NutritionWhat Does Fiber Do? (Part 2) Soluble Fiber Deep Dive

November 1, 2021by Mike Phoutrides0

If you’re not one for detail, this blog post is not for you, so feel free to say no to this one, however if you have read What Does Fiber Do? (Part 1) and want to dive deeper into dietary fiber this is for you!

This blog post is part two of a three-part deep dive into dietary fiber. The one you’re reading now is on soluble dietary fiber. 

First things first, how is this deep dive into soluble dietary fiber going to help for weight loss?

The more implementable knowledge you have the better. This is going to sound self-serving, but the mission of Cornerstone Weight Loss is to help you better understand how food affects your body in a common sense way that will put you in control of how you look.

You can definitely get to your weight loss goals without these dietary fiber deep dives, but the further you go into the “why” the more equipped you will be to have the control of the looks and weight that you desire to have. (Not to mention you can pass this on to your friends and family and be that knowledgeable, helpful hero you’ve always wanted to be)!

What happens when we eat dietary fiber?

This is a great place to start! 

First things first, dietary fiber is a carbohydrate. Unless you’re eating pure glucose, most carbohydrates you eat are bound together chemically by glycosidic bonds. For example, the sugar you put in your coffee (your secret is safe with us) is actually called sucrose, which is just a glucose molecule and a fructose molecule bound together by a glycosidic bond. Your saliva and small intestine will contain the enzymes (proteins) needed to break that glycosidic bond; this frees the glucose and the fructose molecules so they can be absorbed by your body. 

Dietary fiber is a little different. It is constituted of single sugars (just as sucrose is constituted of single sugars), however the way in which those single sugars are bonded changes things up a bit. Dietary fiber cannot be broken down into its single sugar parts because we just don’t have the enzymes to get the job done, which is why dietary fiber is considered indigestible.  

So what’s solubility all about anyway?

Solubility is about water. 

Soluble dietary fiber is dissolved in water. Leaving out the soluble dietary fiber used for pre-biotic supplementation, soluble dietary fiber when dissolved in water forms a thick, sticky gel in the large intestine. (Here’s a nice breakdown of digestion for you). If this soluble dietary fiber is fermentable, that gel will be metabolized by the microbiome in your large intestine, and if this soluble dietary fiber is non-fermentable it will retain its thick, sticky gel form. The latter (non-fermentable) is what helps keep your stools regular by retaining the previously absorbed water, reducing the likelihood of stool becoming dehydrated and hardened.  

If soluble dietary fiber is indigestible, where do the calories come from?

To answer this question, let’s get past what the digestive system is doing and look at what the inhabiters of the digestive system are doing. At the end of the digestive road is the colon, and its home to microflora, or bacteria, that thrive on the end result of digestion. 

These can do something with the dietary fiber the body cannot, pretty cool. These bacteria can ferment the undigested soluble dietary fiber and the end result are short chain fatty acids, or SCFAs for short. Cells in the brain, colon, and liver can use these SCFAs for energy, which is why an indigestible molecule is counted in our overall energy balance when consumed. Interestingly, different soluble dietary fiber sources provide varying amounts of fermentable material, so not all sources of soluble dietary fiber actually yield the same amount of overall energy as one another. According to the study The Role of Fiber in Energy Balance by Hervik and Svihus, the caloric value that is given to fiber on nutrition labels of 8 kj (1.9 kcal) is “an average, at best.”

If you’re a diligent macronutrient and calorie tracker that last statement may have sounded scary. You may even have started thinking you need to revamp the way you track because you may have been doing it wrong all along. For the record, nutritional labels are averages, not much is totally accurate, so it seems best not to fret!

What else does soluble dietary fiber do for overall heath? 

It seems like a poor idea to gloss-over the research that dietary fiber benefits many health markers in including but not limited to total cholesterol, glycemic control, blood pressure, and so on. Additionally, dietary fiber has been seen to aid in some prevention of cardiovascular disease, Type 2 diabetes mellitus, metabolic syndrome, and some cancers. See the Linus Pauling Institute’s article, Fiber here.* 


Understanding soluble dietary fiber’s role in your overall diet is an important step for longterm weight loss. As good researchers and practitioners of weight loss, we must continue to ask deeper questions of soluble dietary fiber’s role in hunger satiety, overall caloric restriction, and digestion. As a matter of opinion, there is enough anecdotal success observed in clients, as well as peer-reviewed scientific studies, to recommend no weight loss program goes without it. As more curious and honest researchers study this important macronutrient, Cornerstone Weight Loss encourages comments, further evidence, anecdotal experiences, and questions, so feel free to comment below and email

The more we understand the role of soluble dietary fiber, the further we can help others better understand how food affect their bodies in a common sense way that will put them in control of how they look.

In order to get in touch with a professional who can help tailor your weight loss plan to you, click below, fill out the information, and a member of the Cornerstone Weight Loss team will reach out to you to get the results in weight loss you deserve.

*This link leads to a website provided by the Linus Pauling Institute at Oregon State University.  Cornerstone Weight Loss is not affiliated or endorsed by the Linus Pauling Institute or Oregon State University

Leave a Reply

Cornerstone Weight Loss is a leading health and nutrition training company that helps people better understand how food affects their body in a common sense way that puts them in control of how they look, forever.
25 N Belcher Rd APT B30
Clearwater, FL 33765

8am to 5pm M-F
(727) 605-1841

To empower you with a clear understanding of how food uniquely affects your body, in a common sense way, that enables you to have complete control over how you look - for life.

Ready To Take Control of Your Weight?

Set yourself up for success with “The 5 Steps to Make Sure You Don’t Kill Your Weight Loss Plans Before They Begin”. Download today!