Is a Low FODMAP Diet a Healthy Diet?

This is a question I get a low from my clients, worried that this may be just another fad diet. The low FODMAP diet was created by the researchers at Monash University in Australia to alleviate symptoms in people with Irritable Bowel Syndrome (IBS). It is currently considered the best dietary approach for this condition and several research studies have shown it is successful in 50-80-% of people with IBS. 

The answer to the question “is the low FODMAP diet healthy” depends on how it is implemented. Let me digress for a moment to a better-known diet concept, that of a vegan diet. Most people would think that the vegan diet is very healthy as it brings to mind pictures of environmentally friendly, animal-loving people feasting on salads, nuts, and tofu.

However, the definition of vegan diet verges on what it excludes – all animal products – rather than what it includes – plant-based foods. You could, in principle, be eating French fries, cookies made without eggs or butter and drink sodas and you would be considered a vegan. Although I have exaggerated with this example (at least I hope so!), you get the idea: having a bagel with jam for breakfast, a vegan burger on a white bun with lots of ketchup for lunch and a big plate of pasta with tomato sauce for dinner may be closer to what uninformed vegans may be eating and hardly be called a nutritious diet.

Going back to the low FODMAP diet, whether it is healthy or not depends more on what you include than what you exclude. The low FODMAP protocol teaches you to avoid high FODMAP foods (at least during the elimination phase) or minimize them according to tolerance once you have figured out your own personalized FODMAP diet. Many people, however, end up avoiding all high FODMAP foods long term either because they are afraid of re-challenging them or they don’t know that the low FODMAP diet is not supposed to be a life-long diet. And, especially during the elimination phase, they may get into a routine of eating the same few types of vegetables and fruit, or avoiding some foods, like legumes and dairy altogether.

The message I am trying to bring home here is that a poorly planned low FODMAP diet can lacking in important nutrients like calcium and B vitamins, and in fiber. Working with a dietitian who is an expert in the low FODMAP diet can help you avoid this common mistake. Here are a few questions you may ask yourself to get an idea about how healthy your low FODMAP diet is:

1. Am I eating enough fiber?

You don’t need a nutrition software to know whether you are eating enough fiber. Write down what you eat for a few days or a week and look back at your diary: are you eating vegetables at your main meals and at least one snack? Are you occasionally eating low FODMAP servings of canned lentils or chickpeas? Are you including some nuts and seeds? See my 5 Tips to Eat More Fiber on a Low FODMAP Diet for more ideas. 

2. Am I eating enough calcium?

Contrary to common belief, the low FODMAP diet is not a lactose-free diet. It is a low lactose diet and can include small portions of some hard cheese and cream cheese. Small amounts of lactose can be tolerated even by lactose-intolerant people. It is not a dairy-free diet either and you can eat plain lactose-free dairy freely. If you are avoiding dairy for other reasons (allergy to milk protein, ethical reasons, or you just don’t like them), there are many alternative calcium sources. And, yes, even vegans can eat enough calcium if they plan their diet well.

3. Am I eating the colors of the rainbow?

Is your diet white and red (gluten-free pasta and tomatoes) or do you choose vegetables and fruit with all the colors of the rainbow? This is an easy way to ensure you get the bounty of vitamins, minerals, and phytochemicals that vegetables and fruit have to offer. Chard, kale, spinach, carrots, red peppers, eggplant, kabocha and summer squash are just some of the vegetables that have either negligible or small amounts of FODMAPs and can be eaten freely or in fairly large portions. Fruit can be usually enjoyed in half-cup portions per meal or snack. In the spring and summer, strawberries, raspberries, blueberries and cantaloupe or honeydew are great low FODMAP choices, whereas in the fall/winter look for the citrus fruits and kiwi just to name a few.

If you answered yes to all these questions – great job! If you answered no to at least one of these questions, try some of the suggestions above and look at the Monash University Low FODMAP Diet App for guidance on foods and serving sizes.