Low FODMAP Diet Not Working? Top Reasons Plus Troubleshooting Tips

by | Sep 25, 2023 | Low FODMAP

The low FODMAP diet has gained popularity as an effective way to manage the symptoms of irritable bowel syndrome (IBS). It involves avoiding foods high in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs).


While many people experience significant relief from their digestive issues by following this diet, some may find the low-FODMAP diet not working as expected. In this blog post, we’ll explore common reasons for the low-FODMAP diet not working and provide troubleshooting tips to help you find relief from your IBS symptoms.

Infographic with reasons for the low fodmap diet not working

Problem 1: Incomplete Elimination of FODMAPs

One of the most common reasons for the low FODMAP diet not working is not properly eliminating all high FODMAP foods. FODMAPs are present in a wide range of foods, and even small amounts can trigger symptoms in people who are sensitive to them.  Restaurant foods are particularly high in garlic and onion, making limiting fructans a real challenge to those who eat out often.


Troubleshooting Tips:

  1. Re-evaluate your food choices. Review your diet to ensure you haven’t accidentally included any high-FODMAP foods. Hidden sources of FODMAPs can be found in sauces, condiments, and processed foods. If you’re struggling to figure out where the FODMAPs are hiding, try downloading the Monash FODMAP app. The app allows you to search for foods and will tell you if they are high, moderate, or low FODMAP.
  2. Check portion sizes. Even low-FODMAP foods can become high-FODMAP in large quantities. Use the Monash FODMAP app to identify which portion sizes are appropriate.
  3. Be selective when eating out. If you eat out often, read my blog Low FODMAP Eating Out for tips on how to follow the low FODMAP diet at your favourite restaurants.
  4. Be mindful of your FODMAP “bucket”. Think of your FODMAP tolerance like a bucket. You can fill it up to a certain amount without getting symptoms, but once you fill it too much, it overflows. In the case of FODMAPs, you may find that throughout the day, small amounts of FODMAPs add up and “overflow” your FODMAP bucket. Be mindful of the cumulative effect of eating even moderate FODMAP foods.


Problem 2: Stress and Anxiety

Stress and anxiety can make IBS symptoms worse and make it seem as though the low FODMAP diet isn’t working. When you’re stressed, your gut becomes more sensitive, which can potentially lead to worsening symptoms.


Troubleshooting Tips:

  1. Practice stress-reduction techniques. Try to incorporate relaxation exercises, meditation, or yoga into your daily routine to manage stress and anxiety. Reducing stress can help improve the effectiveness of the low FODMAP diet.
  2. Consider Cognitive Behavioural Therapy. Cognitive behavioural therapy (CBT) is a type of therapy that looks at the connection between thoughts, feelings, and behaviours. It teaches you how to evaluate and modify your thoughts and behaviours to make them more helpful. A meta-analysis looking at the effects of CBT on IBS symptoms found that CBT effectively reduced IBS symptoms, improved quality of life, and improved psychological states.
  3. Try Gut-Directed Hypnotherapy. Gut-directed hypnotherapy (GDH) is a technique that uses relaxation and focus to communicate with your gut. It helps the mind and body work together to make your gut feel better without making any changes to your diet. It may help with pain, bloating, and other IBS symptoms, and research shows that it is just as effective as the low-FODMAP diet. However, it is not a quick fix and does not work for every person with IBS.


Problem 3: Overlooking Non-FODMAP Triggers

While FODMAPs are a common trigger for digestive symptoms, other factors can also make your symptoms worse. Some non-FODMAP IBS triggers include:

  • Caffeine
  • Alcohol
  • Fatty foods
  • Spicy foods
  • Carbonated drinks
  • Certain medications (such as antibiotics, NSAIDs, and some antidepressants)
  • Hormonal changes
  • Vigorous exercise


Troubleshooting Tips:

  1. Limit potential non-FODMAP triggers. Reduce or eliminate non-FODMAP trigger foods from your diet to see if it helps get your symptoms under control.
  2. Keep a food diary. Record your food intake and symptoms to help you identify patterns and potential triggers that may not be related to FODMAPs.
  3. Engage in moderate-intensity physical activity. Moderate exercise can have a beneficial effect on IBS symptoms for many people.


Problem 4: Unbalanced Gut Microbiota

The gut microbiota is the trillions of microbes that inhabit your gut. Studies show that IBS is associated with changes in the gut microbiota. Plus, the low-FODMAP diet may inadvertently impact your gut microbiota, which could hinder its effectiveness.


Troubleshooting Tips:

  1. Consult a registered dietitian: An IBS dietitian with experience teaching people about the low FODMAP diet can help you create a balanced meal plan that supports a healthy gut microbiota.
  2. Consider probiotics. Some strains of probiotics may be beneficial for people with IBS. It’s best to discuss the use of probiotics with your healthcare provider, as there are many different types available and not all of them have been shown to help with IBS.


Problem 5: You’re Not Getting Enough Fibre

One of the most common problems seen when a person is following the low FODMAP diet is not eating enough fibre. Fibre is essential for promoting bowel regularity and helping your gut microbiota thrive.


Troubleshooting Tips:

  1. Focus on low-FODMAP, high-fibre foods. You can maintain a healthy fibre intake on the low FODMAP diet by choosing foods that are both low in FODMAPs and rich in fibre. These include quinoa, oats, and chia seeds. Looking for more inspiration? Check out my blog post about low-FODMAP, high-fibre foods.
  2. Increase fibre gradually. If you’re new to the low-FODMAP diet or have been avoiding high-fibre foods, it’s important to gradually introduce higher-fibre foods into your diet so your digestive system has time to adapt. Start by incorporating small servings of low-FODMAP, high-fibre foods and gradually increase your portions as tolerated.
  3. Increase soluble fibre. Soluble fibre is easier to digest and may be better tolerated by people with IBS. Foods rich in soluble fibre include unripe bananas, potatoes, and oatmeal.


Problem 6: Other Medical Conditions

It’s important to ensure that other causes of digestive symptoms have been ruled out before beginning the low FODMAP diet. Conditions such as celiac disease, inflammatory bowel disease (IBD) and food sensitivities can mimic IBS symptoms and require different dietary and medical approaches.


Troubleshooting Tips:

  1. Seek medical evaluation. Consult with a healthcare provider to rule out other underlying conditions and to get appropriate testing and diagnosis.


Final Thoughts

The low-FODMAP diet can be a valuable tool to help you manage digestive symptoms. However, many factors can lead to the low-FODMAP diet not working for everyone or every situation. In fact, a study has shown that the low-FODMAP diet only works for around 70% of people. If you happen to fall into the group of people who don’t find relief from the low FODMAP diet, you may need to try other strategies.


If you’re not experiencing the expected relief from the low-FODMAP diet, try not to get discouraged. Troubleshoot possible reasons outlined by this blog post and consider working with a registered dietitian who can help tailor your dietary approach to your specific needs. Remember that individual responses to dietary changes can vary, and finding the right solution may require patience and persistence.


Low-FODMAP diet not working for you? Click here to book a free 15-minute call with Keren, a Monash FODMAP-trained dietitian. During the call, she will discuss your concerns and help determine if you’re a good fit for working together.

Get in touch with Keren and book a free 15-minute discovery call today!

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