Can FODMAP Tolerance Change?

So you’ve completed the elimination and reintroduction phase of the low FODMAP diet and have a pretty good idea of what you can tolerate and what you can’t. But what my patients really want to know is: Will I be stuck eating this exact diet, day in and day out, for the rest of my life? Today, we’re going to be talking about how FODMAP tolerance can change, so that you can have the most liberalized diet possible!

Why does FODMAP tolerance change?

To understand how to liberalize your diet, first, we need to understand why changes to tolerance may occur. Some of the most common reasons are:

1. Stress – Stress can greatly influence your gut symptoms. For example, many of my patients find when they’re on holiday, they can eat a lot more FODMAP’s than when they’re in the daily grind of life. When stress goes up, they notice their FODMAP tolerance go down.
2. Interfering with your body clock – Your gut functions on your body’s circadian rhythm or internal body clock. Had a late night or experienced a time change? This may impact your gut symptoms and ability to tolerate more FODMAPs.
3. Medication changes – medication can impact your digestion. If you’ve had a recent medication change, prescription or not, this may help, or hinder your gut symptoms. Your dietitian, pharmacist, or doctor can review this with you.
4. A recent illness – not only does being sick suck – being sick, especially with a gut bug or with an illness requiring antibiotics, can exacerbate your gut symptoms – even when the illness has come and gone.
5. Hormones – changes in our hormones and menstrual cycle can influence your ability to tolerate FODMAPs.
6. Changes in movement, routine, or eating patterns – even if you don’t change WHAT you eat, changing your eating environment (i.e., in a rush, or having longer breaks between meals) can influence your FODMAP tolerance.

While this list isn’t all-inclusive, it encompasses the most common reasons we see in practice for changes in FODMAP tolerance. Some of them are manageable, whereas others, (like illness) we have to ride out. However, having a greater understanding and being patient with changes in gut symptoms is key. I see many patients jump into restricting further when their gut symptoms worsen, rather than ‘riding the wave’ and seeing how it settles out. Understanding that IBS is a transient condition that can change over time often allows for patients feeling a little less stressed about changes in their symptoms and FODMAP tolerance.

How to improve FODMAP tolerance long-term

Now that we know how FODMAP tolerance may change or worsen, now we can focus on how to improve tolerance long-term. Research shows that many interventions that aren’t food-related are AS impactful as the low FODMAP diet, which is why we suggest a four pillar approach. While there isn’t research yet to show how impactful combining approaches is, it would make sense that, if we tackled IBS from a multi-pronged approach, we would figure out what a) works for each patient and b) have a ‘toolkit’ of management strategies. We encourage patients to incorporate lifestyle interventions shown to have benefit in IBS including (but not limited to):

• Exercise
• Mindfulness, stress management, and therapy
• Sleep hygiene
• Medication management

Again, to learn more about these approaches be sure to check out our practices five-part post on the four-pillar approach so that you can improve your IBS symptoms long term!