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What Does Fiber Do? Soluble Versus Insoluble Fiber

What Does Fiber Do? Soluble Versus Insoluble Fiber

Read Time • 6 Min
  • Category Nutrition, Experts
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Most people think that all fiber does is help with bowel habits and not much more. Well, they are very wrong, as fiber is one component of your diet that should not be missed. In fact, most Americans fall short on taking in the recommended amounts, getting about one-third to one-half of what they need. Much research suggests that this may be a contributing factor to the obesity epidemic, the rise in heart disease and the high incidence of colon cancer.  It is about time for people to truly understand the health benefits of fiber, along with the difference between soluble and insoluble when deciding how to incorporate it into your diet.  

Related: An easy way to drive up fiber intake is by replacing some of your animal proteins with plant proteins; best plant protein sources for active people

Lets start with what fiber actually does for the body. Fiber plays a significant role in helping to lower cholesterol, keeping blood sugars stable and aiding in weight loss.  Many studies have also reported that increased amounts of fiber in the diet have been found to reduce risk factors for colon cancer.  The interesting part is that fiber is not truly digested by the human body, however it still proves to be a beneficial part of any diet. 

Not all fiber is created equal, as there are soluble and insoluble kinds. While some foods contain both types, they are typically higher in one type over another.  Having both sources in the diet are influential on the body’s overall health.  Fiber actually moves through the body slowing digestion and attaching to certain particles, then getting rid of them through your bowels.  Regardless of the type of fiber one consumes, it is always important to take in sufficient water, to keep the bowels moving. 

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When it comes to rich sources of soluble fiber, these foods tend to absorb water, changing its texture to a mushier consistency.  Soluble foods have long been found to aid in heart health, as this fiber attaches itself to cholesterol particles and then rids them from the body.  This type of fiber is also beneficial for those with diabetes, as it does not result in sugar spikes, as it is not truly absorbed during the digestive process. Those seeking to achieve weight loss or weight control find that soluble fiber is a helpful addition to the diet, as it swells and creates a sense of fullness without adding the need for additional calories.  For those hoping to regulate their bowels, soluble fibers ability to soak up water can play a key role in adding bulk to stool, to prevent constipation and diarrhea.  

When thinking of adding soluble fiber sources to your diet consider some of these healthy options:
Beans & lentils, legumes
Nuts & seeds

When it comes to insoluble fiber, these are foods that do not absorb the water and do not change texture.  Insoluble fiber has been found to play a significant role in bowel regularity, and improving how often you go the bathroom.  By adding more of this fiber, also not digested by the body, gets your bowels moving helping to prevent constipation and hemorrhoids from developing.  When it comes to weight loss and weight management, many people report that the insoluble fiber also plays a role in diminishing hunger as well. 

When thinking of adding insoluble fiber sources to your diet consider of some of these healthy options:
Whole wheat bread
Brown rice
Whole wheat pasta
Skin of fruits 

Fun high fiber recipes
Smoky Sweet Potato Wedges with Mashed Avocado
Easy, delicious, protein packed harvest bowl recipe
Fiber rich slow cooker stew (vegan or omnivore)
Healthy burrito bowl recipe - Fresh, flavorful & perfect for large groups
Protein-Packed Vegan Chili Soup
Roasted Sweet Potato, Cauliflower and Barley Salad
Maple Roasted Carrots - Easy Healthy Side Dish Recipe

It is recommended that an adult consume about 25-35 grams of fiber a day for optimal health.  This should come from a diet that contains both soluble and insoluble fiber.  It is important to also note that dietary fiber is only found in plant products, so these should be a part of a healthy diet.  

For those who are looking for ways to add fiber to their diets, some simple changes can go a long way.  One can start by swapping white breads, pastas and rice for whole grain breads and pastas, along with brown rice.  Instead of cutting off the peel to your apple or throwing away the skin to potatoes, instead eat them as well to increase fiber intake. Adding more veggies, fruits, beans, legumes and plant based foods to the diet will also add to your fiber intake. And the next time you grab a yogurt, toss in some fruit or higher fiber cereal to make it crunchy, tasty and healthier too.  With these small changes it will be easy to take in more fiber and gain the many healthy benefits that come along with it. 

Written by: M Mittler, MS Registered Dietitian