Soluble or Insoluble Fiber for Weight Loss? (Plus Which Supplement Is Best)

Written by Krista Bugden
Medically Reviewed by Felicia Newell, RD

January 31, 2024

Almost half of the American adult population has tried to lose weight in some shape or form (1). However, with a world bent on selling us the next quick-fix or fad diet, sustainable weight loss can feel challenging—and often unattainable at times.

But don’t lose hope yet. 

Permanent weight loss is possible, and it all comes down to the development of healthy habits that can last a lifetime. Usually, this starts with us taking a good, hard look at ourselves and being honest regarding our dietary and lifestyle choices.

Now, here’s another quick fact for you: Surprisingly, only 5% of Americans meet dietary fiber recommendations (2). So, what does this mean? 

Well, this offers a relatively easy place to start when it comes to cleaning up your diet. Below, we take a closer look at how eating more fiber can promote weight loss.

Which Fiber Is Best for Weight Loss?

“There are two types of fiber: soluble and insoluble. Both can be beneficial for health, but soluble fiber is the best choice for weight loss,” says Eva De Angelis, a Licensed Dietitian Nutritionist with The Eh Project.

What’s unique about soluble fiber is that it can dissolve or swell in water. This swelling forms a gel-like consistency similar to gelatin or jelly. This is why chia seeds, a food source that’s rich in soluble fiber, swell up when added to a liquid in your chia seed pudding recipe.

The same thing happens inside your body, too. When a fibrous food (like an orange or sweet potato) is in your intestines and comes in contact with water, a gel-like substance forms. “This helps reduce blood sugar spikes, improving blood sugar management and thus reducing fat build-up from excess sugar,” says De Angelis.

Yet, insoluble fiber can also have indirect benefits for weight loss. De Angelis elaborates further, “Insoluble fiber helps bulk up the stool and promote better bowel movements, preventing constipation. While this type of fiber does not have a direct impact on weight management, by eating high-fiber meals, you (can) reduce your overall calorie intake.” In turn, this can lead to weight loss.

Soluble fiber is also super easy to add to your daily diet. For example, foods rich in soluble fiber include apples, citrus fruits, berries, carrots, peas, chia seeds, flaxseeds, and sweet potatoes. These make for easy snacks—such as in smoothies or as toppings to Greek yogurt—or additions to your regular meals—such as adding carrots or peas as a side or mixing apples into a refreshing salad.

Meanwhile, insoluble fiber can be found in various fruits, vegetables, and nuts. In other words, adding more fiber to your diet is an easy way to add more color to your plate.

A hand pouring a scoop of NativePath Native Fiber into a glass

Restore Your Gut Health

With a slight citrus flavor, just one scoop equips you with 4 grams of Baobab and 200 milligrams of L-Glutamine to support digestion, bowel regularity, and colon health.

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Is Fiber Good for Weight Loss?

Increasing your fiber intake is an excellent addition to any weight loss journey. Here are five ways it promotes weight loss…

Fiber Has Zero Calories

Although fiber is a type of carbohydrate, there’s a big difference between it and carbs like sugar and starch. The difference, you ask?

Fiber has zero calories.

This is because our digestive system lacks the enzymes necessary to break down and absorb the components of dietary fiber (3). So fiber just passes through the digestive tract (staying relatively intact) and then gets eliminated in the stool.

Simply put, because the body can’t absorb fiber, it doesn’t contribute any extra calories to your diet. This is why it’s so beneficial to have fiber-rich greens on your plate with each meal. Consider it free calories!

Fiber Feeds Your Gut’s Bacteria

Your gut is home to over 100 trillion bacteria (4). And just like any living thing, this bacteria needs to eat—and fiber offers the perfect meal.

The bacteria in your gut are often split into two groups: “good” bacteria and “bad” bacteria. Each of us has both good and bad bacteria inside our bodies. This is normal. We just want to ensure that the bad bacteria never outweighs the good. Simply put, we want to create a diverse, well-balanced gut microbiome.

One of the ways we can achieve this is by eating fiber-rich foods (berries, oranges, and sweet potatoes), fermented foods (sauerkraut and kimchi), and prebiotic-rich foods (garlic, onions, bananas).

When you eat these foods, it feeds the good bacteria in your gut. “By fermenting fiber, they [the good and bad bacteria] produce short-chain fatty acids that have positive effects on our metabolism, body weight management, and immune health,” explains De Angelis (5).

In particular, research suggests that soluble fiber is one of the most important types to help promote a healthy gut (6).

And it doesn’t stop there…

Fiber Can Help Balance Hormones

In a 2020 review, researchers examined the relationship between obesity and the gut microbiome—and the role of probiotics, prebiotics, and synbiotics in preventing and treating obesity.

They found that when your gut bacteria is well taken care of, positive changes in hormones, neurotransmitters, and inflammatory factors start to occur (7).

For instance, hormones like ghrelin and leptin control our appetite and feelings of fullness—and researchers suggest that a healthy gut microbiome may improve obesity by regulating the hunger hormone ghrelin.

Good Bacteria Help Reduce Inflammation

Poor gut health can cause a lot of issues—including chronic inflammation

When your gut microbiome becomes imbalanced (meaning, the bad bacteria start to outnumber the good bacteria), inflammation arises (8). And when your gut is inflamed, it can be a lot harder to lose weight. Here’s why…

Inflammation—particularly in the adipose tissue (fat tissue)—can disrupt your metabolism. This disruption leads to insulin resistance and an increased storage of excess fat (9).

On the flip side, a balanced gut can lower inflammation and lead to easier weight loss and weight maintenance.

Research even shows that the introduction of prebiotics (AKA fiber) and probiotics can prevent weight gain (7). This happens due to fiber’s ability to regulate the gut microbiome and prevent food intake triggers that lead to increased weight, which leads us right into the next benefit of fiber…

Fiber Helps You Feel More Full

The undebatable truth about weight loss is that a caloric deficit is necessary to lose weight. While some may opt to count calories, this can be triggering for those who may have struggled with disordered eating or conditions in the past.

However, eating more fiber can keep you satiated, reduce your appetite, and ensure you don’t feel hungry within an hour or two after eating (10). In turn, this can reduce your frequency of snacking (or reaching for convenient and fast foods) and, thus, lower your overall caloric intake.

A woman smiling with a container and glass of NativePath Native Fiber

95% of Americans Don't Get Enough Fiber. Be the 5% That Do.

With a slight citrus flavor, just one scoop equips you with 4 grams of Baobab and 200 milligrams of L-Glutamine to support digestion, bowel regularity, and colon health.

Add to Cart

Will Fiber Supplements Help Me Lose Weight?

While whole foods are always best, if you struggle to obtain enough fiber from your diet, supplements may help.

“Fiber supplements could contribute to boosting your fiber intake and thus weight loss, but we cannot rely solely on that. By choosing to increase your fiber intake by eating more wholesome, minimally processed foods, you are improving your eating habits for the long run,” adds De Angelis.

So, what is the best fiber supplement for weight loss? 

We’re a little biased, but we recommend our Native Fiber drink mix. Its star ingredient is baobab—an African fruit that’s rich in both soluble and insoluble fiber, along with polyphenols. This unique blend can make one feel fuller, speed up the movement of food through the digestive tract, and offer antioxidant and anti-inflammatory properties.

But we didn’t stop there. We also included 200 mg of glutamine, the primary source of fuel for the cells lining your intestinal tract. This amino acid helps strengthen the gut lining, support gut health, and prevent leaky gut syndrome.

So, how do you get these benefits?

Simply add one scoop of the citrus-flavored powder to 8-12 ounces of water, stir until completely dissolved, and enjoy daily. Based on a 2,000-calorie diet, this will help you obtain at least 7% of your daily dietary needs.  On average, most women should aim to get 25-30 grams of fiber per day, while men require 35-40 grams daily (11).

Krista Bugden
Article by

Krista Bugden

Krista Bugden is a freelance writer with a BS in Human Kinetics from the University of Ottawa. She spent 5 years working as a kinesiologist, giving her the first-hand experience she needed to write well-researched, scientific, and informative blogs.

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    Medical Disclaimer

    This content is for informational and educational purposes only. It is not intended to provide medical advice or to take the place of such advice or treatment from a personal physician. All readers/viewers of this content are advised to consult their doctors or qualified health professionals regarding specific health questions. Neither Dr. Chad Walding nor the publisher of this content takes responsibility for possible health consequences of any person or persons reading or following the information in this educational content. All viewers of this content, especially those taking prescription or over-the-counter medications, should consult their physicians before beginning any nutrition, supplement, or lifestyle program.

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