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Keto and IBS: Is the Keto Diet Gut Friendly?

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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, as a registered dietitian, to unravel the mystery of the keto diet. I’ll first explain the definition of a keto diet. And of course, we’ll ultimately review whether it’s something you should be considering to manage your IBS symptoms. Spoiler alert – it’s complicated and probably not a great fit for everyone! Let’s find out why.

Table of Contents

  1. What is a keto diet?
  2. How does the keto diet help your IBS symptoms?
  3. The problems with low carbohydrate diets
  4. Why would someone feel better on a keto diet?
  5. What other ways can we manage IBS symptoms?

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 frequency.1 BUT, you’ve probably seen it around the internet touted as the ‘if paleo didn’t work – you should try this’ kinda diet. (cough cough FAD DIET 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 metabolism.2 Not to mention, food fixation, and a general dislike for any person who liberally eats carbohydrates.

A charcoal coloured plate on a white table. There is a fried egg, a sliced avocado, about 4 slices of bacon, a few cherry tomatoes and some salad greens on the plate. There is a text box that reads "keto and IBS: is the keto diet gut friendly?"

How does the keto diet help your IBS symptoms?

IBS is a functional gut disorder. People with IBS often experience IBS symptoms like constipation, diarrhea or cycles of both. The exact cause of IBS is still unknown. However, research suggests that a family history of IBS, other digestive disorders, gut infections, dietary pattern, stress, and gut bacteria imbalance may all be associated. IBS symptoms can be triggered by foods that differ between individuals.

High FODMAP (fermentable carbohydrate) foods are known, through evidence based research to cause IBS symptoms. In those with IBS symptoms, when high FODMAP foods are 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 symptoms. 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 symptoms.

The questions you SHOULD be asking are: 

  • Is that extreme of a diet needed to get similar IBS symptom relief?
  • Did the study ACTUALLY measure what we think it measured? Was it the removal of FODMAP’s (fermentable carbs) that resulted in IBS 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 problems with low carbohydrate diets:

1. 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, and lettuce will become your best friends. 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.

2. 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.

3. Adequate fibre

When you use a keto diet to manage your IBS symptoms, you’re practically cutting out all carbs. Without carbs, you may not get a good variety of fibre, polyphenols, antioxidants, vitamins, and minerals that your body needs.

4. 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 be 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 of low carb diets 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. In those cases, excluding specific carbohydrates has efficacy.4

Often times, I find people may feel better on a keto diet because FODMAPs are a source of carbohydrate. On the keto diet you’ve removed the bulk of your carbohydrate. Therefore, you’re going to be removing a lot of FODMAPs. 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 symptoms.

What other ways can we manage IBS symptoms?

The best evidence around IBS symptom management exists with the low FODMAP diet. The low FODMAP diet eliminates foods that contain a complex of short chain carbohydrates. FODMAPs are common culprits of gas and bloating. This is because FODMAPs are poorly absorbed by the gut and fermented by colonic bacteria. By going on the low FODMAP diet for a short period of time, we can identify potential IBS symptom triggers. Then we can 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 symptoms.

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. FODMAPs 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 registered dietitian, and taking into account other factors that contribute to IBS symptoms, it can help to reduce IBS 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 symptom management7.

We recommend clients aim for 25 to 38 grams of fiber per day consistently. This will 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 IBS symptom relief.

Dine in a Relaxed Eating Environment

Stress is one of the potential triggers for IBS symptoms. 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 IBS symptoms. I’m a food first IBS dietitian. Yet, I always say that bringing in medications, alongside a discussion with your physician or gastroenterologist, may help to provide additional IBS symptom relief.

There are a variety of different drugs that may be beneficial to someone with IBS symptoms. But, these 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 symptoms, you should consult your doctor. It is also important to carefully review the potential side effects associated with them. As well as understanding that they’re only a small part of adequate IBS symptom 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 IBS symptoms and defecation patterns. This will give you the freedom to enjoy the better things in life rather than visiting the washroom frequently.

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

FAQs about keto and IBS

Is a low carb diet good for IBS?

In one study, IBS-D patients found some IBS symptom relief with a low carb diet. However, it is important to consider what is missing from the diet when we cut out carbs, and how it affects our gut health long term.

Does keto make IBS worse?

While some people report feeling great on a keto diet many patients report trying the keto diet, and feeling awful. Common symptoms of low carb diets include headaches, leg cramps, and heart palpitations. When you feel tired and irritable all the time this may exacerbate your ability to effectively manage your IBS symptoms.

How do you calm an IBS flare up?

Here are some ways to help calm a bad IBS flare up: 1) ensure you are getting enough fibre, and enough fluid, 2) avoid FODMAPs and other non-FODMAP food triggers, 3) space your meals out and avoid eating large portions at one time, and 4) manage stress. Learn more about how to control IBS flare ups.

Categorized: Gut Health & IBS

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