Important notes about following a low FODMAP diet
While the low FODMAP diet can be very effective, one of the drawbacks is that it is highly restrictive, often resulting in a lower fiber intake. Even more so, an often overlooked component of the low FODMAP diet is that it is meant to be temporary. It was never designed to be followed long term given it is restrictive nature. If followed long term, a low FODMAP diet can actually have a negative impact on your gut health. This is partially because the number one predictor of good gut health is diversity in the plant foods you eat. Specifically, studies show that eating at least 30 plant foods per week can significantly improve gut health.
If you struggle with IBS and want to follow a low FODMAP diet, it’s important to work with a registered dietitian or doctor who is familiar with this type of diet.
High Fiber Low FODMAP Foods
For people with IBS that have difficulty with high FODMAP foods, meeting their fiber needs may be difficult. The below foods can help. These foods are low in FODMAPs while still being high in fiber and therefore should be well tolerated by those with IBS.
- Chia seeds
- Baked potato with skin
- Brown rice
How much fiber should you be eating?
It is recommended that women eat at least 25g of fiber per day and men consume at least 38g of fiber per day.
This may not seem like much however, only about 50% of Americans consume the recommended amount (3).
How does fiber work it's magic?
You’ll notice that there are quite a few benefits to eating fiber and you may be wondering how exactly fiber works it’s magic.
The ways fiber can improve health can be broken into 3 categories:
- Decreases inflammation
- Inflammation is thought to be the root cause of many diseases. Luckily, a high fiber intake is associated with lower inflammation and is thought to be the reason that fiber can be so helpful for a wide variety of diseases (1).
- Alters the gut microbiome
- You've probably heard of probiotics, which are beneficial bacteria that populate your gut. There is a large amount of research on how probiotics can benefit gut health and in turn benefit your overall health. Just like humans, probiotics need food to survive. This is where fiber comes in - fiber is food for our gut bacteria. So, when we eat fiber, we feed our gut bacteria, making them happy and healthy. This helps to strengthen your immune system and lower your risk of heart disease and cancer (1).
- Increased intake of vitamins, minerals, and phytoestrogens
- Most foods that contain fiber are also good sources of vitamins, minerals, and phytoestrogens, all of which can also benefit your health.
- If you’ve ever heard that a “food first” approach to meeting your dietary needs is best, this is one of the reasons. When you prioritize high quality food, you typically get more than one benefit. For example, if you ate a bowl of raspberries you would be getting an excellent source of fiber. But, because the raspberries are a whole food and not a supplement, you would also get vitamins, minerals, and antioxidants (more on supplements later).
High Fiber Diet Side Effects
Now that you know about all the great things that fiber can do for your health, you may (hopefully) be ready to jump on the fiber bandwagon with me. However, it's important to know that there can always be too much of a good thing - let's discuss.
First, increase your fiber intake slowly. Do not go from eating 5g of fiber per day to 25g of fiber in one day. This may cause stomach discomfort, cramping, constipation, diarrhea, and/or gassiness.
Second, as you increase your fiber intake also increase your water intake. As you may remember from earlier, soluble fiber absorbs water. If you eat a large amount of soluble fiber but don't drink enough water, this can cause constipation. You could also have the opposite problem where eating too much fiber causes diarrhea.
The takeaway here is to increase your fiber intake slowly and be sure to also increase your water intake. If you do experience any stomach discomfort as you are increasing your fiber intake, movement can be another way to help alleviate those symptoms.
Meeting Your Fiber Needs
Now, you may be wondering if you can just take a supplement and not have to worry about eating more plant foods. Often times when things sound too good to be true, they are. This is an example of that.
I recommend trying to meet your nutrient needs with food first. Many foods that are naturally high in fiber are synonymous with a healthy diet - fruit, vegetables, nuts, seeds, and whole grains. Simply by eating more whole foods, you will increase your fiber intake. In addition to the fiber, you will also get the benefits of the vitamins, minerals, and phytonutrients that these foods contain and that fiber supplements do not.
Fiber supplements can fill in the gaps
Even though the focus should first be on getting your fiber from food, it's not always possible to get it all from food. Supplements can be helpful to fill in the gaps. Key word here is FILL IN THE GAPS. Not, take a fiber supplement to meet all your needs and don’t worry about eating fruits and vegetables anymore.
With the increasing amount of research to support the health benefits of fiber, there has also been an increase in the amount of fiber supplements on the market. If you’ve ever been in the supplement aisle at a drug store you know what I mean when I say that it can be a confusing place! There are dozens of supplements to choose from. Unfortunately, a “fiber supplement” is not just a “fiber supplement”. There are several different types and they don’t all do the same thing. It’s important to know what goal you are trying to achieve if you choose to use a fiber supplement. Better yet, work with a dietitian or doctor to help you decide which fiber supplement would be right for you.
In the mean time, I will discuss a few of the popular supplements below.
Fiber Supplements or "Functional Fiber"
- Metamucil: this is arguably one of the most popular fiber supplements. A type of fiber called psyllium husk is the active ingredient in Metamucil. When mixed with liquid, the psyllium absorbs the water and forms a thick gel. This type of fiber is helpful for lowering cholesterol, improving blood sugar, and helping with constipation (4).
- Note: in addition to psyllium husk, Metamucil also contains artificial orange flavor and yellow 6. If you currently use or plan to use Metamucil, you can ditch these added ingredients by purchasing pure psyllium husk. If you choose to make this switch, be sure you are taking the correct dose. Also, psyllium husk on it’s own is rather tasteless so I recommend adding this to a juice or smoothie to help with the flavor.
- Note: Psyllium in one of two fibers that the Food and Drug Administration have authorized to use a health claim regarding its ability to lower the risk of cardiovascular disease by lowering cholesterol levels (the other fiber is beta glucans) (5).
- Citrucel: this supplement is made from methylcellulose, a non gel-forming type of fiber. This means it completely dissolves into liquids. This type of fiber has not been shown to lower cholesterol or improve blood sugar levels (4). Although this type of fiber may claim to help with regularity, there is no great evidence to support this (5).
- Acacia fiber: a type of fiber that dissolves well into beverages and foods (6). Studies have shown that it can help with blood sugar, increase feelings of fullness, and tends to be well tolerated even for those with IBS given that it is low in FODMAPs(6).
- Beta Glucans: another gel forming fiber and one of two fibers that the Food and Drug Administration have authorized to use a health claim regarding it’s ability to lower the risk of cardiovascular disease by lowering cholesterol levels (the other fiber is psyllium) (5).
- Sunfiber Prebiotic: Sunfiber is a brand name that uses a soluble fiber called partially hydrolyzed guar gum (PHGG) as the fiber source. Studies have shown that the PHGG found in Sunfiber can improve blood sugar, help with constipation, lower cholesterol, and help with diarrhea (7). It is rather tasteless, odorless, and dissolves well in water (8).
- Note: Sunfiber is low in FODMAPs and should be well tolerated for those with IBS.
- Benefiber: made from wheat dextrin, an artificially created fiber made by altering wheat starch (9). Some studies have shown that wheat dextrin is not beneficial for lowering blood sugar and can cause constipation.
Best tolerated fiber supplements for people with IBS: acacia fiber and Sunfiber.
Bonus: Since all of these fibers are prebiotics, they feed the beneficial bacteria in our gut, which can have a positive impact on our gut health in general.
Whole food “fiber boosters”
Like I mentioned earlier, food first is always best and by now we know that eating more whole foods is a good way to increase your fiber. However, like I mentioned earlier, even with a whole foods focus it can sometimes be difficult to meet your fiber needs. Luckily, chia seeds and flax seeds are whole food fiber sources than can help meet your fiber needs without using a supplement.
I call these seeds “fiber boosters” and like to keep some on hand at all times. I recommend using these to increase your fiber intake because they can add a decent amount of fiber to your diet without drastically changing what you are eating. And, like all plants, they have benefits that go beyond their fiber content.
- Chia seeds
- ~5g of fiber per tablespoon
- In addition to fiber, chia seeds contain omega 3 fats, which is a nutrient that many people are not consuming enough of.
- Chia seeds can absorb 12 times their weight in water, forming a gel like substance when mixed together (10). This makes it extremely important to increase your water intake when you start eating chia seeds.
- The water absorbing property is also how chia seed pudding gets its pudding like texture. When the chia seeds are soaked in almond milk overnight, they absorb the liquid and turn into a pudding-ish texture.
- I recommend keeping chia seeds on hand at all times and storing them in the refrigerator. You can sprinkle them on top of yogurt bowls, oatmeal, salads, or toast.
- Click here for my chia seed pudding recipe. This is a great high fiber, easy to make, and meal prep friendly breakfast option.
- Flax seeds
- ~3g of fiber per tablespoon
- Similar to chia seeds, flax seeds also contain omega 3 fats.
- Flaxseeds are good for constipation, preventing cancer, and lowering cholesterol, and blood sugar (11).
- You can add flax seed to smoothies, yogurt bowls, oatmeal, energy bites, and baked goods like muffins and breads.
- Flaxseeds become gelatinous when mixed with water, but not nearly as much as chia seeds. In vegan baking they are often used as an egg replacement. In fact, even if a recipe isn't vegan and calls for eggs, you can swap an egg for a "flax egg" and give your baked good a fiber boost.
- Click here to learn more about using flax as an egg substitute.
Printable List of High Fiber Foods (free download)
More Fiber Resources
- Smoothie Recipes E-Book: contains 20 healthy high fiber smoothie recipes
- Fiber Fueled
- Fiber Fueled Cookbook
- Chia seed pudding recipe
- Raspberry almond granola recipe
- Chia seeds
- Flax seeds
- Minimalist Baker: resource for plant based recipes
Disclaimer: the information in this article is for educational and informational purposes only. The information is not meant to be taken as medical advice and does not replace the advice of a medical doctor.