Does the Keto Diet Cause Constipation?

Author Image

Written by Edibel Quintero, Medical Doctor and medically reviewed by Abby Courtenay

Imge of Does the Keto Diet Cause Constipation?



Sometimes we believe that a diet will solve all our health problems, but it can also bring unforeseen side effects. In the case of the keto diet, it might surprise you that constipation is a common complaint.

There are many theories behind why this can occur. Although it is true that it depends on many personal factors, there are some general recommendations that you can follow to help solve or prevent it.

If you want to lose weight without worrying about keto making you constipated, read on for solutions to make your trips to the bathroom go smoothly.

Keto and constipation

Suffering from constipation on the keto diet is a serious topic. But because not everyone talks about it, perhaps you don't even imagine that it can be related.

To understand why you get constipated on keto, it is a good idea to do some research on what happens to digestion during ketosis.

First, constipation is defined as infrequent bowel transit or a decrease in the amount of stool.1 This condition causes great discomfort that can impair your daily activity.

In addition, the effort made to evacuate can bring serious complications such as anal fissures, rectal prolapse, and hemorrhoids.

What happens during digestion on the keto diet is that not enough soluble fiber is consumed (which is abundant in whole grain, legumes, fruits, and vegetables). Soluble fiber softens the stool because it retains water.2 Most of the fiber intake comes from insoluble fiber found in vegetables, nuts, and seeds, which only adds bulk to the stool because it is a waste product and does not retain water.

Is constipation a sign of ketosis?

When you start a ketogenic diet, there are certain signs that let you know you are getting into ketosis. By definition, ketosis is a metabolic state that forces the body to use fats for fuel instead of carbohydrates.3

The abrupt change in diet can affect your gut and hydration, so you may suffer from constipation for the first few weeks. However, this is not a direct sign that your body is starting to use fats for energy.

The best way to make sure you have entered ketosis is to identify other symptoms, such as keto breath4 or flu-like symptoms known as the "keto flu." You can also measure the amount of ketone bodies5 in your urine.


What causes keto constipation?

There are 3 basic points to keep in mind when you are following a keto diet to ensure that constipation is not a problem for you: 

  1. Minerals intake
  2. The amount of fiber you eat 
  3. Hydration

Let’s examine these in more depth.

Micronutrients also matter. When you start cutting carbs, a large amount of water is lost because carbohydrates retain water. This is why you lose weight so fast at the beginning of the ketogenic diet. Maintaining an adequate salt intake favors water retention and prevents dehydration, as well as other symptoms such as fatigue and headache.

Soluble and insoluble fiber. It is necessary to consume both types of fiber to achieve the ideal stool consistency. Insoluble fiber (vegetables, fruit skins, nuts, and seeds) provides bulk and soluble fiber (starchy vegetables, whole grains, and legumes) provides softness so that it can circulate. Although foods with fiber in the keto diet are reduced, it is enough to select the right carbohydrates to eat according to the allowed percentage to comply with the basic keto rules.

Water as a vehicle. You may be eating enough fiber, but if you don't drink water you will only cause all that waste to stagnate. Water acts as a lubricant of the digestive tract and is what allows stool to move easily throughout the intestine.


Does keto constipation go away?

If constipation is not a chronic problem for you, it definitely does go away after a few weeks, especially if you are following all the recommendations.

In addition to the points already mentioned, what helps constipation on a keto diet is to add a moderate exercise routine to promote intestinal transit, which will make you feel lighter.
If this side effect stays longer than it should or is a problem you had before going keto, the best thing to do is to contact your doctor to investigate what may be causing this issue.


How do you deal with constipation on the keto diet?

The following recommendations give you a step-by-step guide on how to relieve constipation on keto:

  1. Drink between 8 - 10 glasses of water a day. Add a couple more glasses if you do intense exercise.
  2. Make sure your meals contain green vegetables such as asparagus, spinach, and arugula.
  3. Add avocado to your meals, besides being an excellent source of fat, it contains soluble and insoluble fiber.
  4. Consume 4 - 5 grams of salt per day to allow all your vital functions to be fulfilled and avoid annoying symptoms typical of the keto diet. Remember that in addition to the salt you add to your food, some foods are high in salt (like bacon), which will also count towards this recommendation. 
  5. Move around. Let the gravity effect do its job and help you move the stool through the intestines.
  6. Clockwise abdominal massages in a circular motion from the right side to the left side are always a good ally to speed up the trip to the bathroom.


How to not get constipated on keto

  • From the beginning of the diet, be attentive to everything your body tells you. Although constipation is a common side effect, you don't have to be affected if you are prepared to prevent it. Starting the diet gradually and not abruptly will help avoid constipation on keto.
  • Keep your stress level low by being physically active and enjoying your favorite activities. The brain-gut connection6, which is increasingly studied these days, also plays a key role.
  • Follow the general recommendations on consuming enough water, fiber, and salt, and do not leave the visit to the doctor for the last minute if you see that things are not going well. Digestive health is important for the detoxification of your body, and that is a key point for weight loss.


Best laxatives for the ketogenic diet

A laxative should not be your first port of call and you should always discuss using one with your doctor as laxative abuse can be very dangerous. 

Some supplement options such as Magnesium Citrate7 are among the first to consider when constipation occurs.

While you can find a lot of fiber supplements on the market, many of them may be high in carbohydrates, so read the nutritional labels first.

One of the products that has gained popularity in recent years is mct oil for constipation, which is mainly used to accelerate ketosis.

Chia seeds and flaxseeds are the best natural keto-friendly laxatives because they contain a large amount of fiber and fatty acids in a small amount of product. You can add a spoonful to your salads and vegetable smoothies.

Let your doctor be the one to prescribe laxative medications to avoid complications.


Keto-friendly foods that help you poop

If you are experiencing constipation, what carbohydrate can you increase?

At the beginning of the diet as you transition to low-carb, eliminate refined carbohydrates and replace them with whole grains and legumes. These foods should be progressively reduced until the appropriate percentages are reached to achieve ketosis.

Here are the best low-carb keto foods to help you poop:

  • Water
  • Avocado
  • Chia seeds
  • Flaxseed
  • Asparagus
  • Berries
  • Peanut butter

How often should you poop on a ketogenic diet?

Stool frequency varies. Some people go twice a day, while others go once every 2 days. Both are fine, what is more important is noticing if there is a change in your usual patterns. If you usually poop 2 times daily but are now pooping once every 2 days, that is a change that you should take note of. 

There are many factors that affect these patterns, such as holding in the urge8 due to your type of work, the amount of junk food you eat, hydration, physical activity, and stress, among others.

Rather than how often you go, consistency is a better indicator for gut health. Stools should be soft and easy to pass. 


Other keto side effects related to constipation

Side effects related to constipation may be present simultaneously from the first day1, some of them are:

  • Abdominal bloating
  • Pain during bowel movements
  • Rectal bleeding
  • Loss of appetite
  • Headache
  • Chills
  • Fatigue
  • Irritability


At what point should you be concerned about this side effect?

Constipation is defined as less than 3 bowel movements per week. A body loaded with waste begins to show symptoms that can make daily tasks difficult, such as abdominal pain, nausea, irritability and fatigue.

In addition, there are other alarming symptoms for which you should see a doctor immediately1:

  • Blood in the stool
  • Severe abdominal pain
  • Constipation alternating with diarrhea
  • Excessive weight loss that does not seem to be related to the diet
  • Change in the shape of the stool (very thin, dark stool)
  • None of the measures you apply work (fiber intake, exercise, massages, laxatives, etc.)


Final thoughts about constipation on keto

Constipation is an unexpected consequence during the keto diet, which is why the importance of the transition is emphasized. Any abrupt change in dietary pattern can lead to uncomfortable symptoms.

Eliminating processed products and replacing them with complex carbohydrates is a good way to start, which will give you a good amount of fiber to stimulate your gut and the good bacteria that live in it.

Water and physical exercise will always be the gold standard in any process that pursues health, especially if you want to lose weight.

If you feel that you have followed all the recommendations and you are still suffering from constipation, do not hesitate to seek medical advice.



1. Patient Care & Health Information Diseases & Conditions: Constipation overview. Mayo Clinic. 

2. Dietary fibre in foods: a review. Journal of Food Science and Technology. 2012 Jun; 49(3): 255–266. Published online 2011 Apr 12. doi: 10.1007/s13197-011-0365-5 

3. Ketogenic diet in endocrine disorders: Current perspectives. J Postgrad Med. 2017 Oct-Dec; 63(4): 242–251. doi: 10.4103/jpgm.JPGM_16_17 

4. Guiding Ketogenic Diet with Breath Acetone Sensors. Sensors (Basel). 2018 Nov; 18(11): 3655. Published online 2018 Oct 28. doi: 10.3390/s18113655 

5. Ketone Bodies. Clinical Biochemistry of Domestic Animals (Sixth Edition), 2008. 

6. The gut-brain axis: interactions between enteric microbiota, central and enteric nervous systems. Annals of Gastroenterology. 2015 Apr-Jun; 28(2): 203–209. 

7. A Randomized Trial Comparing the Bowel Cleansing Efficacy of Sodium Picosulfate/Magnesium Citrate and Polyethylene Glycol/Bisacodyl (The Bowklean Study). Sci Rep. 2020; 10: 5604. Published online 2020 Mar 27. doi: 10.1038/s41598-020-62120-w  

8. Concerned About Constipation? NIH National Institute on Aging. December 01, 2013.