Best Fibre Supplement for Ketogenic Diet

 

The keto diet focuses on high fat, moderate protein, and low carbohydrates, slowing digestion and making it challenging for people to get sufficient fibre intake. Thus, fibre is essential for digestive health in high-fat diets, especially the keto diet. 

The keto diet limits net carbohydrate intake (net carbohydrates minus fibre), up to 20 to 25 grams as compared to a typical carb intake of 150-350 grams. Total carbohydrates include all carbohydrates in a food (sugar, starches and fibre), while net carbohydrates involves subtracting fibre and sugar alcohols from total carbohydrate intake. The sudden reduction of carbohydrates forces the body to switch its fuel source from glucose (sugar) to fatty acids. Thus, the diet was designed in 1920 to provide many health benefits, such as weight loss and improved blood sugar and cholesterol levels.

Although there are many health benefits, there are certain risks associated with a ketogenic diet. One of the greatest challenges is getting enough fibre, which causes regulatory changes. A common phenomenon that people experience while following a keto diet is constipation. It results from a diet low in fibre that causes hard, stubborn stools and bloated guts. 

To avoid such complications, adding a fibre supplement is a great way to add fibre to the ketogenic diet. While following a keto diet, it is essential to choose keto-friendly supplements that are free of sugar and gluten to align with the principles of a diet. 

As a fibre supplement for a ketogenic diet, psyllium husk powder (like Metamucil Sugar-Free) is a good choice because it is low in sugar and protein and high in fibre. People can also consume natural fibre sources that are compatible and keto-friendly, such as acacia fibre and flaxseeds. 

Consuming a sufficient intake of fibre is essential for digestive health. As the fibre is not digested by the body, it passes through the system, softens the stool, and adds bulk. Fibre is not beneficial for bowel movements only; it also feeds good bacteria in the GI tract and aids in healthy digestion and improved nutrient absorption.

The Role of Fibre Supplements in a Ketogenic Diet

Fibre is essential in a ketogenic diet for the prevention of constipation and to support digestive health. However, keto restricts high-fibre foods like grains and legumes that contribute to a healthy gut microbiome and overall well-being. 

1. Net Carb Management

The term "net carbohydrates" refers to the carbs that are absorbed by the body when consumed. To calculate the net carbohydrate in whole foods, take the total number of carbs and subtract the fibre grammes. Fibre is different from other carbs in terms of digestion and how it affects the body. The small intestine does not absorb natural fibre like it does starch and sugar. 

In the keto diet, carbs are usually limited to 20 to 50 grams per day. While some people on keto count their total carbohydrate intake, others count net carbs. The term "net carbs" means "total carbs minus fibre." The Dietary Guidelines for Americans by USDA 2020–2025 set a goal of consuming 28–34 g of fibre a day, depending on age and sex. The National Institute of Health also recommends consuming 25g of fibre for women and 38 g for men daily. 

On a keto diet, a lack of sufficient fibre causes constipation. Long-term constipation also leads to anal fissures, severe abdominal pain and hemorrhoids. People who are new to the keto diet may face constipation from a few days to a few weeks. As the body adapts to digesting more fats and fewer carbohydrates, the constipation may improve with time. If the constipation lasts longer, try these home remedies for better relief.

• Drink more water.
• Consume extra fibre-rich foods in a diet, such as leafy greens, broccoli, nuts, seeds, and berries.
• Go for a brisk walk after meals.
• Try bowel training (a method to pass stool at the same time every day)

1. Gut Health & Ketosis: 

Fibre is necessary for promoting gut health. It adds bulk to stool and relieves constipation. It is also essential to maintain ketosis because fibre remains undigested and does not count as a net carb. Fibre is indigestible and doesn’t contribute to net carbs; it also does not directly increase blood sugar levels. In the gut microbiome, it serves as a food source for beneficial gut bacteria, which is essential for digestion, nutrient absorption, and immune function.

1. Product Examples: 

There are many product supplements available online that are keto-friendly, low in carbs and high in fibre. Examples of these supplements include inulin fibre, gum arabic, and psyllium husks. Another supplement is Renew Life Adult Completely Clear Organic Prebiotic Keto Friendly Fibre Powder, a 7 oz pack easily available at Walmart, that ensures soluble adult prebiotic fibre suitable for both men and women.

1. Digestive Adaptation: 

In a keto diet, gradually increase the amount of fibre for digestive adaptability. To avoid bloating in a ketogenic diet, slowly add fibre to a diet and consume a sufficient amount of water. The Healthline also highlighted starting with a daily carb intake of about 50 g and then slowly reducing the carb intake as the digestive system adjusts to reduce the symptoms of bloating and constipation. This method takes time to reach ketosis but is helpful to stick with a diet for a longer time with fewer side effects.

1. Blood Sugar Stability: 

Fibre plays a major role in regulating blood sugar levels. When soluble fibre dissolves in water, it forms gel-like substances that slow down the digestion process and make it harder for enzymes to break down glucose, which lowers sugar levels in the blood. The CDC also highlighted that soluble fibre is beneficial for reducing blood sugar and leads to a 15% reduction in glucose spikes.

Types of Fibre: Soluble vs. Insoluble

There are two types of dietary fibre: soluble and insoluble. Both types of fibres are unique, essential for digestion, and provide many health benefits.

• Mechanism of soluble fibre: Soluble fibre is a type of fibre that attracts water and forms a gel-forming consistency in the intestines and slows down the digestion process. The National Lipid Association also highlighted that consuming 5-10 g of soluble fibre in a day lowers 5-11 points of LDL cholesterol and more.

• Insoluble fibre: Insoluble fibre does not dissolve in water and passes undigested through the intestine, forming bulk. Insoluble fibres are beneficial for relieving constipation and improving digestion. It is insoluble in water and attracts water into the stool to soften the stool and make it easier to pass with less strain on the bowel.

Which fibres are suitable for a ketogenic diet?

In the keto diet, focus on insoluble food sources such as leafy greens, broccoli, cauliflower, nuts, seeds (chia, flax, pumpkin), and psyllium husk. It also contains some soluble fibre from vegetables and berries, which is beneficial for improving overall health. 

A study published in PubMed journal titled “Role of Short-Chain Fatty Acids in Inflammatory Bowel Disease” showed that gut bacteria and short-chain fatty acids that make more butyrate are linked to a 20% drop in colon inflammation. This is because butyrate has anti-inflammatory properties.

The USDA's 2020–2025 Dietary Guidelines for Americans recommend consuming 28 to 34 g of fibre, but in the ketogenic diet, it is essential to maintain fibre intake up to 25-38 g per day, prioritizing low-carbohydrate sources. 

Soluble Fibre and its Benefits

Soluble fibres are mostly found in plant-based foods. It is beneficial in forming bulk stools, improving bowel regulation, and relieving diarrhoea.  The other benefits of soluble fibre in the keto diet also include

• Lowers LDL cholesterol: Soluble fibre also binds with cholesterol and lowers LDL (bad) cholesterol in the digestive tract by removing it from the body. Some types of soluble fibre are also known to lower the risk of heart disease. 
• Promotes regularity: Soluble fibre promotes regularity by softening stools and supporting regular bowel movements. 
• Improved gut health: Soluble fibre improves gut health by forming a gel-like consistency that feeds gut bacteria and slows down the digestion process. 
• Sources of soluble fibre: Sources of soluble fibre include oat bran, barley, nuts, seeds, beans, lentils, peas, and some fruits and vegetables. It is also found in a common fibre supplement, known as psyllium. 

• Prevention of blood sugar spikes: When digestion becomes slower, it controls blood sugar and cholesterol levels. The soluble fibres do not provide calories and glucose for energy, which prevents sudden blood sugar spikes.

Insoluble Fibre and Its Role in Digestion

Insoluble fibre is also beneficial in supporting bowel movements and preventing constipation.

• Supports Bowel Movements: Insoluble fibre adds bulk to stools and stimulates the digestive tract. It speeds up the digestion process and promotes regular bowel movements.
• Preventing Constipation: People on a keto diet commonly experience constipation due to slower digestion. Insoluble fibre acts as a brush to remove waste products in the digestive tract without dissolving in water and thus prevents constipation. 
• Gut Health: Insoluble fibre also supports intestinal gut health by regulating digestion, relieving constipation and preventing hemorrhoids.
• Sources of Insoluble Fibre: Some sources of insoluble fibre in the keto diet include broccoli, brussels sprouts, bell peppers, flax seeds, chia seeds, avocados, almonds, spinach, asparagus and green beans.
• Solving Keto Digestive Issues: Many beginners on a ketogenic diet experience constipation. Insoluble fibre is beneficial for resolving digestive issues because it adds bulk to stools, which prevents constipation. Insoluble fibre also addresses irregular bowel movements that are linked with immune function and supports mental health and disease prevention. 

Top Keto-Friendly Fibre Supplements

Below is a list of fibre supplements that provide many health benefits and are keto-friendly. 

1. Renew Life Superfood Organic Prebiotic Fibre: 

It is the best keto-friendly fibre supplement to consume, with 100% soluble fibre available in powder form. It includes whole fruits and vegetables, such as spinach and kale, which give antioxidant power. The organic prebiotic factor uses resistant tapioca dextrin, which is low in carbohydrates and makes it ideal to consume in the keto diet. This supplement powder is gluten, dairy and soy-free to meet the daily dietary requirements. The 7-ounce RenewLife serves 30 with 6 grams of fibre and costs only $22.29.

 

 

1. Bellway Super Fibre + Fruit:

It is another keto-friendly gentle fibre supplement that is low in net carbs, relieves bloating and reduces constipation and diarrhoea while maintaining a healthy gut microbiome. It is not only keto-friendly but also suitable for vegetarians and vegans because it is a gluten-free and sugar-free supplement and does not contain aspartame. Bellway Super Fibre + Fruit weighs 13.7 oz and gives 50 servings with 5 g (18% DV) fibre per serving. It is a budget option that costs only $29.99.

1. Psyllium Husk:

Metamucil Sugar-Free Orange Smooth Powder contains psyllium husk fibre, which is keto-friendly if consumed with enough fluid. It is also gluten-free and beneficial for controlling appetite, maintaining blood sugar levels, and lowering cholesterol.

It also minimises the risk of cardiovascular problems and prevents constipation. People allergic to psyllium should avoid this supplement as it may trigger severe allergic reactions in sensitive individuals 1.04 kg of Metamucil Sugar-Free Orange Smooth Powder serves 180 and gives 3 g fibre (11% DV) per serving for only $32.98.

1. Acacia Fibre:

Acacia powder is harvested from acacia trees, originating from parts of Africa and Asia. Now Foods Acacia Powder is another prebiotic supplement that supports a healthy GI environment. It is a keto-friendly supplement that serves 6 g and provides 6g of carbohydrates and 25 calories. It is free from yeast, wheat, gluten, soy, corn, shellfish, or tree nut ingredients, which makes it safer to consume for allergic or sensitive people. 

1. Flaxseed: 

BSL Organic Ground Flaxseed is another nutritional supplement with no chemicals or additives added. The powder is a great source of plant-based proteins and ideal to consume for people following a keto-friendly, low-carb, and gluten-free diet. The powdered supplement is available in 7 and 13 ounce pack with zero trans fat and sugar, rich in fibre and omega 3 fatty acids.

1. Resistant Tapioca: 

Resistant Topioca is a dextrin type of dietary fibre derived from organic starch. It is labelled as non-GMO and safer to consume. Non-GMO verified and generally recognized as safe (GRAS) by the FDA. The colour appearance of dextrin is white to light yellow powder with sweet, mild or pure flavour taste. It acts as a prebiotic, feeds beneficial bacteria and promotes healthy digestion. It also slows down the absorption of sugar, prevents sugar spikes and supports healthy blood glucose levels with enhanced nutrient absorption.

Key Considerations When Choosing a Fibre Supplement

Below are some guidelines to choose the best fibre supplement while following a keto diet. 

 

1. Low-Carb Content: Before purchasing a fibre supplement, check the ingredients carefully and choose a keto-friendly option. Ensure that the supplement doesn't contain high carbohydrates and exceeds the requirements.
2. Sugar Alcohols: Some sugars, such as maltitol, are not keto-friendly and have a pronounced effect on blood sugar levels and should be limited in the keto diet. So, always consider sugar-free formulations for the keto diet. 
3. Form Factors: Consider capsule or powder depending on personal preferences. The majority of people prefer to choose powder for supplements. Powders are more convenient for fibre supplements as they provide dosage flexibility and are easier for those who struggle with pills.
4. Fibre Type: In a keto diet, both soluble and insoluble fibres are beneficial. However, soluble fibre is preferable to insoluble fibre because it manages gut health, especially constipation and diarrhoea.
5. Allergens: For people with dairy and gluten intolerance, choose alternertaives such as inulin, psyllium (Metamucil, Konsyl, others) and methylcellulose (Citrucel) that are free from allergic substances and safer to consume. 
6. Dosage Timing: It is preferable to take fibre supplements in the morning to control appetite, weight loss and optimal gut motility. However, it can be taken at any time. Also, ensure that the supplement fits with daily fibre goals without overconsumption.
7. Water Intake: It is essential to drink sufficient fluid with fibre supplements to prevent discomfort and constipation. Insufficient water with fibre supplement may cause the supplement to swell and could cause choking. 
8. Healthcare Consultation: It is essential to consult with healthcare before taking any fibre supplements. Fibre supplements may interact with other medicines, such as metformin or thyroid medicines, which affect the absorption of supplements.

Benefits of Fibre Supplements in a Keto Diet

Consuming fibre supplements on a keto diet has the following benefits:

1. Weight Loss: Fibre plays a major role in weight management. Healthline also highlighted the beneficial effects of glucomannan, a keto-friendly soluble fibre extracted from konjac roots. It is viscous and shows visible results in weight reduction in obese and overweight people. Fibre helps curb hunger, thus supporting ketogenic weight loss goals.
2. Butyrate Production: The intake of fibre supplements in a keto diet increases the growth of beneficial gut bacteria. The supplements make it easy to meet the fibre requirements without consuming high-carbohydrate foods in a keto diet. A study published in PubMed Journal: titled: The ketogenic diet: its impact on human gut microbiota and potential consequent health outcomes: a systematic literature review” also highlighted the findings of its research and concluded that a ketogenic diet significantly reduces short-chain fatty acid production.
3. Cholesterol Impact: The American Journal of Clinical Nutrition also highlighted the positive impact of dietary fibre supplements for lowering LDL cholesterol. The FDA approved a health claim for a fibre intake of 4 cups daily because it lowers the risk factors related to blood lipids for cardiovascular disease. The National Lipid Association also concluded that eating 5 to 10 grams of soluble fibre a day can help lower total and LDL cholesterol by 5 to 11 points.
4. Appetite Control: Soluble fibre controls appetite by increasing feelings of fullness (satiety) and slowing down the digestive process. It results in reduced caloric intake and a feeling of satisfaction for longer. The NIH also highlighted that soluble fibre delays gastric emptying, which prevents bloating or discomfort from changing dietary habits.
5. Microbiome Diversity: The NIH also highlighted that when a small amount of fibre was added to low-fibre and low-carb diets, it resulted in an increased relative abundance of the beneficial gut microbial genus Bifidobacterium.

Natural High-Fibre Foods for Keto Diet

Below is a list of naturally high-fibre foods that are beneficial to consume on a keto diet.

1. Chia Seeds:

Chia seeds are smaller in size but rich in several nutrients. It is the best source to get a high amount of fibre, protein, vitamins, minerals and omega-3 fatty acids. According to the USDA, one ounce of chia seeds contains 9.6 g of fibre and 2.2 g of nett carbohydrates. It can be consumed with liquid or used as a natural sweetener like honey. Sprinkling chia seeds into low-carb smoothies or oatmeal, eggs or salad makes a perfect combination to consume in a keto diet. 

1. Avocados: 

Avocados are a great source of fibre and fatty acids. It gives a unique buttery texture when combined with vegetables. According to USDA, the avocado contains 7g of fibre and 2 g of net carbohydrates. It is ideal to eat avocado in a keto diet because it is also rich in monounsaturated fat, folate, potassium, vitamin C and K.

1. Coconut:

Coconuts are also low in carbohydrates and high in fibre. It is perfect to maintain ketosis because half a cup of dried unsweetened coconut gives 7 g of fibre and 3 g of net carbohydrates. On a keto diet, it can be consumed as a snack and adds texture and flavour to plain Greek yoghurt. 

1. Broccoli: 

Broccoli is another popular cruciferous vegetable. It is high in fibre and provides several vitamins and minerals, including potassium and vitamin C. It is a keto-friendly food that gives 5 g of fibre and 6 grammes of net carbohydrates in 150 g of cup.

1. Flaxseeds: 

Flaxseeds are small oil seeds, packed with various essential nutrients. They are a good source of omega-3 fatty acids, fibre and antioxidants. The USDA reports that 1 tablespoon (tbsp) of ground flaxseeds provides 2 g fibre and 0 g net carbohydrates which makes it a keto-friendly to consume. 

 

Supporting Weight Loss and Managing Constipation

The keto diet supports weight loss and better management of constipation, as they are two major concerns for keto diet followers. 

• Satiety and Fullness: Dietary fibre ensures metabolic health benefits and supplementation in a keto diet is beneficial to curb appetite. The supplements ensure a feeling of fullness that results in lower calorie intake and, thus, supports weight loss goals.
• Relieving Constipation: In the keto diet, many high-fibre foods, including fruits, vegetables, and grains, are restricted, which causes constipation in the majority of people. Consuming insoluble fibre supplements is an effective way to relieve constipation caused by a keto diet.
• Digestive Comfort: With multiple restrictions in the keto diet, fibre supplements make the transition process of the diet smoother by reducing bloating and digestive discomfort. These supplements also help people stick with a diet for longer. 
• Keto Adaptation: In keto adaptation, both soluble and insoluble fibres are beneficial for adjusting the body to follow a ketogenic diet without causing digestive issues. Soluble fibre dissolves in water and forms a gel-like consistency, which slows the digestion process. Similarly, insoluble fibre adds bulk to the stool and relieves constipation. 
• Consultation with Healthcare Providers: Although fibre supplements are beneficial in the ketogenic diet, it is recommended to consult professionals before starting new supplements, especially for those with other medical conditions. 

Conclusion

Fibre supplementation showed a positive role in the overall ketogenic diet. Always check the ingredient list and choose supplements that are sugar-free with low net carbohydrates to align with the principles of the keto diet, such as wheat dextrin and acacia. To avoid gastrointestinal problems such as constipation, bloating, and diarrhoea while transitioning, gradually increase the number of dietary fibre supplements. For effective results, you can also pair fibre-rich supplements with keto-friendly whole foods, such as avocados and chia seeds. The National Institute of Health (NIH) recommends a daily fiber intake of 25-38 grams, depending on age and gender, with 25 grams for women and 38 grams for men. Therefore, if you experience chronic constipation while following a ketogenic diet, we recommend consulting a dietitian or healthcare professional.