Why am I farting so much on a vegan diet!?

September 6, 2018

After a bit of thinking and planning, you’ve decided to make the switch to go vegan. You’ve been testing lots of different recipes and experimenting with this new group of protein foods called legumes.

You’ve been doing really well, trying chickpea burgers, adding kidney beans to your salad and having lentil dahl for dinner. All of a sudden, you’ve noticed the room is starting to smell quite a lot, a significant amount of farts coming out the other end and people around you giving you strange looks.


Why do we fart?

The majority of our gas (farts) come as a result of the fermentation of undigested foods in the gut. These foods primarily include short-chain carbohydrates which aren’t completely absorbed in the small bowel and then enter the colon.

Inside the colon, there is a large amount of bacteria that ferment these foods, which as a result, release methane, hydrogen and carbon dioxide in varying amounts.

This mixture of gases, becomes the smell of our farts.


Will I fart more as a vegan?

Possibly, yes. Vegan diets are especially rich in these non-absorbable (fibre-rich) carbohydrates.

When we start a vegan diet, we generally increase these fibre-rich foods, especially vegetables and beans. So although our eco and animal-friendly plant-based diets are well known for their benefits in reducing the risk of cardiovascular and other chronic diseases, it is largely recognised that these foods significantly increase our gas production.

This especially occurs when we first increase foods such as broccoli, lentils and beans in our diet, which are packed full of these non-absorbable fibres that our gut bacteria is just not used to yet.

There is also research to suggest that gas production is related to the metabolic activity of the microbiota (or gut bacteria) that resides within our gut.

Some studies have shown that imbalances in gut bacteria cause more frequent and odorous flatulence.

Some individuals, in particular those suffering from Irritable Bowel Syndrome (IBS), have difficulty digesting these short-chain carbohydrates.

As a collective, these foods are called FODMAPS.

For individuals with IBS, FODMAPS can cause symptoms such as persistent abdominal pain, bloating, constipation and diarrhoea.

Individuals with IBS can undertake a low FODMAP diet which includes an elimination stage followed by a reintroduction stage with the help of a dietitian. It is important to do this with professional support due to the diet being quite complex and restrictive (especially if you’re also vegan!) and should not be followed as a long-term diet.

Interested in learning more? Read our post on the Vegan Low FODMAP Diet.



What are the vegan fart remedies?

Adapt to fibre slowly. The main complaints of excessive gas, abdominal pain and bloating generally come when individuals have significantly increased their fibre intake over a short period of time, without letting their bodies adapt.

Don’t get me wrong, fibre is very important for our body and linked with producing a high level of healthy gut bacteria. However, fibre can come with some negative side effects when increased too quickly. Be mindful of foods such as lentils, chickpeas, kidney beans, onion, garlic and leek, broccoli and cauliflower, as these are often the biggest causes of smelly farts.

At the end of the day, farting is a good thing and is often a sign of a healthy gut (even if your nose does not agree!).


This blog was written by PNW Clinic founder Kiah Paetz. You can read more about Kiah here.

If you’re following a plant-based or vegan diet and want to make sure you’re meeting all your nutritional needs, take control and book in to see one of our expert vegan dietitians.

Let’s get in touch!


Phone: 07 3040 6911
Fax: 07 3036 5824


  • This field is for validation purposes and should be left unchanged.