Keto for Gut Health & IBS?

The keto diet or ketogenic diet is a high fat, low protein and very low carbohydrate diet. It was created originally as a medical diet for the treatment of epilepsy, however recently it has become popular diet that it seems everyone is jumping on the bandwagon. The diet has been hailed for weight loss, mood, and gut health, now for today we are only going to focus on the gut health side of things otherwise we will be here all year, I do have a brief summary on instagram here.

The ketogenic diet in short is an incredibly restrictive low carb diet which can be as low as 20g of carbs per day, typically fat makes up to about 80% of the diet and the remainder is protein.  

When we look at gut health we will look at two specific aspects. Firstly, we will look at overall gut health and then specifically for IBS.

Gut health refers to having a healthy and thriving microbiota and our diet plays a large role in this. Some of the key aspects of diet that are associated with gut health are: adequate fibre (30/day), omega-3 fatty acids and polyunsaturated fats, limiting saturated fats, plenty of polyphenols from brightly coloured fruits and vegetables, avoiding excessive amounts of animal protein, limiting highly refined foods and including some pre and probiotic foods. So where does keto fit in with this? Well it doesn’t really. A keto diet makes fibre intake challenging, polyphenol intake isn’t as easy and saturated fats typically creep up.

What about IBS? There is very little evidence for the use of the ketogenic diet in IBS, there is one study which was completed in those with IBS-D (which mind you was funded by Atkins). This study found those with diarrhoea predominant IBS saw some symptomatic improvement with a low carbohydrate diet, however this study has not been replicated and we cannot base too much off one study, additionally this study didn’t look at the effect this diet has on the microbiome of the participants plus their long term symptom  control, and ability to manage the diet long term.

Further, a low carb diet is likely going to be a low fodmap diet too so the benefits of the low carb diet could simply be attributed to a low fodmap diet which has proven to be effective in particular with those with IBS-D. It is hard to differentiate if these people saw improvements because their fodmap intake was lowered or their carb intake.

So what’s my opinion? Based on where the evidence stands at this point in time I do not support the use of the ketogenic diet for a healthy gut or in irritable bowel syndrome.

Why I do not recommend Keto Diet for Gut Health:

  1. Sustainability - the ketogenic diet doesn’t allow for much fun with food and it is incredibly sensitive which means long term sustainability is low. A healthy diet is one that you enjoy and can follow long term.

  2. Variety - The keto diet like i mentioned is restrictive which means that you cannot get a wide variety of foods and fibres which is what is the primary driver for a diverse microbiome. Things like starchy vegetables, fruits, legumes and wholegrains have shown numerous benefits for the health of the intestinal microbiome.

  3. Fibre - As mentioned fibre is so hard to achieve on a low carb diet, if carbs are 20g per day it is very challenging to get adequate fibre for good gut health.

  4. High Fat - A high fat diet can have quite severe and negative effects in those with diarrhoea predominant IBS so for some the ketogenic diet can lead to more loose stools. As mentioned earlier we need to be mindful of the types of fats too

  5. Restrictive - Stress is a huge trigger for IBS and can negatively affect the gut and microbiome. If the diet becomes a source of stress because you are constantly worried about if the food is low carb, or what to eat or feeling like you’re missing out on other foods, then it isn’t going to do you any favours.

As always, you need to find what works for you personally but what I want you to know is that is simply is not necessary to go on a keto diet to improve gut health or reduce symptoms of IBS and there may even be adverse effects on the microbiome of doing so.