Starting the low fodmap diet can feel like diving into a whole new world of confusing portion sizes, traffic light systems and strange acronyms. Downloading the Monash Fodmap App is a great first step! But many people are left scratching their heads over what foods they can eat, how much is too much, and how the traffic light system really works. And upon reading that a 4 gram slither of pear is low fodmap, you start to worry about what on earth you CAN eat on this diet!

Let’s clear up the confusion and get you on the right track to managing your gut health with confidence! Here are the top 10 frequently asked questions about the App.

ps. This blog is for you if you already know what a fodmap is but would like to know more about how to use and interpret the cut-off thresholds specified in the App. If you haven’t gotten your head around fodmaps yet or simply need a refresher before we dive into the App, visit our introductory blog here.

#2 How are the low fodmap cut-offs determined?

The guidelines for what makes a food low fodmap were created by looking at how much fodmaps are in different foods and how much of those foods people typically eat in one meal. Researchers used clinical experience to figure out which foods commonly cause IBS symptoms and which are generally well-tolerated. Based on this, they set specific cut-off points for each fodmap - meaning how much of an individual food is likely to trigger symptoms in people with IBS. They’ve tested these cut-offs in repeated clinical studies.

As a general rule, keeping your fodmap intake under 0.5 grams (not counting lactose) per meal is safe for most people with IBS.

#5 For foods with just a green light (but no amber or red lights) why is there still a portion size listed on the Monash low fodmap App?

Have a look at the entry for white potatoes. There’s a large green traffic light – indicating that potatoes are low in fodmaps at a typical serving size. But there are no amber or red lights recorded under potatoes. This means that you do not need to limit yourself to 75g. In the fine print, you’ll find that there’s more information about the recommended serving suggestion.

For example, potatoes have no fodmaps detected up to a serving size of 500g. However, the App refers to nutritional guidelines to remind users of the recommendation of 5 veg and 2 fruits per day. This has nothing to do with the fodmap content of potatoes and more to do with eating a balanced diet. In another example, the App says that 19g or 1 tablespoon of butter is low fodmap but no amber or red cut-offs are listed. This implies that butter’s low fodmap rating is low but in the fine-print, the App adds more information about the effect of high fat foods on gut motility and symptoms. Given this extra information in the footnotes relates to nutritional guidelines NOT fodmap content, feel free to ignore it. Or look to the Fodmap Friendly App which gives additional information about upper limits.

#7 This product CLAIMS that it’s low fodmap and is even certified low fodmap but it includes a high fodmap ingredient. Is it safe to eat?

If the product is displaying the blue Monash University fodmap certification symbol or the green Fodmap Friendly fodmap certification symbol, rest assured that it has been tested for fodmap content at the recommended serving size. And once you become a label detective, you’ll be able to determine yourself if a product is uncertified but low fodmap by ingredient. If not, post a pic in our Friendly Fodmappers Facebook group and the brains-trust will help!

#9 If there’s a gap between the green serving size and the amber serving size, can I eat MORE than the green serving size but less than the amber serving size?

Good question! Diet cola is a good example. The standard serving size is 250ml (1 cup) - which is a regular can of soft drink. The large traffic light is red because it contains high amounts of fructans at one can. However, companies like Coca Cola then released a 200ml mini can. The App lists the green light serving size for cola as 162g and the amber serving size as 204g but a mini can is 200ml. Because this new serving size is between the green and the amber, then it would probably be low in fodmaps and OK to drink. But do check your own individual tolerance thresholds. Sadly, no amount of soft drink works for me.

#10 Why does the FODMAP level of some foods change in the app?

You might notice that the fodmap level of some foods changes over time in the App. This happens because Monash University continuously tests foods in their lab to make sure the information is as accurate as possible. Sometimes, newer testing methods or updated research shows different fodmap levels than what was originally found.

These updates are (mostly) a good thing! They ensure the App reflects the most current and accurate data, helping you make the best choices for your gut health. However, it can often be disappointing when the serving size of one of your favourite foods (strawberries) is reduced. If the green light serving size of a particular food is reduced but you’ve been tolerating the previous serving size – don’t panic! This just means that your individual threshold for this food is higher than that listed. Woot!

Making the low fodmap diet easier for you

Starting the fodmap diet can be overwhelming. The App definitely helps and is still a resource that I check (almost) daily. Once you’ve wrapped your head around the traffic light system, you’re half way there! Hope this blog has helped. Please send any questions to flora@noisyguts.net