Keto Diet Constipation: What Causes and How to Fix

keto constipation


J. K. Rowling

Constipation is a state when you experience trouble having regular bowel movements. They might be infrequent or arduous to pass, and that is definitely not gripping. However, if constipation happens, it draws your attention entirely.

How do you know you are constipated? Usually, it is considered an issue to have a stool less than three times a week or if you don’t have any bowel movements for more than three days.

However, you might still be constipated even if you have a regular daily stool. If it is painful or takes too much effort to move your bowels or you have a feeling that something is “left undone”, that might also be a sign of a bowel blockage issue.

What Is Causing Constipation?

Instead of being considered a disease by itself, constipation is usually viewed as a symptom of various health problems. They might include eating disorders, stress, not being active, overeating dairy, lack of probiotics and others.

Keto constipation is slightly different. If hard bowel movements haven’t been an issue before changing your diet, and now they are, a reason might be the transition to a keto lifestyle.

Here are several reasons why keto constipation could happen.

Lack of Fiber


Fiber is a type of carbohydrate that is contained in plant-derived sorts of food and can’t be broken down into sugar molecules. You might have heard about how it benefits your health. “Eat more fiber to keep constipation away” — probably the most common words of advice you might hear if you want to treat blocked bowel issue on a ketogenic diet.

How much is enough? The last edition of Dietary Guidelines for Americans suggests the recommended intake for daily fiber is 14 grams per every 1000 kcal eaten. That means if you follow a 2000 kcal diet, you should consume 28 grams of fiber each day to benefit your health.

That may sound straightforward — just fill up with fiber and constipation won’t appear. But while it might be right for one person, it might be wrong for another one. Because fiber is not as simple as it might appear to be.

If you dive into science, you might discover two different types of fiber — soluble and insoluble.

Soluble Fiber

Soluble fiber holds additional water inside your digestive tract. As it goes through intestines, it becomes more gel-like and thus makes your stool softer and more comfortable to pass through the guts. As an additional benefit, it also might lower blood glucose level and slightly improve your cholesterol numbers.


Soluble fiber is present in many vegetables, fruits, legumes, and grains. The most soluble fiber-dense options are starchy foods, such as potatoes, beans, and grains. What they have in common is that they might not be your best friends while doing keto. Although there are some keto-friendly options that are quite good:

  • Avocados. One average fruit provides 4.2g.
  • Brussels sprouts. A cup of cooked brussels sprouts contains 4g.
  • Broccoli. One cooked cup contains roughly 2.4–3g.
  • Collard greens. One cooked cup is a source of 2.6g.
  • Hazelnuts. One-fourth of a cup of these nuts without shell contains 1.1g.

These values are provided by the Dietitians of Canada and are given for soluble fiber exactly.

Insoluble Fiber

Insoluble fiber doesn’t retain water and is solid. In contrast to soluble fiber, it adds firm mass to the stool in order to push everything through your digestive system. By the way, it is almost nondigestible and provides zero calories. Eating foods high in insoluble fiber is an excellent way to increase the amount consumed with just a little increment in calorie intake.


Even though this type of fiber doesn’t have any considerable water-holding capacity, it may contribute to softening your stool. As insoluble fiber moves through the large bowel, its large or coarse particles mechanically irritate the bowel’s mucosa, contributing to mucous and water secretion as a defense mechanism. (1)

The most common sources of insoluble fiber are wheat bran, beans, whole grains, nuts, and vegetables. Good keto-friendly sources include:

  • Avocados. While containing a lot of soluble fiber, it’s also a great source of the insoluble type.
  • Celery. If you are used to removing celery strings, you might consider breaking the habit as they are a great source of insoluble fiber.
  • Cabbage and broccoli. Especially the tough parts.
  • Asparagus. A cup of raw asparagus contains 2.8 grams of insoluble fiber.
  • Almonds. One cup of sliced nuts contains nearly 11 grams of insoluble fiber.

By the way, besides whole almonds, almond flour is also a significant source of fiber. It might be an excellent substitute for wheat flour when baking keto-friendly foods. If you are doing keto, fond of desserts and not afraid of baking, you might try an awesome Keto Lava Cake recipe. It takes only 20 minutes to bake and has only 2.9 net carbs per serving!

How Eating Fiber Affects Constipation

There might be several possible links between eating dietary fiber and having a hard stool issue. Here they are:

Not eating enough soluble fiber. Its water holding ability is important for stool softening and if the fiber is absent your stool consistency might become too firm and thus struggle to go through your digestive system.

Not drinking enough water. When your body is dehydrated, soluble fiber might be unable to attract enough liquid into your gut. Without it, your stool isn’t softened, and that might be a reason for constipation.

Not eating enough insoluble fiber. The bulk mass in your guts needs to be pushed all the way through your bowels, and the insoluble fiber you consume provides significant help to that passage.

Overeating insoluble fiber. If you are a huge fan of asparagus, celery or other sources of insoluble fiber listed above, eating enormous daily amounts might also constipate your digestive tract.

Knowing this might allow you to make a better choice on what sources of fiber to consume and how to leverage its benefits to avoid keto constipation.

Overwhelming Gut Microbes


Microbes like bacteria and archaea are indispensable parts of your gut system. You are able to digest food because you have them inside your digestive system.

However, you have only a certain quantity of different microbes, which evolved and grew up to be able to digest the particular type and amount of food you get with your daily eating routine.

People are different, that’s a fact. They are used to various eating patterns and subsequently develop different gut microbial compositions and hence digestive variability. What might be easily digested by one person, might cause another to bloat and become constipated.

If you started doing keto and experienced a bowel blockage issue, that might be because your healthy gut microbes were overwhelmed by a sudden shift in your eating routine. These adjustments recommended by Dr. Eric Berg might help you:

  • Alter the type of cruciferous vegetables you consume. This group includes cabbage, kale, brussels sprouts, broccoli, cauliflower, collards and so on. Some people might have an issue with its specific type and switching to another one may solve the problem.
  • If you avoided eating vegetables before doing keto and then dove into eating tons of leafy greens, take a step back and eat more lettuce and spinach. They are not so overwhelming to your digestive microbes and might be a better choice in the very beginning.
  • Fermented vegetables are easier to break down. Pickles, kimchi, and sauerkraut might be great options to switch over to.

Eventually, when the number of your healthy gut bacteria grows, you might be able to add more different types of vegetables without being constipated.


Losing water is inevitable when starting a keto lifestyle. The science behind it is that you get rid of your internal carb storage which holds up to 4 grams of liquid per each gram of carbohydrates. (2)

How exactly does dehydration affect your digestion?

drinking water

During ketosis, you get most of your calories out of fats. In order to break them down and move them forward, your liver produces bile, which is partly composed of water. When your liver doesn’t have enough liquid, the bile consistency might become more viscous and won’t lubricate your digestive tract well enough.

When your digestive tract isn’t smooth enough, it makes it harder for a bulk mass to be pushed all the way through to the colon, contributing to bowel blockage.

That is probably enough to consider dehydration as a factor affecting constipation, but there’s more to it. During the last stage of digestion which happens in the colon, some electrolytes, nutrients, and water are still being absorbed. When your body is dehydrated, it tries to get as much of those substances as it possibly can, drying your stool out even more and obstructing your bowel movement.

The proper solution for this is to merely drink more water.

Lack of Sodium

plain salt

If your body’s sodium concentration is low, that may result in a bowel movement issue. This may look weird at the first glance, but it does make sense.

When you don’t get enough salt with your regular meals, it might eventually result in a lower sodium concentration in your blood. But your body always tries to keep your internal parameters steady and thereby it might respond by lowering blood volume through renal water excretion. (3)

But as you know from the previous section, your colon is a water recovery organ. If you don’t have enough blood volume in your circulatory system, it will cause your colon to retain accessible fluid.

That might dry your stool out and be a reason for constipation. The remedy is simple — add more salt to your meals.

How Long Does Keto Constipation Last?

Given the nature of keto constipation, which is a result of transitioning to a low-carb diet, it might go away as soon as your body is adjusted to a new way of eating.  

However, everyone is different, and while it takes one person just a few days to adapt, it might take up to several weeks for another person to get used to new conditions. It correlates with your overall health and previous eating routine.

The good news is that if you haven’t suffered from being constipated before doing keto, you will probably be able to avoid or overcome that issue quite quickly.

How to Treat Keto Constipation

Summing up and adding few more minor tips, these measures might be taken to avoid or relieve the keto bowel movement issue:

  1. Drink enough water. Water balance is essential for your body to function correctly.
  2. Eat sufficient minerals. Sodium is crucial to keep hydrated, and lack of potassium may cause colon cramping and thus evoke constipation.
  3. Eat enough fiber. Never ignore vegetables, but don’t take ravenous bites of crucifers every thirty minutes. Stay within a recommended daily value.
  4. Don’t overwhelm your gut. Healthy bacteria, living inside of your digestive tract, need to grow their number and adapt to a larger amount of certain foods.
  5. Alter the nuts you eat. Sometimes eating too many wrong nuts may decrease enzyme activity and contribute to constipation. Cut them out for a few days or germinate them.
  6. Beware of dairy. Some people have lactose intolerance, which worsens dairy protein digestion and may promote backing up.
  7. Approach gradually. Minor changes require less adaptation than major ones and allow you to progress without being overstressed.
  8. Avoid stress. A variety of problems might be caused or worsened by stress, including constipation. Easier said than done, taking care of stress might be a great solution to them.


Keto constipation is real, and it may affect your life in a certain way. Those suggestions listed above will possibly help you solve the hard bowel movement issue and improve the frequency of your stool.

Nevertheless, all people differ. One man’s meal is another man’s poison; thus those tips might not be suitable for each and every individual. The good example of this difference might be these two studies on fiber and constipation. While the first one claims that eating fiber improves stool frequency, the second one says that constipation and its symptoms can be effectively reduced by stopping dietary fiber intake.

If you’ve been experiencing constipation for an extended period of time and want to get the specified piece of advice on how you individually could treat it, the best you can do is to contact your physician.

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