Talk to experts before going on low FODMAP diet
lead to changes in bowel motions.
Given how common IBS is – about one in five New Zealand women have IBS – and the impact that it can have on quality of life, it’s no surprise that the low Fodmap diet has become hugely popular.
Food companies are now making low Fodmap products, you can find low Fodmap cookbooks in book shops, and blogs, and websites and apps provide an enormous amount of information to help people follow the diet.
While this can be extremely valuable for those on the diet, it also means that people can now potentially try this on their own without the support of a nutrition professional, and in some cases this can have unintended consequences.
Because some Fodmaps have prebiotic effects, namely GOS and fructans, a low Fodmap diet restricts the intake of prebiotic fibres. Prebiotics are the food for our gut bacteria. A prebiotic-rich diet is considered beneficial, and there are concerns that the restriction and/or elimination of these may be detrimental to longterm gut health.
Before going down the low Fodmap path, it’s important to see your doctor to rule out any other conditions affecting the gut. This is something that a qualified nutrition professional will always check before starting a client on a low Fodmap diet, so people who begin the diet on their own may miss this crucial step.
The low Fodmap diet can be quite restrictive and many nutritious foods are high in Fodmaps, so if it is followed longterm without professional guidance, you may also be at risk of nutritional deficiencies.
The low Fodmap diet is not a no Fodmap diet. Nor is it a forever diet – it is a tool intended to identify the foods triggering your symptoms. As the diet isn’t curative (it is for symptom management only) and work must continue to be done on the gut and digestion to help improve its function.
The Fodmap dietary management of IBS consists of stages, with the first stage being the low Fodmap diet. This stage, in which you eliminate high Fodmap foods, is only intended to last for up to six weeks. From here, you begin the challenge/ reintroduction phase, where you systematically reintroduce one Fodmap at a time to assess your tolerance.
Not everyone reacts to the same Fodmaps (for example, you may only react to one or two of the Fodmaps) or to the same extent, so you don’t necessarily need to eat in a way that is completely low Fodmap to manage your symptoms.
At the end of this process you should understand which Fodmaps you react to and the doses of these that you can tolerate. You can then personalise the diet to manage your symptoms, without unnecessarily restricting the foods you can eat.
Symptoms are only experienced once your overall load for a particular Fodmap exceeds your personal tolerance threshold, so you only need to restrict Fodmaps to the extent required to remain below this.
For example, in my experience, some people only need to avoid onion, garlic and apples for adequate symptom relief.
If you are interested in trying the low Fodmap diet, I can’t encourage you enough to seek guidance from a qualified nutrition professional with experience in this approach.
Dr Libby is a nutritional biochemist, best-selling author and speaker. The advice contained in this column is not intended to be a substitute for direct, personalised advice from a health professional. See Dr Libby live during her upcoming ‘What Am I Supposed To Eat?’ tour throughout New Zealand. For more information and to purchase tickets, visit drlibby.com