Here’s What You Need to Know from Jocelyn Harrison, MPH, RDN

Q: For someone who may not be familiar with the low FODMAP diet, could you briefly explain what it entails and how it helps manage gastrointestinal symptoms?

A low FODMAP diet is a three-step dietary protocol, not a long-term diet. Its purpose is to minimize or eliminate symptoms associated with Irritable Bowel Syndrome (IBS) and Small intestinal Bacterial Overgrowth (SIBO) as well as identify specific FODMAPs that are triggering these symptoms. Common symptoms can include abdominal pain, cramping, abdominal bloating and distension, excessive gassiness, diarrhea, constipation, nausea, and loss of appetite. The protocol begins by eliminating high FODMAP foods to see if FODMAPs are the cause of symptoms.

FODMAP is an acronym for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These are a group of short chain carbohydrates (sugars and fibers) that are poorly absorbed in the small intestine.

The protocol involves three steps:

1. Eliminate: Remove all high FODMAP foods and monitor symptom improvement.

2. Reintroduce: Slowly reintroduce one FODMAP category at a time to determine which triggers symptoms.

3. Personalize: Liberalize the diet to include all FODMAP groups that do not cause symptoms.,

FODMAPs are beneficial for gut health, so the goal is to minimize restrictions and reintroduce as many plant foods as possible, which contain fibers and phytochemicals important for overall health.

Q: Many people assume a low FODMAP protocol is challenging or impossible to follow if you're plant-based. Can you explain why this is a misconception and how it's actually possible?

It’s absolutely possible to follow a low FODMAP diet while being 100% plant-based. The misconception is often due to concern about how plant-based individuals on the low FODMAP diet will get all of their nutrient needs met. Animal foods like meat, poultry and fish contain little to no FODMAPs allowing an omnivorous person on the protocol to make up for any restricted foods through an increase in animal foods. However, that is not necessary or acceptable for someone who is plant-based.

There is a wide variety of foods that can be eaten on the low FODMAP protocol and many are protein-rich like tofu, tempeh, nuts, seeds, small quantities of beans, peas and lentils and whole grains. In addition, plant foods provide all 20 amino acids, so all plants contain protein. The key concern is that some protein-rich foods like beans may need to be served in low FODMAP portion sizes, but that’s manageable.

Q: What are some of the common challenges plant-based individuals face when trying to follow a low FODMAP diet?

One of the challenges, and this applies to anyone following a low FODMAP diet, is figuring out what to eat for breakfast, lunch, dinner, and snacks that are indeed low FODMAP. However, if you work with a registered dietitian who is trained in the low FODMAP protocol and preferentially is also familiar with the plant-based lifestyle, they can help the patient craft those meals and combine foods in a way that ensures each meal is low FODMAP. This support is especially important during the elimination phase (step one) and step two.

During step two, you continue to eat low FODMAP while introducing one high FODMAP food group at a time. For the most part, it’s essential to keep your meals consistently low FODMAP. This doesn’t mean eating the same thing every day at each meal, but rather understanding how to combine foods properly in a meal.

Q: Could you share a few plant-based foods that are both low FODMAP and suitable for someone with IBS or GI issues? Could you share some examples of quick, easy, and nutritious plant-based low-FODMAP meals or snacks that someone with IBS can incorporate into their daily routine?

There are a handful of fruits that have no FODMAPs at all. What I like to do with my patients is give them a list of what they can eat on the low FODMAP protocol, not what they can’t eat. For example, blueberries contain no FODMAPs, so they’re a great option. Papaya is another fruit with no FODMAPs, as well as clementines. These fruits can be eaten without restriction.

There’s a much more extensive list of low FODMAP fruits that can be added, but we just have to be careful about the amounts of those fruits. For instance, strawberries contain the FODMAP fructose, so we’d only want that meal to include one fructose-containing food. For example, someone might have oatmeal for breakfast, which is low FODMAP if made with regular rolled oats (not quick cooking). They could have that oatmeal with blueberries and strawberries. Bananas are also low FODMAP, but only a third of a ripe banana is recommended, as it contains a different FODMAP called fructan. So, someone could add a limited number of strawberries, a small amount of banana, and blueberries to their oatmeal breakfast, and that would be a low FODMAP breakfast. This is just an example of how we combine foods to make a low-FODMAP meal.

Q: Are there any plant-based food groups or ingredients often overlooked when creating a low FODMAP meal plan?

I think one often overlooked plant-based food when creating a low FODMAP meal plan is regular potatoes. Unpeeled potatoes are actually low FODMAP and a good source of starch for your meal. A balanced meal should include a protein-rich food, a starch, and be mostly made up of fruits and vegetables. There is actually a long list of vegetables that are low FODMAP, you just need to have the appropriate list.

I am trained by Monash University, who created the low FODMAP protocol, and they created an app that allows you to look up specific foods for their FODMAP contents. They regularly update their app. My partners and I have compiled a list of the foods that are low or no FODMAP, which includes fruits, vegetables, nuts and seeds, grains, and pulses/legumes like peas, lentils, and beans. A lot of people think they can’t eat beans like chickpeas on a low FODMAP diet because beans are known to cause gas, but you can actually add a fourth of a cup of chickpeas to a meal. Chickpeas contain the FODMAP called GOS (galacto-oligosaccharides), and many beans and nuts contain GOS. As long as it's the only food in the meal that contains GOS and you eat it at a low FODMAP serving size, it’ll be fine.

Q: Are there any common nutrient deficiencies that plant-based people with IBS should be aware of, and how can they address them while sticking to a low FODMAP approach?

Regardless if someone is on the low FODMAP protocol, if they are 100% plant-based, they need to supplement with vitamin B12, either through fortified foods that have added B12 or a good quality B12 supplement. This is because B12 is primarily derived from animal-sourced foods.

I strongly encourage individuals to work with a registered dietitian, no matter their eating pattern, to make sure all of their nutritional needs are met. Some common nutrients of concern for anyone, including those on a plant-based diet are calcium, iron, zinc, iodine, vitamin D, and vitamin B12.

Q: How do you work with patients to maintain a balanced, sustainable plant-based diet while managing IBS symptoms over time?

To help my patients maintain a balanced, sustainable plant-based diet while on the low FODMAP protocol, I provide them with resources so they know what to eat, how to compose meals, how to plan and shop for food and how to eat at restaurants and when traveling. I provide several low FODMAP food guides, including a list of all the whole plant foods they can eat, herbs, herbal teas as well as snacks and other resources. I also often show patients photographs of meals that other patients have created while following the low FODMAP protocol. It’s really fun to show examples because it makes the plan feel more relatable. A lot of times, when people can see what others are eating, they think, "Oh, I can do that!"

There are also many great low FODMAP resources available. For example, FODY Foods is a company that makes condiments, like ketchup or marinara sauces, that don’t contain garlic, onion, or other high FODMAP ingredients. Unfortunately, garlic and onion contain the FODMAP fructan and can be problematic for some.

Q: How can people manage the transition from a typical high FODMAP plant-based diet to a low FODMAP version without feeling restricted or overwhelmed?

Work with a registered dietitian who has the expertise to help with that transition. With the proper resources and guidance most individuals find that it is not that difficult.

Q: What advice do you have for people who are newly diagnosed with IBS or SIBO and are also committed to a plant-based lifestyle?

Definitely find a plant-based dietitian who can help you because the FODMAP protocol is nuanced. There are also more things that are needed to ensure good gut health. Eating low FODMAP is not curative. We have to look at all the factors that could be exacerbating symptoms. For example, are meals high in fat, are meals and snacks eaten at consistent regular intervals, is one getting adequate fluids, how much stress is the individual dealing with, are there other diagnoses. I can tell a lot about someone by their symptoms and daily habits. That’s why we always start with a thorough nutritional and lifestyle assessment. There’s a lot more that goes into healing gastrointestinal issue than just the low FODMAP protocol.

Q: What steps can we take to raise awareness about the importance of plant-based options in low FODMAP meal plans, especially for those managing IBS or other GI disorders?

This blog came about because some plant-based IBS patients were unable to find dietitians who were willing to help. More dietitians need to know that you can follow the low FODMAP protocol and be 100% plant-based. It's important to raise awareness so that people managing IBS or other GI disorders can receive the support they need while maintaining their plant-based lifestyle.

Q: What would you like to see change in the way IBS and GI disorders are managed from a nutritional standpoint, especially for plant-based individuals?

Well, unfortunately, we live in a time of extreme misinformation and conflicting information. I’m not sure what we can do about that, but I do know that getting more people directed to reliable, credentialed sources of real information is helpful. I recommend downloading the Monash University FODMAP app which has a directory of trained dietitians. Reach out to several listed and ask if they will work with someone who's plant-based. Not every dietitian is well-versed in plant-based diets, so it’s important to find someone who is.

Q: Research continues to analyze and refine the Low FODMAP diet, with studies focusing on how to tailor it to individual needs. Are there any new research findings related to IBS, GI disorders, or plant-based diets that you're particularly excited about?

You know, I'm particularly excited that the American Gastroenterological Association is now saying that probiotics are not recommended for the general public. I think that is a real win because there's a lot of information that makes people think they should be taking probiotics, and that can often exacerbate GI problems instead of fixing them. Recommendations to take probiotics for general use or for certain cases are just too far ahead of the science.

The other thing is that food sensitivity testing is really ahead of the science and not reliable. That message needs to get out because I think it sends people down a lot of paths. Also, people need to know that they can do the low FODMAP protocol and not be overly restrictive. In addition, we now even have FODMAP-Lite, which is an easier version of the protocol that's also called FODMAP-Gentle.

Key takeaways:

Low FODMAP & Plant-Based — Yes, You Can Do Both!

1. The Low FODMAP Diet is a Temporary Tool — Not Forever.

It’s a 3-phase process (Elimination → Reintroduction → Personalization) designed to identify triggers and expand your diet long-term.

2. 100% Plant-Based Low FODMAP is Absolutely Possible without being Overly Restrictive.

There are plenty of low FODMAP plant proteins like tofu, tempeh, nuts, seeds, certain legumes (in small amounts), and whole grains. No need to rely on animal products.

3. Portion Size + Food Combining Matter Most.

Many plant foods are low FODMAP at specific amounts. Beans, fruits, veggies, and grains can all fit when portions are right and foods are combined thoughtfully.

4. A Dietitian Makes This Easier.

Working with an RDN helps prevent nutrient gaps (B12, iron, zinc, calcium, omega-3s), ensures meal variety, and makes the reintroduction phase much more clear and successful.

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