A Vegan Diet for IBS - THE IBS DIETITIAN

A vegan diet for IBS could be quite restrictive. You may worry how you will manage to meet your nutritional requirements. Luckily there are plenty of low FODMAP plant-based foods that you can continue to enjoy.

This article will discuss how you can enjoy a low FODMAP vegan diet. We will also provide practical tips to ensure your diet is nutritionally balanced.

Table of Contents

Is a vegan diet good for IBS?

There is no evidence that a vegan diet can improve IBS symptoms. But do not worry! If you are wanting to follow this diet for your own ethical reasons, there are ways around these potential triggers.

Is a vegan diet for IBS bad?

A vegan diet may contain higher amounts of fibre and FODMAPs which can worsen IBS symptoms (3, 4).

Is a vegan diet good for health?

A vegan diet avoids all animal-based products. They are based on plant foods and can provide many health benefits. A vegan diet could reduce your risk of (1):

Heart disease
Type 2 diabetes
Obesity
Certain cancers

A plant-based diet can also increase your intake of fibre and polyphenols, a beneficial plant compound. This can boost the diversity of your beneficial bacteria and improve gut health (2).

How to follow the low FODMAP diet when you are vegan

A vegan diet for IBS is restrictive as you have the restrictions of both the vegan and low FODMAP diet. Failure to plan your diet properly can leave out essential macro and micro-nutrients, making it challenging to meet your daily nutritional requirements. This can lead to a deficiency of protein, calcium, vitamin B12, iodine and omega-3 fatty acids (5).

However, a low FODMAP vegan diet for IBS can be done with the right support and advice from a dietitian. This is essential to maintain a balanced, nourishing diet whilst providing symptom relief.

Here are some tips on how to reduce high FODMAP plant foods while ensuring that you meet your nutritional requirements:

Low FODMAP vegan protein

Protein is needed to grow and repair your body tissues (6). The main source of protein in a vegan diet comes from beans and legumes such as chickpeas, lentils and beans. However, these are often high in galacto-oligosaccharides (GOS) and fructans, causing IBS symptoms.

Fortunately, there are still many low FODMAP, vegan sources of protein to choose from:

Firm tofu, tempeh (avoid wheat, barley, onion, and garlic)
Chickpeas, lentils, beans (choose canned versions and rinse in water before consuming)
Nuts, e.g. almonds, hazelnuts, peanuts, brazil nuts, pine nuts, walnuts
Seeds, e.g. chia, poppy, pumpkin, sesame, sunflower
Nut/seed butter, e.g. peanut, almond, pumpkin, sunflower
Quinoa and buckwheat
Edamame
Quorn products (avoid garlic and onion)

You should also check which portion sizes are low FODMAP by using the Monash app.

Here are some high protein, low FODMAP vegan recipes that you can try to help you meet your daily requirements:

Carbohydrates

Whether you are following a vegan diet or not, carbohydrates provide the primary source of energy for your body (7). These can be high in fructans, and therefore may trigger your symptoms and should be avoided on the low FODMAP diet.

There are many IBS-friendly carbohydrate sources that you can add to your diet. Please check the low FODMAP serving sizes for these. Here are some examples:

Examples of a carbohydrate-rich, low FODMAP vegan snacks include:

Popcorn
Crisps
Low-FODMAP fruits
Nairn’s biscuit breaks (oats Grahams and oats, chocolate & coconut flavours)
Schär digestive biscuits
Plain potato chips/nacho chips

Here are some delicious carbohydrate-based, low FODMAP vegan recipes:

Vegan Low FODMAP sources of Calcium

Calcium is essential to keep your bones and teeth strong (8). Adults aged 19 – 64 require 700mg of calcium daily (9).

Suitable plant-based alternatives that can provide a source of calcium include:

Certain plant-based milks
Vegan cheese (ensure it is fortified and no FODMAPs e.g. garlic and onion added)
Low FODMAP plant-based yoghurts

Remember to check that the above products are fortified with vitamin b12, vitamin D, calcium, and iodine.

Other plant-based calcium sources include:

Low FODMAP green leafy vegetables, e.g. bok choy, collard greens, and kale
Soy products, e.g. firm tofu, tempeh
Seeds, e.g. chia seeds
Nuts, e.g. almonds

Please check for the recommended low FODMAP portion sizes on the Monash app.

Vegan Low FODMAP Sources of Iron

Iron is essential for making red blood cells and transporting oxygen in your body (10). Iron requirement differs depending on age and sex (11):

Men older than 18 yrs: 8.7mg/day
Women aged 19-50: 14.8mg/day
Women older than 50 yrs: 8.7mg/day

Plant-based sources of iron (non-heme iron) are less well absorbed than animal-based iron (heme iron).

Here are some low FODMAP vegan sources of iron (per 100g) (12, 13):

1.2 mg firm tofu (low FODMAP at 170 g)
2.1 mg tempeh
1.6 mg spinach
1.3 mg canned lentils (low FODMAP at 46g)
1.3 mg canned chickpeas (low FODMAP at 42 g)
10.4 mg sesame seeds
6.4 mg sunflower seeds
3 mg brazil nuts
3.2 mg hazelnuts (low FODMAP at 15 g)
2.3 mg edamame (low FODMAP at 90g)
1.5 mg quinoa

Vitamin C has been shown to increase iron absorption (14). So, try to incorporate foods high in vitamin C whilst having foods high in iron. Low FODMAP foods high in vitamin C include:

Citrus fruits, e.g. oranges, pineapples, lemons, limes
Dark green leafy vegetables
Bell peppers
Strawberries (click here for low FODMAP serving sizes for strawberries)

Vegan Low FODMAP sources of Vitamin B12

Another vitamin that can be hard to meet when following a vegan diet is vitamin B12. This is because B12 is not found in plant foods other than fortified cereals (15). B12 is required to form red blood cells and DNA, which is essential for healthy blood and brain development (16).

Adults who eat animal products require 1.5 micrograms a day of vitamin B12 (17). The absorption of vitamin B12 improves if you eat food sources containing it regularly (18). So, it is recommended that vegans have are 3 micrograms to ensure that you are meeting your requirements (19).

Here are some low FODMAP vegan sources of vitamin B12:

Fortified nutritional yeast
Plant based fortified low-FODMAP milk
Low FODMAP cereals – remember to check that they have been fortified
Buckwheat noodles

Vegan Low FODMAP sources of Omega 3 fatty acids

Omega 3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are essential fats. This means that your body cannot make them on its own. These fats are found in fish, primarily in oily fish (17). They are essential for heart health and reduce your risk of cardiovascular disease (18).

Alpha-linolenic acid (ALA) found in plant-based sources can be used to make EPA and DHA (19). This process happens slowly, producing only small amounts (20).

Low FODMAP plant-based ALA sources include (21):

Certain oils, e.g. flaxseed, walnut, soya, canola
Seeds, e.g. chia, flax, pumpkin, hemp
Low FODMAP nuts, e.g. walnuts
Green leafy vegetables
Edamame
Firm tofu

Supplementing micronutrients for a vegan diet for IBS

It can be tricky to meet these requirements whilst following a vegan diet for IBS. Supplementing can ensure that you are consistently meeting your requirements. VEG1 is a chewable multivitamin developed by The Vegan Society. It contains:

Vitamin B12 (25µg – 1,000%)
Vitamin D3 (20µg – 400%)
Iodine (150µg – 100%)
Selenium (60µg – 109%)
Vitamin B2 (1.6mg -114%)
Vitamin B6 (2mg – 143%)
Folic Acid (200µg – 100%)

Summary

Maintaining a vegan diet while following a low FODMAP diet is possible. It will require more planning to ensure that you meet your nutritional needs!

Vegan diets can provide many health benefits, such as reducing the risk of heart disease, diabetes, obesity and certain cancers. However, It can be low in certain nutrients such as protein, iron, calcium, vitamin B12 and omega-3 fatty acids if not planned correctly.

It can be restrictive and challenging to follow whilst on a low FODMAP diet. So, it is recommended to work with a dietitian to ensure you are getting all these essential nutrients whilst on a low FODMAP diet!

Article written by Leeona Lam, reviewed by Beth Willson Specialist Gastroenterology Dietitian BSc Hons and Kirsten Jackson Consultant Dietitian BSc Hons, RD, PG Cert

Bethany Willson Specialist Dietitian BSc Hons

Beth is UK HCPC Registered Dietitian who specialises in gastrointestinal surgery. Beth graduated from University of Surrey in 2020 with a degree in Nutrition and Dietetics.