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Can a Keto Diet Help Your IBS? | A Dietitian Explains.

Feature, Gut Health & IBS | September 18, 2017

A young girl feeding her father a nutritious homemade sandwich.
Can a Keto Diet Help Your IBS? | A Dietitian Explains. Featured Image

As you may have heard recently, there has been a lot of buzz surrounding the ketogenic (keto) diet and its ability to manage irritable bowel syndrome (IBS) – but does it really work? Today I’m here to unravel the mystery of the keto diet and if it’s something you should be considering to manage your IBS.

What is a Keto Diet?

A ketogenic diet is low in carbs but sufficient in protein and high in fat. It’s commonly used as a diet to manage patients with epilepsy to reduce seizure frequency1 – BUT you’ve probably more seen it around the internet touted as the ‘if paleo didn’t work – you should try this’ kinda diet. (cough cough FAD cough cough).

If you’ve read our previous post about why you should break up with your diet, you may remember that low-carbohydrate diets send our bodies into ketosis. When the body doesn’t have enough glucose as fuel, it turns our fat stores into ketones for energy instead. Over time, it can cause impacts such as muscle loss, appetite suppression, and slowed metabolism2 – not to mention food fixation, and a general dislike for any person who liberally eats carbohydrates.

can a keto diet help your IBS (irritable bowel syndrome)? Andrea Hardy, registered dietitian and gut health expert talks about the science behind the ketogenic diet and IBS, and what you need to know before you start a keto diet. | Ignite Nutrition Inc. Calgary Alberta Registered Dietitian Nutritionists

How Does the Keto Diet Help Your IBS?

IBS is a functional gut disorder – which you can read all about in my previous posts here, and here. People with IBS often experience constipation, diarrhea or cycles of both. Although the exact cause of IBS is still unknown, research has suggested that family history of IBS, other digestive disorders, gut infections, dietary pattern, stress, and gut bacteria imbalance may be associated with IBS. IBS can be triggered by foods that differ between individuals.

High FODMAP (fermentable carbohydrate) foods are known, through evidence based research to cause symptoms. In those with IBS, when high FODMAP foods ingested in large amounts the result is bloating, gas, changes in bowel movements, and visceral hypersensitivity (aka you FEEL things in your gut a lot more).

Very little research has looked into the benefits of a keto diet for IBS. However, one study found that IBS patients who suffer mainly from diarrhea (IBS-D) experienced symptomatic improvement after going on a very low-carbohydrate diet (in other words, a keto diet). These patients experienced improved stool consistency, reduced abdominal pain and improved quality of life3. This, of course is exciting – however, there are some shortcomings of relying on ONE study with a very strict diet intervention to apply to EVERYONE with IBS.

The questions you SHOULD be asking are: 

  • Is that extreme of a diet needed to get similar symptom relief?
  • Did the study ACTUALLY measure what we think it measured: Was the removal of FODMAP’s (fermentable carbs) through that resulted in symptom control, and NOT the fact that it was a very low carbohydrate diet?
  • What is the diet missing when we cut out these carbs, and how does it affect gut health long term?


The problem I have with a low carbohydrate diet is this.

  • Sustainability – When you use a keto diet, you limit your carbs to around 20 to 100 grams a day. Therefore, if you are a pasta, bread or rice lover, you will have to sadly cut ties with them all. Vegetables such as spinach, kale, lettuce will become your best friends. So if you are someone who dislikes leafy greens. I’m ALL about them vegetables – however, when you dichotomize food like this – it tends to lead to a negative relationship with food! I talk A LOT about this on Instagram. If you engage in ‘last supper’ mentality (eating large quantities of carbs when you ‘cheat’ under the guise that you’ll NEVER do it again) , if you feel guilty when you eat carbohydrates, or if you find yourself obsessing over what you can’t eat and hating what you do, then this diet is NOT for you.
  • Variety – Variety is not only the spice of life – but your microbiome REQUIRES variety! There’s only 1 you, but there’s over 1000 species of bacteria in your gut – all requiring a variety of different fuels. Our carbohydrate containing foods contain ‘prebiotics’ which act as fuel for your bacteria. Without them, what will your gut bacteria eat? Chances are, you’ll lose important species in your gut, and have a drop in both abundance and diversity of bacteria – both of which are associated with a less healthy microbiome.
  • Adequate fibre – When you use a keto diet to manage your IBS, you’re practically cutting out all the carbs from your diet. Without carbs, may not get a good variety of fibre, polyphenols, antioxidants, vitamins, and minerals that come along with carbohydrate containing foods.
  • Energy – Most of our body’s energy should from carbs (45 to 65% to be exact). So when you drop it down to 5%, you are depriving your body from its most important energy source. While some people report feeling great on a keto diet, NOT everyone is the same! I’ve had many clients try the keto diet, and feel awful. If you’re one of those people – you should ask yourself, should you PURPOSEFULLY doing something that the internet tells you is good, when your body is screaming NO! Your body is wiser than diet-trend bloggers – c’mon people. Common symptoms include headaches, leg cramps, and heart palpitations. When you feel tired and grumpy all the time, you know your body needs more carbs to run its engines.

Why would someone feel better on a keto diet?

In general, studies have found that carb exclusion diets have limited effectiveness towards IBS patients, except those with fructose and lactose malabsorption – and in those cases, excluding specific carbohydrates has efficacy4.

Often times, I find people may feel better on a keto diet because FODMAP’s are a source of carbohydrate. You’re going to be removing a lot of FODMAP’s inherently on the keto diet, because you’ve removed the bulk of your carbohydrate. However, this is unnecessarily limiting – for all the reasons above! Ask yourself- can you see yourself doing this diet, day in and day out, for the rest of your life? If the answer is no, you should find another way to manage your IBS.

What other ways can we manage IBS?

The best evidence around IBS management exists with the low FODMAP diet. The low FODMAP diet eliminates foods that contain a complex of short chain carbohydrates, which are common culprits of gas and bloating when they are poorly absorbed in the gut and fermented by colonic bacteria. By going on the low FODMAP diet for a short period of time, we can identify potential triggers of IBS, and adjust intake and lifestyle around this. Our goals are to prevent or minimize gastrointestinal symptoms and to promote normal bowel function. Here are a few ways that we suggest that will help you better manage your IBS.

Consider a Low FODMAP diet (but do it properly!)

FODMAP stands for Fermentable Oligosaccarides, Disaccarides, Monosaccharides and Polyols. FODMAPs are a group of fermentable carbohydrates that are poorly absorbed in the small intestine and then fermented by colonic bacteria. Eating high FODMAP foods may contribute in some individuals to their IBS symptoms5,6.

By reducing FODMAP intake for a short period of time, and then strategically reintroducing FODMAP’s, you can identify your upper tolerance.

It should be noted that you should NOT follow the low FODMAP diet long term as it can be detrimental to gut health – for the same reasons the keto diet is! 

However – the low FODMAP diet is NOT meant to be long term – strategic reintroduction is KEY – whereas the keto diet is ‘apparently’ forever. (Ya – we will all talk in 3-4 years and have a good laugh over it. Prediction: Next trend is plant based – the polar opposite, and a diet which I love at its least-extreme)

In my practice, I see many people implement the low FODMAP diet incorrectly –and often believe it won’t work for them. However, I often find when implemented properly, under the guidance of a dietitian, and taking into account other factors that contribute to IBS, it can help to reduce symptoms immensely.

Adequate and Consistent Fibre Intake

Research has found that gut bacteria imbalance (more bad gut bacteria than good bacteria) may result in stool irregularities. Therefore, consuming a healthy diet with adequate fiber (such as whole grains, fruits and vegetables) can contribute to IBS management7.

We recommend clients to aim for 25 to 38 grams of fiber per day consistently to help normalize how quickly things move through your gut – but again, is only one piece of the IBS puzzle. Often times, other measures are required alongside consistent fibre intake to promote symptom relief.

Dine in a Relaxed Eating Environment

Stress is one of the potential triggers for IBS. Proper stress management is recommended to help better manage IBS symptoms. One way to reduce stress is to eat your meals in a relaxed environment. Play some soft music in the background and turn off your TV, smartphones, and laptop. Try to eat slowly and chew your food thoroughly. By eating in a relaxed environment, you will be more mindful of the amount of food you are eating. Chewing your food sufficiently could improve your digestion and reduce the prevalence of IBS symptoms.

Be Medication Informed

There are many different medications out on the market to help alleviate symptoms. I always say, I’m a food first dietitian, and that bringing in medications alongside discussion with your physician or gastroenterologist may help to provide additional symptom control and management.

There are a variety of different drugs that may be beneficial to someone with IBS – but should be used strategically, as part of a treatment plan. Some drugs help to slow or speed up transit of food through your gut. Others help to soften stool. Over the counter supplements such as peppermint or certain strains of probiotics may also provide symptomatic relief for IBS. However, before using any drugs to manage your IBS, you should consult your doctor and carefully review for potential side effects associated with them – as well as understanding that they’re only a small part of adequate IBS treatment.

By adopting the different methods listed here into your lifestyle, you can better manage your IBS symptoms and re-establish a trusting relationship with your gut. Over time, you will have better control over your symptoms and defecation patterns. This will give you the freedom to enjoy the better things in life rather than visiting the washroom frequently.

Can a keto diet help your IBS (irritable bowel syndrome)? Andrea Hardy, registered dietitian and gut health expert talks about the science behind the ketogenic diet and IBS, and what you need to know before you start a keto diet. | Ignite Nutrition Inc. Calgary Alberta Registered Dietitian Nutritionists

Co-Written By Amy Pun, University of Alberta Nutrition Student


  1. Levy, R. G., Cooper, P. N., Giri, P., & Pulman, J. (2012). Ketogenic diet and other dietary treatments for epilepsy. Cochrane Database Syst Rev, 3(CD001903).

  2. Astrup, A., Larsen, T. M., & Harper, A. (2004). Atkins and other low-carbohydrate diets: hoax or an effective tool for weight loss?. The Lancet, 364(9437), 897-899.

  3. Austin, G. L., Dalton, C. B., Hu, Y., Morris, C. B., Hankins, J., Weinland, S. R., ... & Drossman, D. A. (2009). A very low-carbohydrate diet improves symptoms and quality of life in diarrhea-predominant irritable bowel syndrome. Clinical Gastroenterology and Hepatology, 7(6), 706-708.

  4. Cabre, E. (2010). Irritable bowel syndrome: can nutrient manipulation help?. Current Opinion in Clinical Nutrition & Metabolic Care, 13(5), 581-587.

  5. Halmos, E. P., Power, V. A., Shepherd, S. J., Gibson, P. R., & Muir, J. G. (2014). A diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology, 146(1), 67-75.

  6. Roest, R. D., Dobbs, B. R., Chapman, B. A., Batman, B., O'brien, L. A., Leeper, J. A., ... & Gearry, R. B. (2013). The low FODMAP diet improves gastrointestinal symptoms in patients with irritable bowel syndrome: a prospective study. International journal of clinical practice, 67(9), 895-903.

  7. Bosaeus, I. (2004). Fibre effects on intestinal functions (diarrhoea, constipation and irritable bowel syndrome). Clinical Nutrition Supplements, 1(2), 33-38.