Can Intermittent Fasting Cause Constipation?

Written by Andrew Brewer. ⚕️Reviewed and fact checked by our medical team.

can intermittent fasting cause constipation

There are many benefits to intermittent fasting. You’ll lose weight, improve your blood sugar, lower cholesterol, and more. Still, your body is adjusting to a new way of operating, and with that can come a steep learning curve. You may suffer from constipation if you don’t drink enough water or eat enough fiber during your mealtimes. This can become uncomfortable, so here’s everything you need to know if you come down with constipation while intermittent fasting.

Key Takeaways

  • Intermittent fasting itself does not cause constipation. It’s what you eat and drink during your non-fasting periods that can impact your bowel movements.
  • Constipation can be a side effect of a poor diet lacking fiber and water. Incorporating fiber-rich foods like vegetables and fruits, as well as drinking plenty of water, can help prevent constipation.
  • Drinking too much caffeine, including coffee and tea, can also contribute to constipation. It’s important to balance caffeine intake with water consumption to prevent dehydration and maintain healthy bowel movements.
  • Regular exercise can help prevent constipation by stimulating your bowels and decreasing the amount of time stool sits in your digestive tract.
  • If constipation persists or becomes severe, it’s important to consult a doctor to rule out any underlying medical conditions or to receive appropriate treatment.

Why Am I Constipated?

You’d think that while your body is fasting, it will want to purge everything left in your intestines as it burns through the remaining calories. However, that’s not always the case. When you change what you eat, your bowel movements can change in response. Consider what you’re eating during your windows.

If you’re constipated, you may need to integrate more fiber into your diet. Vegetables like spinach, peas, and broccoli and fruits like strawberries, bananas, oranges, and apples contain a healthy amount of fiber. They are healthy foods that are gentle enough to break your fast while pumping your body will the nutrients it needs to thrive.

If your drink too much caffeine, including coffee and tea, you may also notice an increase in constipation or diarrhea. Water will be your best bet when intermittent fasting, so make sure to drink a lot of it. Otherwise, you may become dehydrated, and your bowel movements may suffer.

Even if you’re eating a lot of fiber, you may still be constipated because you’re not drinking enough water, so it’s important to take note of your intake and adjust accordingly. Fasting apps can help you keep track of what you’re putting into your body, getting the best results during intermittent fasting.

How Can I Prevent Constipation?

While it may be tempting to eat what you want when you’re not fasting, resist the urge. This can be a shock to your system, causing constipation or diarrhea. Eating fiber-rich foods and drinking water are a great start to preventing constipation while drinking coffee can help force a bowel movement.

Be sure not to drink too much caffeine or use too much artificial sweetener, or you may start to have the opposite problem. Black coffee is best and can help you pass your stool comfortably. Remember to balance your caffeine intake with water to prevent dehydration. While coffee is made with water, it’s no substitute for the real thing!

If you’re uncomfortable, the last thing you want to do is to get up and move, but that will help get your bowels moving. It will decrease the amount of time the stool is just sitting in your digestive tract. Because of that, your body will absorb less water from the waste, making it easier to pass. Your stool will be softer, and you won’t have to strain to pass it.

Walking, running, swimming, riding bikes, and other cardio activities can help you feel better if you’re constipated and prevent it from happening in the future.

So, Can Intermittent Fasting Cause Constipation?

It’s not intermittent fasting that causes constipation. It’s what you put in your body when you’re not fasting that does. A lack of fiber and water can cause your bowels to back up, causing constipation. This will be compounded if you are not active, so it’s important to pay attention to what you eat and drink in addition to how active you are.

In a pinch, a cup of black coffee can help stimulate your bowel movements without breaking your fast, as long as you don’t add sugar and milk. Intermittent fasting doesn’t cause constipation, but it can be a side effect of a poor diet.


  • Can intermittent fasting cause constipation?

Yes, intermittent fasting can cause constipation in some individuals, especially if they do not consume enough fiber-rich foods during their eating periods.

  • How does intermittent fasting cause constipation?

Intermittent fasting can cause constipation by reducing the frequency and amount of food intake, which can slow down the digestive system and reduce bowel movements. Additionally, reducing food intake may lead to decreased consumption of fiber-rich foods, which can further contribute to constipation.

  • What are the symptoms of constipation?

Symptoms of constipation can include infrequent bowel movements, difficulty passing stools, hard or lumpy stools, abdominal discomfort, bloating, and a feeling of incomplete evacuation.

  • How can I prevent constipation while doing intermittent fasting?

To prevent constipation while intermittent fasting, consuming enough fiber-rich foods during your eating periods is important. Good sources of fiber include fruits, vegetables, whole grains, legumes, nuts, and seeds. In addition, drinking plenty of water and staying hydrated can also help.

  • What are some other potential side effects of intermittent fasting?

Other potential side effects of intermittent fasting include headaches, dizziness, fatigue, irritability, and difficulty concentrating. Speaking with a healthcare provider before starting any new diet or fasting regimen is important.

Andrew Brewer

Andrew Brewer

Andrew Brewer started to give people the guidance that he never received when he was first starting. His goal is to make your goals achievable and to offer you only the best fasting apps that the internet has to offer. You're not on your own - Andrew and the entire family of reviewers at are here with you every step of the way!