Keto Constipation: What Causes It and How to Fix It

The keto diet is undoubtedly healthy for many reasons. This is especially true if your goal is weight loss, improved blood glucose balance, enhanced energy levels, or boosted cognitive function.

However, cutting out carbs and loading up on healthy fats can also cause some side effects and symptoms, particularly a phenomenon known as keto constipation.

Constipation can be a tricky condition to treat since there is a multitude of things that can cause it. In general, though, your diet is the biggest factor for determining the frequency (or lack thereof) and characteristics of your bowel movements.

If you’re not careful about the specific foods and nutrients you consume, then indigestion and micronutrient deficiencies become more common. This may cause constipation. But that’s not all, as a variety of other factors play into keto constipation.

This article will dive into what keto constipation is, what causes it, and how to adjust your diet accordingly to remedy this uncomfortable side effect.

What Is Constipation?

Many people assume that they need to have at least one bowel movement per day and any fewer means they’re constipated. In reality, what’s “normal” for one person may vary for another. Some people may have three bowel movements per day while some may have as few as 2-3 per week with no adverse consequences.¹

In short, constipation (also known as feeling “backed up”) is when your bowel movements become infrequent enough to cause symptoms such as:

• Bloating and abdominal pain/discomfort
• Straining to pass your stools
• Gut distention
• Frequent gas passing (or a hard time passing gas)
• Trouble breathing/feeling excessively full
• Hemorrhoids (in severe cases)

Even if you exhibit these symptoms, they may not be indicative that constipation is the main underlying issue. Many digestive problems have these same symptoms. You might need to do a little more investigative work if you suspect that constipation isn’t causing you discomfort.

A handy, albeit unpleasant way of checking whether you’re actually constipated, is to examine your stool “quality” and referring to the Bristol stool chart. Obviously, you don’t have to touch the stool or anything. Just look at it after you have a bowel movement and get a general idea of its shape, hardness, and anything that stands out.

If you’re not a fan of checking out your own poop, and you feel your symptoms are the result of constipation, there are a handful of dietary adjustments you should try.

Can Keto Cause Constipation?

Constipation isn’t something that only the keto diet can cause. In reality, any diet that is lacking in certain nutrients can cause constipation (among a variety of other health ramifications). As such, if your keto diet is well-balanced, then chances are it won’t make you constipated, nor should it give you diarrhea.

If you recently made the jump to the keto diet and you find your bowel movements becoming less frequent, then keto constipation may be the issue. Here are several reasons you may be experiencing keto constipation.

Lack of or Too Much Fiber

Hands down the most common mistake people make when they switch to the keto diet is overlooking their fiber intake. Since the keto diet is essentially grain-free, your fiber intake can drastically decrease if you don’t compensate accordingly.

So, what makes fiber so crucial for staying regular? Dietary fiber acts through several mechanisms to help promote gut motility and support healthy gut microbiome balance. Both of these directly influence bowel movement frequency.²

When you don’t consume enough fiber, your body will struggle to move stools efficiently. If left unmanaged, this can eventually manifest into irritable bowel syndrome (IBS).

Not surprisingly, research suggests that the majority of adults on a typical Western diet fall well short of their daily fiber needs.³

Intuitively, eating plenty of fiber is a prudent way to stay free of keto constipation.

However, when people become aware of this, their reaction is to eat tons of fiber; ironically, this is not going to be good for keto constipation either.⁴

The key is to find a happy middle-ground. For most adults, 25-35 grams of fiber per day is plenty to support healthy gut/bowel function, among other things. One study found that women who consumed roughly 20 grams of fiber per day were significantly less likely to experience constipation than those who fell short of that number.⁵

It’s important to note that not all fiber is made equal. The two types of fiber you find in food are soluble fibers and insoluble fibers. Soluble fibers readily bind with water to form gel-like substances in the gut that help add bulk to stools. Insoluble fibers, on the other hand, pass through the gut relatively unchanged and help promote the movement of material through the GI tract.

On the keto diet, the vast majority of your fiber will come from vegetables, which are great sources of both soluble and insoluble fibers.

Micronutrient Deficiency

Micronutrients are arguably the most overlooked aspect of any diet, whether it’s keto or not. In contrast to macronutrients, micronutrients are substances that our bodies only require in relatively small amounts. Examples of micronutrients are vitamins and minerals.

While you only need small amounts of micronutrients for health and longevity, that doesn’t mean they are not important. Quite the opposite actually, as research suggests that micronutrient deficiencies are a growing health concern among the general population.⁶

Some scientists and clinicians even go so far as to assert that low micronutrient intake is an underlying cause of morbidity and mortality.

So, how do micronutrients affect constipation? In reality, the more appropriate question is how don’t micronutrients affect constipation?

There are 100s of micronutrients that we need for healthy cellular physiology, impacting every bodily system. Major micronutrients that play a role in bowel frequency are electrolyte minerals (particularly magnesium). In fact, low magnesium intake is associated with ongoing constipation in otherwise healthy individuals.⁷

This is one reason why you’ll often find magnesium hydroxide (also known as milk of magnesia) in over-the-counter laxatives.

Ensuring you consume an adequate amount of vitamins and minerals daily is crucial not for just treating/avoiding keto constipation, but for overall health and longevity. The good news is that the keto diet encourages people to focus on eating nutrient-dense vegetables, meats, and fats, all of which can be great sources of vitamins and minerals.

If you need further guidance, check out: Best Low Carb Vegetables for the Keto Diet

Gut Microbiome Imbalance

The gut microbiome is more or less the “second brain” of the human body. Yes, your gut is quite like the command center to many physiological processes, and also home to trillions of microorganisms that directly influence how we think, feel, and function.⁸

Much like the brain, we are still far from understanding the intricacies of the human gut and the multitude of host-bacterial interactions that directly impact our health and well-being. However, research is rapidly growing with regards to the human gut microbiome. We are slowly getting a clearer grasp of what specific bacterial species are beneficial and which are not, particularly those that can treat constipation and IBS.

Hence, it’s imperative to starve the “bad” microbes while feeding the “friendly” ones. In general, feeding your body with prebiotic fiber is the best way to nourish healthy bacteria with the fermentative fuel that they need to replicate and flourish.⁹

Prebiotics are ostensibly the most effective way to balance the gut microbiome and alleviate constipation. While probiotics are useful in limited contexts, eating a diet with enough prebiotic fiber is the better long-term solution. Doing so stimulates the healthy microbes in your gut to grow and “outcompete” the unhealthy microbes.

A special type of prebiotic fiber is fructooligosaccharides (FOS), which are readily made from inulin – a dietary fiber component of chicory root. FOS appears to be one of the most beneficial prebiotic fibers, especially for bifidobacteria and lactobacilli.¹⁰

For further reading on prebiotic fiber on the keto diet, be sure to check out: Keto Diet Gut Health Benefits

Not Eating Enough

While most people start the keto diet to lose weight, this often results in a significant reduction in overall food intake. This makes it hard for the body to produce enough fecal matter for regular bowel movements.

It may seem like common sense, but depriving yourself of energy is a surefire way to get “backed up.” Even if you’re trying to lose weight on keto, don’t cut too many calories from your diet.

This is especially crucial if you’re coming from a diet that was very high in calories. For the majority of newcomers to the keto diet, a 20% reduction in overall calorie intake will be plenty to kickstart the weight loss process without significantly affecting bowel movement frequency.

Remember, since you’re cutting out grains on the keto diet, chances are your fiber intake is going to drop. Make it a point to eat a good amount of vegetables every day. When you pair low fiber intake with excessively low overall food intake, your bowel movement frequency and stool composition with inevitably change for the worse.

The Keto Flu

The keto flu is a phenomenon many people experience around the end of weeks 1-2 after cutting out carbs. The symptoms of keto flu are much like that of influenza, hence the term “keto flu.”

The most common symptoms of keto flu are brain-fog, lethargy, muscular aches, and short-term constipation. However, these symptoms are usually ephemeral and easy to treat with some dietary modifications, rest, and supplement use.

If you are experiencing the keto flu, we have a handy guide that walks you through how to treat it fast and effectively: How to Fix the Keto Flu

Other Potential Causes

Some other common causes of keto constipation are not drinking enough fluid and ingesting foods that you’re intolerant of or allergic to. Remember, soluble fibers bind with water to help soften stools and add bulk to them. If you don’t drink enough water, then you’re missing out on the potential benefits of fiber for helping relieve your constipation.

Moreover, consuming foods/drinks that your body doesn’t fully process (or that you’re allergic to) can exacerbate the symptoms of constipation. For example, lactose intolerance is well-known to cause gut distress, bloating, and trouble passing stools.

While your lactose consumption should be quite low on keto, be sure to rule out any common food intolerances or allergies. The good thing about a proper keto diet is that it’s essentially gluten-free and low in lactose by default.

How to Treat Keto Constipation: 8 Effective Remedies

If you’re new to keto and constipation has gotten the best of you, don’t fret! Here are some easy and effective workarounds that you can implement to remedy keto constipation and get back on track to regularity.

1. Eat adequate fiber

Eating a good amount of both soluble and insoluble fiber is your first line of attack against keto constipation. For most adults, you’ll want to consume between 25-35 grams of fiber per day for promoting healthy bowel movement frequency.

Try to eat a balance of soluble and insoluble fibers, as well as prebiotic fibers, like inulin. You can also use an inulin supplement if you prefer. It actually has a sweet taste naturally that would go well with Bulletproof Keto Coffee.

Soluble fibers can be hard to find in foods on the keto diet since it’s generally most abundant in grains and fruits. However, avocados, broccoli, and Brussels sprouts are all great sources of soluble fiber that are low in carbs.

Insoluble fibers should be easy to fit into your keto diet. They are the major nutrient in cauliflower, asparagus, spinach, kale, green beans, nuts, okra, and many other low-carb plant foods.

2. Stay hydrated and well-fed

In case you haven’t noticed, hydration has been a recurring theme throughout this article. Water is essential for helping soften and move your stools through the colon. Skimping on fluid intake is only going to increase the chances you experience keto constipation.

A good starting point for most people on keto is 100 ounces of water per day. If you are a larger individual or highly active, you might need closer to 150 or even 200 ounces of water daily to stay properly hydrated.

In conjunction with drinking plenty of water, you want to ensure you’re consuming adequate amounts of energy, even if you’re trying to lose weight. To reiterate from earlier, depriving yourself of food makes it next to impossible for your body to produce sufficient fecal matter.

Intuitively, you’ll want to avoid things like intermittent fasting and fat fasting if your main priority is relieving constipation. While IF and fat fasting can be useful tools in the short-term, they are not going to be ideal if you’re constipated.

3. Eliminate food allergens and intolerances

Gluten and lactose are two of the most common nutrients for people to either be allergic to or not tolerate well. As aforementioned, a proper keto diet will inherently be gluten-free and very low in lactose. If you have been eating more dairy on the keto diet and notice that you’re constipated, try cutting out the dairy and see if the symptoms subside.

If you’re allergic to nuts or other foods, be careful about what you eat on keto. While many nuts are great sources of healthy essential fatty acids, you should absolutely avoid them if you have an allergy.

4. Exercising

Exercise seems to be the solution to many health problems, and constipation is yet another one you can add to the list. In fact, research shows that inactivity is one of the most common causes of chronic constipation.¹¹

Many people hear the word “exercise” and assume it means going to a gym and hoisting heavy barbells. The reality is that virtually any type of movement that requires diligent effort is healthy and beneficial.

If you’re not the gym-goer type, the possibilities are still endless. Go out for a jog with your dog after work, start the day with a walk around the neighborhood, ride your bike to the grocery store, or go for a hike with a friend.

There’s no excuse to not exercise, and it should be a component of your health regimen regardless of your diet.

5. Consume exogenous ketones

Exogenous ketones tend to have a mild laxative effect since BHB salts are often present as magnesium-BHB. If you don’t want to experience a laxative effect from exogenous ketones, ingesting MCTs are said to help offset its influence on bowel movement frequency.

6. Supplement with probiotics

Taking a probiotic supplement is essentially like implanting friendly microbes into your gut. The trick with probiotics is finding the ones that contain the appropriate microbial strains for the health condition(s) you want to treat/improve.

In general, most probiotics on the market will help with constipation. However, a select few strains stand out based on the available research, particularly those in this lactobacilli and bifidobacteria genera.

One such strain is L. acidophilus NCFM®, which is a patented beneficial lactic acid bacteria strain. This is often used to treat lactose intolerance and constipation by promoting the digestion of simple sugars and otherwise tough-to-digest nutrients.¹²

Several studies have found that L. acidophilus NCFM® shortens colon transit time, thereby alleviating constipation.¹³,¹⁴

Research suggests that L. acidophilus NCFM® may also activate endocannabinoid and μ-opioid receptors in epithelial cells in the colon. This can lead to an analgesic effect and easing colonic pain commonly associated with constipation.¹⁵

For further probiotic guidance, check out: The Top 7 Probiotics for Keto

7. Supplement with electrolytes

As mentioned earlier, electrolytes – especially magnesium – are key for optimal regularity. The keto diet tends to make it tougher for the body to retain electrolytes. During the keto diet, you might urinate more frequently, and you’ll be holding less glucose to attract water molecules. If you find that you’re constipated on keto, try supplementing with an electrolyte blend containing magnesium, calcium, sodium, and potassium (phosphorus is good too).

Thankfully, you can find a good amount of these electrolytes in most exogenous ketone supplements since BHB is typically present in salt form.

8. Try using activated charcoal

Activated charcoal is a natural substance found in coconut shells and other organic sources. It is commonly used for bloating, indigestion, constipation, and eliminating toxins from the body. Be sure not to confuse activated charcoal with typical barbecue grill charcoal, as the latter is something you should never consume directly.

Activated charcoal contains millions of pores with a negative electric charge on its surface, which enables it to effectively trap positively charged chemicals and toxins.

Activated charcoal works through a process known as adsorption (not to be confused with absorption). When activated charcoal is consumed, toxins and other chemicals bind with its surface and are “flushed out” of the body. For this reason, it’s crucial to consume adequate water when using activated charcoal to avoid dehydration.

Furthermore, research demonstrates that ingesting activated charcoal before typical gas-producing meals effectively alleviate bloating and flatulence.¹⁶,¹⁷ There also appears to be anti-aging benefits of activated charcoal due to its detoxifying actions, as well as promoting healthy blood lipid levels and supporting healthy kidney and liver function.¹⁸,¹⁹

When to Use OTC Laxatives for Keto Constipation

Aside from an enema, over-the-counter laxatives should be your last resort for relieving keto constipation. If you’ve tried all of the above tips for keto constipation and find that your still backed up, then there are a select few OTC laxatives that might do the trick.

One of the most well-researched soluble fibers supplements for supporting healthy stool is psyllium hydrocolloid. This fiber is found in the seed husk of Plantago ovata and is composed of highly branched, fermentation-resistant arabinoxylans.   

Psyllium fiber works by shortening bowel transit time through gentle peristalsis of the intestines. Studies consistently show that psyllium supplementation produces a bowel movement within 6-12 hours of consumption.²⁰

Additionally, psyllium husk appears to be beneficial for supporting healthy blood lipid and blood glucose balance.²¹

Other natural OTC laxative options include senna leaf and buckthorn bark, which are natural sources of anthraquinone glycosides that break down in the body to directly promote colonic motility and fluid secretion within the large intestine.²²,²³ Senna and buckthorn are considered to be gentle stimulant laxatives when compared to other common options, such as castor oil and bisacodyl.

If all else fails and your constipation persists, contact your doctor immediately or go to a nearby urgent care/hospital as there may be a more serious underlying gastrointestinal issue.

Keto Constipation: Key Takeaways

• Constipation is not an uncommon issue for those on the keto diet, particularly if you’re new to the carbless lifestyle.
• The main cause of constipation on keto is either eating too much or too little fiber. For most adults, 25-35 grams of fiber per day is adequate.
• Drinking plenty of water (at least 100 ounces per day) and eliminating potential food allergens and food intolerances are key to avoiding constipation and digestive issues.
• Probiotics can be useful for constipation in certain circumstances, but prebiotic fiber is a long-term solution to balancing the gut microbiome and promoting regularity.
• Exogenous ketones and electrolyte supplements tend to have mild laxative properties that can help relieve short-term keto constipation.
• Exercising is one of the most integral parts of a well-rounded health regimen, and staying active is a great way to keep your bowel movements in order.
• OTC laxatives should be a last resort if more conservative measures don’t relieve your constipation. Always be sure to contact your doctor if you experience constipation lasting longer than seven days as it’s doubtful to resolve without further intervention.

References

1. Maruyama, M., Kamimura, K., Sugita, M., Nakajima, N., Takahashi, Y., Isokawa, O., & Terai, S. (2019). The Management of Constipation: Current Status and Future Prospects. In Constipation. IntechOpen.
2. Koh, A., De Vadder, F., Kovatcheva-Datchary, P., & Bäckhed, F. (2016). From dietary fiber to host physiology: short-chain fatty acids as key bacterial metabolites. Cell, 165(6), 1332-1345.
3. Cordain, L., Eaton, S. B., Sebastian, A., Mann, N., Lindeberg, S., Watkins, B. A., … & Brand-Miller, J. (2005). Origins and evolution of the Western diet: health implications for the 21st century. The American journal of clinical nutrition, 81(2), 341-354.
4. Ho, K. S., Tan, C. Y. M., Daud, M. A. M., & Seow-Choen, F. (2012). Stopping or reducing dietary fiber intake reduces constipation and its associated symptoms. World Journal of Gastroenterology: WJG, 18(33), 4593.
5. Dukas, L., Willett, W. C., & Giovannucci, E. L. (2003). Association between physical activity, fiber intake, and other lifestyle variables and constipation in a study of women. The American journal of gastroenterology, 98(8), 1790-1796.
6. Black, R. (2003). Micronutrient deficiency: an underlying cause of morbidity and mortality.
7. Murakami, K., Sasaki, S., Okubo, H., Takahashi, Y., Hosoi, Y., & Itabashi, M. (2007). Association between dietary fiber, water, and magnesium intake and functional constipation among young Japanese women. European journal of clinical nutrition, 61(5), 616.
8. Shreiner, A. B., Kao, J. Y., & Young, V. B. (2015). The gut microbiome in health and in disease. Current opinion in gastroenterology, 31(1), 69.
9. Gibson, G. R., & Roberfroid, M. B. (1995). Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. The Journal of nutrition, 125(6), 1401-1412.
10. Huebner, J., Wehling, R. L., & Hutkins, R. W. (2007). Functional activity of commercial prebiotics. International Dairy Journal, 17(7), 770-775.
11. Jamshed, N., Lee, Z. E., & Olden, K. W. (2011). Diagnostic approach to chronic constipation in adults. American family physician, 84(3), 299.
12. Malcolm W. Hickey, Alan J. Hillier, G. Richard Jago (1986). Transport and Metabolism of Lactose, Glucose, and Galactose in Homofermentative Lactobacilli. Appl Environ Microbiol.; 51(4): 825–831.
13. Ringel-Kulka T., et al., (2014). ‘Lactobacillus acidophilus NCFM affects colonic mucosal opioid receptor expression in patients with functional abdominal pain – a randomized clinical study’. Aliment Pharmacological Therapy., 40(2):200-7.
14. Sanders M. E, and Klaenhammer, T. R., (2001). ‘Invited Review: The Scientific Basis of Lactobacillus acidophilus NCFM Functionality as a Probiotic’. Journal of Dairy Science Vol. 84(2):319-331.
15. Rousseaux C. et al., (2007), ‘Lactobacillus acidophilus modulates intestinal pain and induces opioid and cannabinoid receptors’. Nature Medicine, 13(1):35-7.
16. Lecuyer, M., Cousin, T., Monnot, M. N., & Coffin, B. (2009). Efficacy of an activated charcoal–simethicone combination in dyspeptic syndrome: Results of a placebo-controlled prospective study in general practice. Gastroenterologie clinique et biologique, 33(6), 478-484.
17. Coffin, B., Bortolloti, C., Bourgeois, O., & Denicourt, L. (2011). Efficacy of a simethicone, activated charcoal and magnesium oxide combination (Carbosymag®) in functional dyspepsia: results of a general practice-based randomized trial. Clinics and research in hepatology and gastroenterology, 35(6), 494-499.
18. Ostlund, R. E., Racette, S. B., & Stenson, W. F. (2003). Inhibition of cholesterol absorption by phytosterol-replete wheat germ compared with phytosterol-depleted wheat germ. The American journal of clinical nutrition, 77(6), 1385-1389.
19. Vaziri, N. D., Yuan, J., Khazaeli, M., Masuda, Y., Ichii, H., & Liu, S. (2013). Oral activated charcoal adsorbent (AST-120) ameliorates chronic kidney disease-induced intestinal epithelial barrier disruption. American journal of nephrology, 37(6), 518-525.
20. Ashraf, W., Park, F., Lof, J., & Quigley, E. M. M. (1995). Effects of psyllium therapy on stool characteristics, colon transit and anorectal function in chronic idiopathic constipation. Alimentary pharmacology & therapeutics, 9(6), 639-647.
21. Anderson, J. W., Allgood, L. D., Turner, J., Oeltgen, P. R., & Daggy, B. P. (1999). Effects of psyllium on glucose and serum lipid responses in men with type 2 diabetes and hypercholesterolemia–. The American journal of clinical nutrition, 70(4), 466-473.
22. Jun, H. U., Tang, J., Yang, J., Hailin, B. I., Xiao, Y., Pan, Y., & Lin, S. U. (2017). Research progress on the Pharmacology of senna. International Journal of Traditional Chinese Medicine, 39(2), 189-192.
23. Korulkin, D. Y., Muzychkina, R. A., & Kojaev, E. N. (2015). Physiological Action of Anthraquinone-Containing Preparations. World Academy of Science, Engineering and Technology, International Journal of Medical, Health, Biomedical, Bioengineering and Pharmaceutical Engineering, 8(7), 458-462..