Mistakes you are probably making on the low FODMAP diet

There is a HUGE amount of information out there on the internet about the low FODMAP diet. Some of it old, a lot of it inaccurate and even irrelevant.

Soooo, we’ve decided to give you some insight into the common issues our clients experience when they have tried to undertake the low FODMAP diet (and rechallenges) without the help of a dietitian (the horror!).

1. Missed & accumulated FODMAPs:

Even with lots of planning, it can still be easy to miss things like:

• choosing the wrong type of soy milk
• chewing gum
• hidden ingredients in processed foods and supplements
• having too much low FODMAP fruit
• ‘stacking’ of moderate FODMAP options
• spelt products , particularly spelt pasta

2. Being WAY too strict

Being too strict the low FODMAP diet (particularly if you don’t need to) is not a great idea because it can make the diet really challenging to follow. In addition, you may end up under-nourishing yourself AND at the same time, depriving your gut of lovely substances that are good for gut health.

We commonly see over-restriction of:

• ‘moderate’ FODMAPs
• products containing low amounts of wheat or lactose/dairy
• lactose – (not necessary in all people)
• all legumes – some are suitable in smaller portions

Not everyone needs to follow a strict version of the low FODMAP diet and may benefit from reducing just their major FODMAP triggers. We can help individuals determine the level of restriction required and make the process less burdensome.

3. Which brand is suitable?!?!?!

Having the knowledge of appropriate brands, where to buy these products and which products to be cautious of, can help with food purchasing.  

There are FODMAP certification programs and low FODMAP stickers on products that will help to identify low FODMAP products. However, it is important to keep in mind that there are many brands and products are still suitable even if they don’t have these stickers.

Some companies may not be aware of or just choose not to go through these certification programs.

4. Lack of understanding of how FODMAPs alter gut function

A dietitian may recommend changes to a client’s diet or supplements in addition to a reduced FODMAP diet depending on the IBS-subtype (i.e. whether they are diarrhoea or constipation prone) and the individual’s presentation.

For example, people with constipation-prone IBS (IBS-C) may benefit from actually including one of the FODMAPs, sorbitol, in their diet due to its laxative effect. It is possible that constipation may worsen if this, or other specific FODMAPs, are removed. Alternatively, a non fermentable fibre (i.e. not a FODMAP) supplement may be required.

It is important to keep in mind that if constipation worsens, other IBS symptoms may increase. As a result, having an understanding of the effect FODMAPs have on the gut is crucial, particularly if the response to the diet is less than expected.

5. Reduced nutrient intake

Any patient who has a restricted diet (such as other food intolerances, food allergies, vegetarian or vegan) needs support from a dietitian when undertaking low FODMAP diet to ensure adequate nutritional intake can be maintained.

If the individual has a current or previous eating disorder, it is particularly important to have dietitian involvement to help avoid over restriction of food.

6. Inappropriate trial for children

The low FODMAP diet can be difficult to follow with young children who often have strong food preferences or are fussy eaters. Toddlers often only need a relaxed version of the diet and dietitians can help individualise the diet trial so that it is realistic, achievable and nourishing as possible.

7. Staying on the diet long term

We see this ALL the time.

The low FODMAP diet should only be used for a short period of time (2-6 weeks) to determine whether these foods are affecting gut function.

Many people are unaware of the importance of ‘challenging’ the FODMAP groups once the elimination phase is finished.

So often we see people strictly following a low FODMAP diet for long periods of time. As a result, these individuals are reducing their intake of prebiotics* which are important for good gut health. Having a low intake of prebiotics can lead to a reduced response to the low FODMAP diet over time (i.e. becoming more sensitive) with deterioration of healthy gut bacteria.

Read more about this topic in our blog Low FODMAP not for life!’

*naturally occurring indigestible carbohydrates that feed the good bugs in our gut. You can also read a bit more about prebiotics here.

8. Trialling the wrong approach or limited response to the diet

We can help if the individual falls within the 25-30% where the response to the low FODMAP diet may be sub-optimal.
Dietitians can:

• explore the impact of other foods
• tweak the low FODMAP diet to achieve a better outcome or
• provide a pathway to other therapies or other health professionals if necessary

9. Trial not appropriate

IBS or Functional Gut Disorder (FGD) should only be suspected if a complete medical work-up has been performed. Removing wheat from the diet can also delay the diagnosis of coeliac disease or make excluding coeliac disease challenging as many people are reluctant to gluten-load prior to testing, particularly if they perceive wheat to be trigger of symptoms.

10. Incorrectly rechallenging

Many people still challenge FODMAPs incorrectly. This can result in uncertainty around what foods and / or amounts of foods they can tolerate. In turn, this can often lead to over-restriction. It is also possible that the total FODMAP load is the issue. In this instance, challenging of individual FODMAP groups may not induce any symptoms.

We can help with any of the above topics raised in this article.
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