Fiber 101

Fiber 101

Most of us have heard that we should be eating more fiber to promote good health. But what does that really mean? What is fiber? What foods contain the highest amount of fiber? How much is enough and how much is too much? This article will boost your “fiber IQ” so you can optimize your fiber intake to improve your health today.

What is fiber?

Dietary fiber was defined almost 40 years ago as the remnants of plant cells that cannot be enzymatically broken down and absorbed by human digestion. Fiber refers to hemicellulose, cellulose, lignin, oligosaccharides, pectins, gums, and waxes. Instead of being digested, dietary fiber is not broken down and absorbed into the bloodstream, but instead moves into the colon where it:

  • boosts the microbiome
  • protects the colon cells
  • excretes waste, toxins, excess hormones and cholesterol

Fiber is responsible for giving plants their structure; and for humans, it’s a carbohydrate that we cannot digest or absorb. This means that unlike sugars and starches, we can’t use fiber for generating energy. Instead, dietary fiber (fiber from our food) moves through the digestive tract performing a plethora of helpful, health-promoting functions.

There are two types of fiber: insoluble fiber and soluble fiber. While they are both classified as fiber because they cannot be digested, the similarities stop there. Soluble and insoluble fiber do very different things in the body. Most grains, legumes, nuts, seeds, vegetables and fruits contain both kinds of fiber in varying amounts. 

Soluble fiber mixes with water, whereas insoluble fiber does not. Most often when you hear dietary fiber, this is referring to the fiber found in plants that make their way into your diet (aka insoluble fiber).

Functional fiber refers to fibers that have a beneficial effect on your health (aka soluble fiber), but it can also refer to extracted fibers that have been added to supplements or processed foods.

There are subcategories under each type of fiber as well. For instance, there are fermentable and non-fermentable fibers, viscous and non-viscous fibers as well as functional and dietary fibers. 

Fermentable fibers, like partially hydrolyzed guar gum (found in Florasophy), can be used as an energy source for your microbiome, meaning that it acts as a prebiotic.  The more viscous the soluble fiber, the thicker the gel is and the longer you will feel full.

It takes two to tango

For proper digestion and bodily function, you need both soluble and insoluble fiber in your diet. In fact, we recommend an even split of soluble fiber and insoluble fiber in your daily total.

Soluble fiber becomes a gel like substance in the intestine that traps toxins and wastes and moves them out of the body. It is can be prebiotic (feeding good gut bacteria) and balances the water content and consistency of the stool. 

Insoluble fiber helps to move things through the digestive track and bulks the stool. 

Working together they create the perfect "dance" of motility and consistency of stool, while soluble fiber aides in removing toxins. 

How much daily fiber should you eat?

U.S. dietary guidelines suggest that adults should be consuming a minimum of 25-38 grams of total fiber per day depending on gender and size. However, most Americans fall short, consuming an average of only 16 grams per day. While these guidelines are a good baseline, many people find that increasing fiber to between 40-60 grams per day, with an emphasis on soluble fiber (at least 15-20 grams per day), can provide extra benefit. Clinically I recommend a split of 20g of each soluble and insoluble fiber daily for a total of at least 40 grams of fiber. 

Popular diets such as keto, paleo, low-carb, and primal can provide health benefits for some people, but soluble fiber is often reduced significantly in those nutrition approaches. This is due to a restriction of grains, beans, and lentils. The truth is that fiber is a critical component of any nutritional approach, and increasing fiber through supplementation can work with and improve upon virtually any diet. 

It’s not news that we should be eating more fiber, but oftentimes, medical professionals give that advice without discerning between soluble and insoluble fiber. The reality is that they do very different things in the body and depending on what you’re trying to accomplish, you need to know the difference.

Eating a variety of fibers is key

Remember that it's vital to eat a variety of fibers. Not all fibers provide the same benefit, so just like mixing up your veggies each day, focus on eating a diversity of fiber as well. Studies show that adults often thrive on at least 40 grams of fiber each day, with about half of those grams coming from soluble fiber. To reach your daily fiber goals, make sure to eat a mixture of beans, lentils, chia, flax, avocado, oats, Brussels sprouts, and sunflower seeds. 

It can be tough to reach 20 grams of soluble fiber each day with food alone. A daily dose of Florasophy can boost your soluble fiber intake by 4-12 grams per day! It’s a perfect insurance policy to keep you on track to reap all the health benefits of soluble fiber.

About Megan Barnett, MS, CNS

Megan Barnett, MSMegan Barnett is a functional medicine practitioner in Portland, Oregon. In her clinical practice, she helps patients identify the root cause of their health problems, then designs individualized and evidence-based approaches to alleviate symptoms and help their bodies heal. She has a Bachelor of Science in Dietetics from Kansas State University and a Master of Science in Nutrition and Functional Medicine from University of Western States.