About fasting and irritable bowel

13. February 2023
Ida Marie Holm
Ida Marie Holm
Clinical nutritionist

Most people living with IBS have probably experienced that the food we eat affects IBS symptoms. But what about when and how often we eat? Fasting and eating fewer meals has been a popular topic in the past year. Many people believe that this can improve stomach and intestinal problems, but there is currently very little research to support this.

Many people have a good effect from eating more often

In terms of experience, we have seen that many people with IBS have a meal pattern where a long time can pass between meals, and many skip breakfast. These tend to get better by making adjustments to the length of time between each meal. Many have actually benefited greatly from introducing a breakfast meal, as opposed to a longer overnight fast!


Presumably, both those who reduce the number of meals and those who add meals have a few things in common. It is likely that both lead to meals becoming more regular (meaning that the various meals come at approximately the same time each day).

In addition, it is likely that both reduce snacking between meals and in the evening. In that case, this agrees well with what we know can be useful in IBS:

  • Regular meals (that is, eating the various meals at approximately the same time each day). A meal pattern that can suit many people is breakfast, lunch, dinner and snacks as needed.
  • Avoid skipping meals or leaving too much time between each meal. A stay of 3-5 hours between each meal will be a good starting point for most people.
  • Avoid eating late at night

Illustrasjonsbilde mellommåltid

Hopefully, we will get more studies on fasting and meal rhythm in IBS in the coming years. What they will show, it is too early to say anything about. For most IBS patients who are otherwise healthy, there is nothing to prevent them from testing whether fewer meals or longer night fasting can alleviate IBS symptoms. Feel free to use the IBS diary in the app to see if the changes have an effect.

NOTE: Not everyone should fast. This particularly applies to children and young people, pregnant and breastfeeding women, people who are underweight, malnourished or have a history of eating disorders. If you have conditions such as diabetes, or are taking medication for, among other things, blood pressure or heart disease, you should also exercise caution. We always recommend discussing dietary changes with your GP or other healthcare professional.


[1]: National Institute for Health and Clinical Excellence. Irritable bowel syndrome in adults. Diagnosis and management of irritable bowel syndrome in primary care London: NICE, 2008.

[2]: Cozma-Petrut A, Loghin F, Miere D, Dumitraşcu DL. Diet in irritable bowel syndrome: what to recommend, not what to forbid to patients! World J Gastroenterol. (2017)

[3]: Clevers E, Nordqvist A, Törnblom H, Tack J, Masclee A, Keszthelyi D, Van Oudenhove L, Simrén M. Food-symptom diaries can generate personalized lifestyle advice for managing gastrointestinal symptoms: A pilot study Neurogastroenterol Motil. (2020)