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The Keto Diet and Constipation: Why It Happens and How Do I Stop It?


Changing your diet can affect your bowel movements. If you’re starting a ketogenic diet, one of its possible side effects is constipation, along with weight loss and the keto flu (*).

Here’s everything you should know about keto constipation — why it happens when you go low-carb, remedies, prevention tips, and when to seek professional help.

Why Does the Keto Diet Cause Constipation?

Constipation usually happens within the first few days of going keto and may last for weeks depending on how soon your body adjusts to this way of eating and your remedies for easing it. Here are some reasons why you might experience constipation.

1. Too Little Dietary Fiber

For someone following a high-carbohydrate diet, cutting back on carbs can reduce their fiber intake.

That’s because fiber is commonly found in carb sources such as whole grains, rice, pasta, potatoes, apples, and bananas (*).

Dietary fiber adds bulk to and softens your stool, making it easier to pass. A meta-analysis showed that fiber increases stool frequency, which makes it a common treatment for constipation (*).

That said, you might want to check which high-carb plant foods you’ve been cutting from your diet recently.

Also, keep in mind that a low-carb diet doesn’t have to lack in fiber. It’s important to make sure that you’re finding other sources of fiber that won’t raise your blood sugar levels.

2. Dehydration

You may find that you’re losing a lot of water initially on keto, which could lead to dehydration (*).

A low-carb diet depletes your glycogen stores and lowers your insulin levels (*).

Glycogen is the storage form of glucose, and each gram of glycogen is stored with at least 3 grams of water. Along with the rapid water weight loss that occurs when starting this new diet, you’ll experience frequent urination (*).

Proper hydration is essential to ensure that your body has enough water to maintain normal bowel function (*).

This is especially important in those more susceptible to water losses such as athletes and people with active lifestyles (as a result of sweating), and older adults (* , *).

3. Lack of Physical Activity

Research shows that maintaining physical activity — whether exercise or non-exercise physical activity (such as yard work, standing, walking) — can promote bowel movements (*).

However, some people have low energy levels when starting keto due to the drastic reduction of carbs. Keto flu symptoms like headache, nausea, and irritability could also make you feel more tired than normal.

Especially when combined with factors such as a low fiber intake and dehydration, a lack of movement can be a reason for not pooping on keto.

If constipation persists for several weeks, you might want to consider looking into other causes. In that case, you should see a doctor for further evaluation and medical advice.

How to Treat Keto Constipation

While waiting for your digestive system to adjust to your new diet (which eventually happens), try using these keto constipation relief strategies at home.

how to treat keto constipation

1. Add Keto-Friendly High-Fiber Foods to Your Meal Plan

Fiber is a type of carbohydrate that your body can’t break down during digestion. It’s beneficial not just for making you feel fuller on fewer calories, but also for gut health.

As a keto constipation remedy, dietary fiber adds bulk to your stool, softens it, and increases your bowel movements (*).

In addition to easing constipation, prebiotics (a type of fiber) serve as food for your good gut bacteria. Promoting helpful bacteria can boost your immune system while also supporting weight loss (*).

Examples of low-carb vegetables with prebiotics include asparagus, mushrooms, cabbage, snow peas, garlic, and onions. There are many keto recipes to try these options.

You can also saute your meat or leafy greens with garlic, onion, or both to get prebiotic fiber, aside from enhancing the flavor of your meals.

Tip: Stick to non-starchy vegetables when embarking on the keto diet. Plant-based options generally help with constipation, but starchy veggies can raise your blood sugar levels, putting you out of ketosis.

2. Consume Snacks Sweetened with Sugar Alcohols

Sugar alcohols, also called polyols, are commonly used to sweeten keto foods and beverages. You’ll also find them in a lot of keto-friendly products like protein bars, chocolates, and cookies.

Examples of polyols are sorbitol, mannitol, erythritol, and xylitol (*). While these are low in calories and are unlikely to cause blood glucose spikes (making them a great choice for weight loss and managing blood sugar) — they can cause diarrhea when consumed in large amounts (* , *).

Because of their laxative effect, sugar alcohols can be used as a remedy for constipation. In that case, you may benefit from eating keto desserts sweetened with sugar alcohol.

However, if you have FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) intolerance, it’s best to avoid sugar alcohols, except for erythritol. This is to avoid worsening digestive symptoms like abdominal pain, bloating, and flatulence (*).

3. Increase Your Water Intake

Drinking more water can relieve keto flu symptoms such as headache, nausea, fatigue, and constipation caused by dehydration (* , *, *).

A clinical trial done on 117 patients showed that increasing fluid intake to 1.5-2.0 liters per day in addition to consuming a high-fiber diet, increases stool frequency in those with chronic functional constipation (*).

If you’re uncertain about whether you should drink more water, check your urine color. It should be colorless to lemonade (or light straw) in color if you’re optimally hydrated. However, if it’s a darker yellow, then it’s a good idea to drink up (*).

4. Add More Fat to Your Diet

As a high-fat diet, you should be eating more fat on keto. Dietary fat will serve as your energy source, and healthy fats like monounsaturated fats and omega-3 fatty acids reduce your risk of disease (* , *).

However, you might not be eating enough fat, especially if you’re just starting the keto diet. Eating more fat can reduce constipation since fat triggers the release of bile to help with digestion, and bile is a natural laxative (*).

Choose healthy fats like coconut oil, butter, animal fat (lard, tallow, suet), fatty cuts of meat, olive oil, and avocado oil.

You may have also heard of medium-chain triglycerides (MCTs) which are commonly used as a fat source or supplement to minimize keto flu symptoms, increase ketosis, and promote weight loss (* , *). Consider blending MCT oil, butter, and brewed coffee to make Bulletproof coffee.

5. Hold Off on Intermittent Fasting for Now

Intermittent fasting (IF) involves cycling between eating and fasting. For instance, fasting for 16 hours and eating your meals within the remaining 8-hour window.

Fasting is done to achieve physical and mental benefits, including weight loss, improved memory, and heart health (*). Take a look at this guide to learn more about intermittent fasting for beginners.

While a popular practice in the keto diet community (as it enhances ketosis and results), a downside is that it could lead to constipation (*). Possible reasons include a lack of fiber intake during your eating window and not getting enough water throughout the day.

If you’re already doing IF and are constipated, you might want to put fasting on pause until your bowel movements resume.

6. Incorporate Exercise Into Your Day

Research suggests that reducing sedentary behavior can help relieve constipation (*). In other words, simply moving more allows food to pass through your digestive system smoothly.

There are lots of exercises you can do while on the keto diet, such as light cardio (biking, swimming, hiking), resistance training, and flexibility workouts (yoga or pilates).

One helpful tip would be to take a short walk after every meal. On top of improving digestion, walking after meals suppresses hyperglycemia to keep your blood sugar levels under control and promote weight loss (*).

How to Prevent Keto Constipation

Applying the strategies discussed previously, such as adding low-carb fiber sources, hydration, adding dietary fat, and exercising can prevent constipation from happening.

Another approach is to do the keto diet gradually. Some people drastically lower their carbohydrates to enter ketosis, but you can take the slow route. While this won’t result in immediate ketosis, it will give your digestive system more time to adapt to your new diet.

When to Seek Professional Help for Constipation on Keto

Constipation that persists can lead to abdominal pain, bloating, and complications like hemorrhoids, fecal impaction, and rectal prolapse, especially if it lasts for weeks (*). Make sure to see your doctor. A health professional may recommend a fiber supplement or a laxative that doesn’t contain carbohydrates.

Your doctor might also explore other causes of constipation not related to the keto diet, such as medications you’re currently taking (if any) or a health condition (*).

Keto Constipation FAQ

Here are quick answers to the most common questions on the keto diet and constipation:

Can the Keto Diet Cause Constipation?

Yes, transitioning to the keto diet can lead to constipation, especially if most of your fiber sources are high in carbohydrates, such as grains and starchy vegetables. Keto is a very low-carb eating approach. Therefore, you should be looking for alternative fiber sources that won’t kick you out of ketosis.

Keto constipation may also result from dehydration (due to glycogen depletion and not staying hydrated) and a lack of physical activity.

Is Constipation a Sign of Ketosis?

Constipation is one of the things that could happen while you’re in ketosis, as a result of your dietary change. However, constipation should not be your basis for checking ketosis. The best approach is to test for increased ketone levels in your urine, breath, or blood.

What Helps Constipation on Keto?

Simple home remedies like eating low-carb high-fiber foods, ensuring proper hydration, moving more, holding off intermittent fasting, increasing your fat intake, and consuming keto treats with sugar alcohols will relieve constipation. If you haven’t started keto yet, consider doing it gradually to allow your digestive system to adjust and avoid constipation.

Schedule an appointment with your healthcare provider if you’re still not able to poop and feeling unusual symptoms you’re not sure about.

How Often Should You Poop on the Keto Diet?

As a general rule, the normal bowel movement ranges from once per day to three times a week. This can vary from one person to another and is affected by factors such as your activity level, age, illness or a health condition, a change in your macros, and certain medications.

Is Keto Dangerous for Digestive Health?

There isn’t enough scientific evidence to show that the keto diet wreaks havoc on your gut. Furthermore, keeping a healthy gut while on keto entails eating a diverse range of foods that feed beneficial gut bacteria and avoiding offenders like sugar and FODMAPs (if you’re intolerant to FODMAPs) (*).


Constipation is a side effect of going keto for the first time, and this is your GI tract’s response to very few carbohydrates (which may have been your primary source of fiber). It can also happen if you don’t drink enough water and move less because hydration and movement get things moving in your digestive tract.

By transitioning slowly to the keto diet and trying simple remedies like consuming foods with fiber, moving more, replenishing water losses, and increasing fat — you can avoid constipation in the first place or relieve it.

Be sure to speak with your doctor or a health professional if constipation persists.

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