What Is The Best Fiber Supplement For Keto? Product Guide And Review

It is common to neglect the necessary fiber your body needs when committing to a ketogenic diet. Having sufficient amounts of dietary fiber can help correct bowel movements, improve digestion, and help you stay more full throughout the day.
Since following a keto diet requires you to choose foods that are high calorie and contain low carbs, you may find it challenging to get enough fiber in your diet from whole foods. This is where supplementing your fiber intake can help.
"This site contains affiliate links to products. We may receive a commission for purchases made through these links."

In this complete guide and review, we will be looking at why including fiber to your diet is important, as well as the health benefits it offers. We also reviewed top products to find the best fiber supplement for keto.

Let’s dive right in!

In A Hurry?

Here are our top 3 fiber supplements for keto, at a glance!




2nd Place



3rd Place

Ancient Nutrition




Organic Acacia Fiber

NOW is a family-owned company that has been operating in Canada and the US since 1968. This soluble fiber supplement is sourced from acacia trees which helps to lower insulin and bad cholesterol. It only has 25 calories and 6g of net carbs, making it a reliable choice for your ketogenic diet.
This fiber supplement also has a USDA organic certification, is non-GMO verified, and doesn’t contain any synthetics, so you never have to second guess what is going into your body. It is also gluten-free and vegan-friendly since it is 100% plant-based. 
Lastly, the supplement has no flavor, allowing you to mix it with anything you like without compromising taste.

What Customers Are Saying

Many customers who used this product said it helped reduce bloating and constipation. The only complaints that were reported were the powder not dissolving well in cold liquid. However, using a blender will solve the problem if you want to mix it with a cold beverage such as water or juice.




Natural Organic Flaxseed Fiber

This fiber supplement is sourced from organic flaxseed that is cold-milled to maintain its freshness. A lot of attention is given to the manufacturing process, such as making sure the seeds are not broken to help maintain quality and its nutritional value. Flax-seeds are also high in omega-3 fatty acids which are essential for healthy eyes, immunity, brain, and skin
This fiver supplement is certified organic, non-GMO, kosher friendly, and is gluten-free. It contains 4g of carbs and only 6g of fat per serving, making it ideal for weight loss. The blend is also completely tasteless so you don’t affect the flavor when mixing it with your favorite beverage or meal.

What Customers Are Saying

Customers who use and purchased this fiber supplement expressed high compliments in regards to the freshness once opening the packaging. Many reported a significant improvement with constipation and overall digestion when following a keto diet.



Ancient Nutrition

Keto Fiber

Ancient Nutrition is a fiber blend formulated by the famous Dr. Josh Axe who has quite a reputation when it comes to quality health products. This fiber supplement is both soluble and insoluble to improve overall digestion health. The fiber is derived from chia seeds, flax seeds, and cinnamon which are all a great source of natural energy.
A unique feature about this fiber supplement is its boosted with MCT’s (medium-chain triglycerides). These types of healthy fats are stored differently in the body and are broken down easier, therefore promoting weight loss. 
The formula is also rich with antioxidants that help fight off free radicals which can be linked to life-threatening diseases including cancer.

What Customers Are Saying

Customers reported this fiber to digest very well. On the downside, the formula does not dissolve completely in thick liquids such as milk.



NOW Psyllium

Fiber Husk Powder


This unique fiber supplement is sourced from psyllium husk seed. It contains 6g of soluble and 1g of insoluble fiber which helps support gastrointestinal function and improves bowel controlIt has 8 carbs and is both vegan and kosher verified, and doesn’t contain any GMO’s or synthetics in order to maintain its purity and quality. 

On the downside, Psyllium husk seed does contain high amounts of sodium, so don’t be surprised to see the 10g per serving in this fiber supplement.

What Customers Are Saying

Customers said this fiber helped reduce gas, however, the powder does not mix properly and is clumpy. We recommend blending it or mixing it in a shaker if you are going for this product.




Prebiotic Fiber Supplement

Benefiber offers 125 servings of 100% pre-biotic soluble fiber which increases the number of good bacteria for healthy digestion. The ingredients are derived from wheat dextrin, containing only 4g of carbs and 0 sugar content.
This is a great fiber supplement for improving bowel control and reducing constipation. The powder is also tasteless, so you can mix it with anything you want without affecting the flavor. Benefiber also has packets available if you want to take your fiber with you on the go.

What Customers Are Saying

Most customers on a keto diet said that this product did in fact help with bowel control, as well as reducing constipation. However, a few reported no difference at all. 



Our Choice And Why

It is important to stay careful when choosing fiber supplements so that you do not compromise your ketogenic diet. You want to choose a product that is low in carbs and can help you improve digestive health, a well as resolving any digestion challenges you may face by helping you meet your daily fiber intake.

Our best fiber supplement for keto is the NOW Organic Acacia Fiber Supplement. It only contains 6g of carbs as well as 6g of soluble fiber which is a sufficient amount for anyone who is on a keto diet. 

Simplicity is king here, and we love how this product sources high-quality fiber using only one ingredient, acacia senegal. The powder can be mixed with anything and simply does the job of promoting good digestion health and improving bowel control. 


​Dietary Fiber 101

Fiber is a nutrient source which primarily comes from plant foods. It travels through our digestive system and absorbs water along the way in order to ease bowel movements through your digestive tract.
Dietary fiber is not absorbed by the body, but instead, stays intact when traveling through your large and small intestine. People often turn to fiber when trying to correct bowel problems, or if they want to stay fuller for longer between meals.
Dietary fiber is classified into two segments, soluble and insoluble fiber.
Soluble fiber: This classification of fiber dissolves in water and forms a more diluted substance. It helps to lower cholesterol in the blood, as well as glucose levels which are associated with cardiovascular disease.

Foods that contain soluble fiber include:

  • Peas 
  • carrots
  • citrus fruits
  • oats
  • apples
  • barley
Insoluble fiber: Helps to push other materials through your entire digestive system. If you struggle with constipation or irregular bowel patterns, this type of fiber will help improve digestive health by normalizing its overall function.

Food sources that contain insoluble fiber include:

  • Green beans
  • potatoes 
  • vegetables
  • beans
  • nuts
  • whole wheat foods

The Health Benefits Of Eating Fiber On A Ketogenic Diet

Food containing natural dietary fiber, healthy nutrition concept

Dietary fiber contains many health benefits and is one of the reasons why many people turn to plant based foods and look to lean on a fiber supplement for its properties.

Below is a list of some key benefits of adding fiber to your keto diet:

Can Reduce Insulin Spikes

High fiber foods tend to have fewer amounts of glucose levels than non-fiber foods. Too much glucose in your blood can often lead to life-threatening health complications, including type 2 diabetes and heart disease

Can Reduce Cholesterol

Fiber that has a higher viscosity helps to reduce cholesterol levels. Studies have shown that people who eat more fiber tend to have a lower risk of experiencing heart disease later on in life.

Helps Reduce Constipation

One of the most known benefits of dietary fiber is it helps reduce constipation by improving overall digestive health. This is a common problem for those who commit to a keto diet because your body is digesting more fats.

Fiber absorbs water, therefore increasing the bulk of your stool (or poop) and also speeds up the movements of your intestine. This helps push out any material passing through your digestive system.

Helps With Weight-Loss

Because fiber is not absorbed by your body, it can help reduce your appetite by helping you stay full longer between meals. This reduces the number of calories you consume, thus promoting better weight loss and weight management results
The best type of fiber that helps aid in weight-loss, regardless if you are on a keto diet or not, is soluble fiber. This is because it helps you stay fuller longer because it soaks up water in the intestine, therefore reducing the amount of time your body takes to absorb nutrients.

May Help Prevent Colon Cancer

According to research done by Healthline, colorectal cancer is the third leading cause of cancer deaths in the world

Whole plant-based foods that are high in fiber contain antioxidants and phytonutrient properties. These help to eliminate free radicals that increase the risk of life-threatening diseases, including cancer

Fiber And Ketogenic Dieting

If you are just getting started with keto dieting, then the rules are simple. 
A keto diet requires you to consume high amounts of healthy fats and focus on low carb consumption. Therefore, it is very easy to neglect your fiber intake in your diet. Not getting enough fiber from foods such as vegetables and nuts can also lead to a lack of micro-nutrients, which are essential for your organs and body.
Focusing on fatty foods can make it challenging to add leafy vegetables and high fiber foods to your meal. High-calorie foods already make you full as it is, which is why taking enough fiber by supplementing, can help.
If you are on a ketogenic diet, you may or may not have already experienced a change in bowel movements. Ensuring you have enough fiber in your diet will help you correct digestion and avoid constipation.

How Much Fiber Should I Eat On A Keto Diet?

To avoid constipation when on a ketogenic diet, you must make sure that you have a good fiber to calorie ratio. The Academy Of Nutrition and Dietetics recommends a daily fiber intake of 25g for women and 38g for men.
Although this is a good rule of thumb, many people who have been successful following their diet recommend aiming anywhere between 15-25 grams of fiber for every 1000 calories

How Much Fiber Is Too Much?

Because fiber absorbs water and is not taken in by your body, you may experience bloating, gas, and even constipation. Large fiber intake can actually slow down the materials passing through your digestive system and may cause stomach cramps, aches, and pains.
These side effects can occur if you intake 70 grams of fiber or more. Depending on several factors including age, weight, and health, some people may experience negative side effects after taking just 40 grams.

To determine the best amount for you, start off with a minimum of 15g per 1000 calories, then slowly increase the dosage until you find an adequate amount. If you are taking a fiber supplement, then you can cut your intake in half and then gradually up your amount.

If you want a more in-depth guide on how to get enough fiber and how much you need per day, you can read this article. The information there is relevant for any kind of dieting plan, including the keto diet.

How To Choose The Best Fiber Supplement For Keto


Like making any purchasing decision, quality is priority when looking for the best fiber supplement for keto.

You should never neglect quality when choosing products that go into your body. I always prefer brands that grow their resources organically and do not contain any GMO’s or synthetics.

It is common to see brands making big claims about how the product can help customers. Third-party certificate stamps on the label are a good indicator that any claims stated are in fact true and regulated

Labels such as NSF, Certified Organic, or FDA Certified are all good signs that you should look out for.


When choosing a fiber supplement for a ketogenic diet, make sure to look at what foods the fiber is derived from. 

You want to focus on soluble fiber foods which can be found in seeds, beans, and green vegetables. These sources are low in cholesterol and saturated fats and won’t compromise your keto diet.


It’s always a good idea to plan ahead and write down what dosage amount you want to take so that you are getting enough fiber in your keto diet. 

Calculate how much supply you will need when choosing your fiber supplement, and make sure it meets the minimum requirements for your specific gender and ageAlso, consider any other sources of fiber you may be eating outside of supplementing when following a ketogenic diet.