Keto, Intermittent Fasting & Gut Health – What You Need to Know About The Latest Diet Trends

Keto, Intermittent Fasting & Gut Health – What You Need to Know About The Latest Diet Trends

I am sure you’ve heard the buzz about keto and intermittent fasting.

Though they’re actually quite different, these hot diets have a few things in common that make them especially tempting. They both involve a set of rules. They are both controversial. And they certainly both claim incredible weight loss and health benefits.

But can your sensitive gut handle them?

That’s the question we are answering today. Let’s have a look at each diets’ origins, the research behind them, and whether or not they’re suitable for someone with IBS or IBD, like you!


Intermittent Fasting

Intermittent Fasting (IF) is a diet that recommends alternating periods of fasting and eating. There are no limits on what to eat, only when.

The timing and details of IF vary depending on whose approach you follow. Some suggest alternate day fasting, others limit eating to only short periods of the day. But the general tenet is this. We naturally fast every night when we sleep. By shortening our eating window, we extend this fast. This reduces the insulin in our bodies and we benefit through weight loss, better blood sugar control and a whole bunch of other health improvements… I can see the appeal!

I am not here to comment on intermittent fasting as a weight loss strategy. There is preliminary research to suggest it may be beneficial for some individuals, and whether or not it’s suitable for your health goals is up to you and your doctor.

But there have been some false claims regarding IF and IBS, and I want to clear things up. Listen, I would be thrilled to be able to share another evidence-based tool for the treatment of digestive issues. That is why I created Clairity… To give you every possible strategy to help you break free from symptoms of IBS and IBD! And as a Registered Dietitian, it is important that I have an open-mind when it comes to new research.

Some claim that intermittent fasting improves gut bacteria and reduces digestive symptoms. But the reality is that the research just isn’t there yet. There are a limited number of studies looking at IF and digestive disorders, and very little of that research is in humans.

And let me emphasize, research is important. Especially for a diet this drastic. Research shows us whether something can help improve our health. But maybe even more importantly, it shows us the risks. Without adequate research, you may be following a diet that is doing your gut (and your health) harm.

Another key issue with intermittent fasting is that it only addresses meal timing, and not meal composition. Though it’s not the only factor that contributes to digestive symptoms, the type of food you eat does play a role in digestion. Without addressing your unique food triggers, you are looking at short-term relief, at best.

And as with any diet, I urge you to ask yourself: Is this sustainable? If it’s not something that feels good and that you can sustain long-term, I encourage you to explore a different approach.



The Ketogenic Diet, otherwise known as “keto,” is the latest version of ‘low carb’. Or, more accurately, very low carb and very high fat. It was introduced as a seizure treatment in children with epilepsy and is selectively utilized by healthcare professionals to help treat diabetes, some cancers, polycystic ovary syndrome and other ailments.

Like intermittent fasting, keto has recently gained attention as a weight loss tactic. The idea is to eat a diet as low in carbohydrates as possible. In doing so, our body can no longer rely on glucose to fuel its cells and provide energy to the brain. So, the body turns to fat cells to produce ketones as an alternate energy source. The happy side effect, of course, being weight loss.

Being so low in carbohydrates, keto is naturally free from FODMAPs… Remember those? FODMAPs are those pesky sugars that seem to aggravate digestive symptoms for those of us with IBS and other gut issues.

With all that in mind, keto can be extra tempting for those of us with sensitive bellies who also hold the goal of weight loss. But please be careful with this one.

First of all, it’s an extreme way of eating that should really only be implemented with close monitoring from a health professional.

More specific to your digestion, keto is majorly lacking in fibre. Health Canada recommends the average person consumes 25 grams of fibre per day. And with IBS, this number may be even higher. But keto excludes almost all sources of fibre because they are too high in carbohydrates… That means saying goodbye to fruits, vegetables and whole grains. Without fibre, you may be looking at constipation, distention, gas, plenty of other uncomfortable symptoms, and some long-term health risks, too.

And let’s not forget that permanent elimination of FODMAPs is not our goal. High FODMAP foods provide important nutritional variety. And they provide prebiotics to help our gut bacteria thrive and our digestion operate effectively.


So, what can you do?

If your goal is better gut health and a reduction in digestive symptoms, keto and intermittent fasting may not be the diets for you.

As we discussed, the research is not strong enough to show that they are effective for treating IBS or IBD. And without adequate research, we just don’t know what harm we may be causing.

But there are so many evidence-based strategies that work. Here’s what you can focus on instead.


  • Rather than fasting, time meals and snacks 3-4 hours apart. This allows the migrating motor complex in your gut, also known as your gut muscles, to operate effectively. This helps reduce uncomfortable symptoms between eating.
  • Build balanced plates with carbohydrates, fat and protein. Each nutrient plays an important role in your body and a well-balanced diet will help you feel your best.
  • Learn your IBS triggers. This is a big one. The foods the cause digestive symptoms for you are different than those that aggravate your partner, sister, or friend. Learn more about how to do this here.


Diets like keto and intermittent fasting are so tempting because they promise a quick fix. It would be so much easier to follow a set of rules on what to eat to feel and look amazing. I get it. But our bodies are unique. Our symptoms are complex. And there are so many other factors at play outside of food.

That is why I believe in investing your energy in a digestive health dietitian or a program like Clairity. We won’t give you a set of strict rules or tell you exactly what to eat. Instead, we empower you with the tools and knowledge you need to eat and live for good digestion. We guide you through our evidence-based process and you’ll learn how to eat with confidence. For life. 

If you are going to try keto, intermittent fasting or any other diet, please do so under the guidance of your physician or a healthcare provider.

I hope this helps you get clear on your path forward. As always, contact us anytime if you have questions or if you’d like to explore our program!

Wishing you well, always,

Stephanie Clairmont, MHSc, RD
Founder, Lead Coach
Clairity Digestive Program