Welcome to your go-to guide for the low FODMAP diet. This mega-guide will teach you the fundamentals of the low FODMAP diet and get you started on the first phase, also known as the low FODMAP elimination phase.
This article will cover:
- Safety tips: what to do before you start
- Who should use the low FODMAP diet?
- What is the low FODMAP diet? Overview of the three phases
- What are FODMAPs?
- How do FODMAPs trigger symptoms?
- Tips for starting the low FODMAP diet
- Making The Diet Easy: Your FODMAP Guide
- Are A Little Bit Yummy recipes suitable for the first phase?
- Common FODMAP diet questions
- When do you start the reintroduction phase?
Safety Tip: Before you get started
Before starting the low FODMAP diet, you must talk to your doctor to check if the diet is right for you.
Your doctor needs to rule out that your gut symptoms are not caused by other conditions like coeliac (celiac) disease, inflammatory bowel disease, Crohn’s disease, or cancer (1 2). Unlike Irritable Bowel Syndrome (IBS), these medical conditions cause damage to your gut, and need different treatment plans. Once you are on the low FODMAP diet, testing for some of these medical conditions can become more challenging.
Who should use the low FODMAP diet?
The low FODMAP diet is predominantly used to help people with IBS reduce their gut symptoms and identify their food triggers. Research shows that the low FODMAP diet can help up to 75% of people with IBS improve their symptom management and reduce bloating, distension, excess gas and altered bowel movements (diarrhoea and constipation) (3).
What is the low FODMAP diet?
Essentially the low FODMAP diet is a medical diet that can help you manage your gut symptoms and learn about your food triggers. It’s best to think of this diet as a learning journey that has three phases:
1. Low FODMAP Phase or Elimination Phase:
The goal is to reduce the number of high FODMAP foods you eat and focus on eating low FODMAP foods so you can see if high FODMAPs are triggering your gut symptoms. This phase only lasts for 2 to 6 weeks.
2. FODMAP Reintroduction Phase:
In this phase, you bring back in specific high FODMAP foods to see which of the FODMAP groups might be your food triggers. This is sometimes also called the Challenge phase
3. Adapted FODMAP Diet or Personalisation Phase:
You relax your strict low FODMAP diet by bringing back the FODMAP groups you tolerated well during your reintroduction phase. This process helps you improve the variety of foods and social food freedom you can have while keeping your symptoms settled.
The low FODMAP phase is not a lifetime way of eating and should only be followed strictly for 2 to 6 weeks before moving into the FODMAP reintroduction phase (4,5). In addition, this medical diet can be complex to navigate, so it should be followed with the help of guided support and an experienced FODMAP trained dietitian.
What are FODMAPs?
Now we are getting into the nitty-gritty of the diet. If you are sitting there thinking FOD-what? you aren’t the only one. In super simple terms, FODMAPs are fermentable short-chain carbohydrates, aka naturally occurring sugars (don’t worry, the diet isn’t sugar free). FODMAPs occur in a wide range of fruit, vegetables, cereals, grains, dairy products, legumes and pulses. These are all healthy foods that we should be eating right? Yes! So let us show you how you can do this without setting off your symptoms.
Let’s break down the FODMAP acronym:
We kind of start backwards here – in our bowel (or large intestine). FODMAP carbohydrates enter our large intestine which provides extra food for our gut bacteria. As they eat the FODMAP carbohydrates, our gut bacteria break them down. This process is called fermentation and produces gas (hydrogen, methane and carbon dioxide) (5 6).
We can break this complex-sounding FODMAP group into two subgroups: fructans and galactans. Fructans (fructo-oligosaccharides or FOS) are found in foods like onion, garlic, wheat, rye, barley and dried fruit. Galactans (galacto-oligosaccharides or GOS) can be found in foods like silken tofu, pistachios, cashews, legumes and pulses (5 6).
Have you ever wondered why beans make people fart? This excess gas happens because humans weren’t born with the enzymes needed to digest oligosaccharides, so they will make everyone gassy but only trigger gut-based symptoms in some people with sensitive guts (2 6).
The only disaccharide you need to worry about is lactose which is found in some products made from cow, sheep or goat’s milk. Lactose contains two sugar units that need to be ‘unzipped’ using an enzyme called lactase before our bodies can absorb it. If your gut lacks lactase enzymes, then you will struggle to process high lactose products and the lactose might trigger symptoms.
Lactose is found in milk, yoghurt and products like sour cream or cream cheese (5 6). The good news is that hard cheeses, lactose free milk or yoghurt, and butter are all okay when you are on the low FODMAP diet.
Here we are talking about excess fructose – which is when there is more fructose than glucose in a food. Our bodies need an equal amount of glucose in the food to help the fructose be absorbed in the small intestine (2 6). When you are on the low FODMAP diet, we only need to restrict foods containing excess fructose like apples, pears, mango, honey, asparagus, and high fructose corn syrup.
Polyols are sugar alcohols, but they won’t make you drunk. This FODMAP group is broken down into two subgroups: mannitol and sorbitol. These sugar alcohols are found in a wide range of fruit (like apples, pears, stone fruit, lychee) and vegetables (mushrooms, cauliflower, sweet potato). They can also be artificially made and used as low-calorie artificial sweeteners. Make sure you check products like protein powders, chewing gum, diabetic candy and low sugar/sugar free products for these sweeteners.
The reason polyols can be problematic for some people is because they are only partially absorbed in our small intestines. The remaining polyols continue to our large intestine, where they are fermented by our gut bacteria (2 6).
How do FODMAPs trigger symptoms?
So you now know what FODMAPs are, but how do they trigger symptoms?
When you eat FODMAPs they travel through your stomach and into your small intestine. Here, they are poorly absorbed and draw water into our bowel. Next, the FODMAPs travel to our large intestine, where our gut bacteria ferment them as they break down the food. This fermentation can create gas that can trigger gut-based symptoms like excess wind, bloating, distension, diarrhoea, and constipation when combined with the excess water.
How long should you stay on a low FODMAP diet?
A strict low FODMAP diet is not for life. The diet’s first phase, where you reduce your FODMAP intake, should only last for 2 to 6 weeks. Then, once you see if the low FODMAP diet helps significantly reduce your gut symptoms, it’s time to move on to the FODMAP reintroduction phase.
High FODMAP foods can be important for long-term gut health, so it’s important to bring some high FODMAP foods that don’t trigger symptoms back into your diet.
Tips To Help Get You Started
If you’ve decided it’s time to start transitioning onto the low FODMAP diet. Just remember you don’t have to do this all at once; we often find people do better if they transition onto the diet over a couple of weeks.
Here are some quick tips to get you started:
1. Keep a record of your symptoms. Write down what your symptoms have been like over the past week. These symptom notes will help you track your progress and see if the diet is working. Our online symptom tracker can also make this process easy when you join the FODMAP Wellness Club.
2. Find an up-to-date high FODMAP and low FODMAP food list. Online lists and free FODMAP apps go out of date every few months, so we recommend using the Monash University FODMAP Diet App or our food lists in our FODMAP Made Easy programme.
3. Write down what you plan to eat over the next four days and start by swapping out high FODMAP foods you eat regularly for low FODMAP options using a food list.
4. Check your processed foods for sneaky high FODMAP ingredients. This label reading guide can help.
5. Create a low FODMAP meal plan. It would help if you had a couple of breakfast ideas, 4 or 5 snack ideas (including a treat), 2 to 3 easy lunch ideas and 5 low FODMAP dinner ideas to get you started. We’ve got over 850+ low FODMAP recipes and meal planning tools to help get you started in our FODMAP Made Easy programme.
Your FODMAP Guide
It’s okay if moving onto the low FODMAP diet feels hard. We are here to help make things easy. Our FODMAP Made Easy Programme has EVERYTHING you need to settle your symptoms and identify your trigger foods.
We’ll guide you through the three phases of the low FODMAP diet with online courses, delicious recipes, helpful handouts, meal planning tools, weekly support emails and dietitian-led classes. You can also message our FODMAP team for extra help.
When it’s time to find your food triggers we’ll help you manage your anxiety and give you step-by-step instructions on how to reintroduce each of the FODMAP groups.
Are A Little Bit Yummy recipes suitable for the first phase?
Yes, they are! Our recipes are made using the low FODMAP guidelines from Monash University (the lead researchers of the low FODMAP diet). Each recipe is also checked by a FODMAP trained registered dietitian so you can eat with confidence. These checks mean you can use our recipes during the FODMAP elimination phase.
Are portion sizes important in the low FODMAP diet?
Sure are! Foods often have low FODMAP, moderate FODMAP and high FODMAP portion sizes, so understanding portion sizes can help you reduce your FODMAP load faster. We talk about portion sizes more here.
Is the low FODMAP diet gluten free?
Can you eat dairy on the low FODMAP diet?
You can enjoy lots of low lactose or lactose free dairy products on the low FODMAP diet like hard cheeses, lactose free milk or yoghurt, small amounts of sour cream or cream cheese. You can find out more here.
Do you need to restart the low FODMAP diet if you have a high FODMAP meal?
No, you don’t. However, you need to make sure this isn’t happening all the time; otherwise, you won’t know if the diet is working. Read more about this topic here.
Is the low FODMAP diet sugar free?
How do you deal with constipation on the diet?
The low FODMAP diet can often help reduce bloating and cramps that come with constipation. However, the low FODMAP diet often needs to be combined with other food and lifestyle strategies to achieve better results. We have a Managing Constipation Masterclass in our FODMAP Wellness Club that can help. If you become constipated after starting the low FODMAP diet, you might need to increase the amount of low FODMAP fibre-rich foods and water in your diet (2).
Are alcohol & caffeine allowed during the elimination phase?
There are low FODMAP alcohol and coffee options. However, while on the low FODMAP elimination phase, it is often recommended that you limit your consumption of alcohol and caffeine (1 2). These can be gut irritants and sometimes make gut symptoms worse (1 2). You can test your tolerance to alcohol and caffeine in the reintroduction phase of the low FODMAP diet.
When do you reintroduce high FODMAP foods?
You can start the reintroduction phase after 2 to 6 weeks on the low FODMAP diet (4 5). During this time, we want to see if reducing the number of high FODMAP foods you are eating has a significant positive impact on your gut symptoms. Of course, we don’t expect your gut to be perfect, but we hope that the low FODMAP diet helps you significantly reduce bloating, excess wind, and altered bowel movements. If you need help troubleshooting your gut symptoms, join the FODMAP Made Easy programme and our team can help.
As you can see the low FODMAP diet is a complex medical diet designed to help people with IBS manage their symptoms. We’re here to make the low FODMAP diet easy with our low FODMAP recipes, free blog articles and FODMAP Made Easy programme. Let us know in the comments below what you need help with as you start the FODMAP elimination phase.
1. BPACnz. Irritable bowel syndrome in adults: Not just a gut feeling. Best Practice Journal. 2014: Issue 58. 14-25. Retrieved from http://www.bpac.org.nz/BPJ/2014/February/ibs.aspx
2. Monash University App. About Section & Food Guide. The Monash University Low FODMAP Diet App. 2014: Edition 4. Date retrieved: 2015-03-05. Retrieved from :http://www.med.monash.edu/cecs/gastro/fodmap/iphone-app.html. Accessed: 2015-03-05. (Archived by WebCite® at http://www.webcitation.org/6Wog73c8B)
3. Nanyakkara, W., Skidmore, P., O’Brien, L., Wilkinson, T., Gearry, R. Efficacy of the low FODMAP diet for treating irritable bowel syndrome. Clinical and Experimental Gastroenterology. 2016-06-17. Doi: 10.2147/CEG.S8798
4. Williams, M. The Low FODMAP Diet for Irritable Bowel Syndrome. Journal for Health Care Professionals. 2014. Retrieved from:http://www.drschaer-institute.com/smartedit/documents/download/dsif_02_2014_us_the_low_fodmap_diet_4.pdf. Retrieved on: 2015-03-09. (Archived by WebCite® at http://www.webcitation.org/6WuTYoHgd)
5. Monash University. Frequently Asked Questions. Monash University Low FODMAP Website. 2015. Retrieved from:http://www.med.monash.edu/cecs/gastro/fodmap/diet-and-ibs.html#5. Retrieved on: 2015-03-09. (Archived by WebCite® at http://www.webcitation.org/6WuTAniFE)
6. Mansueto, P., Seidita, A., D’Alcamo, A., Carroccio, A. Role of FODMAPs in Patients with Irritable Bowel Syndrome: A Review. Nutrition in Clinical Practice Journal. 2015-02-18. DOI: 10.1177/0884533615569886. Retrieved from http://ncp.sagepub.com/content/early/2015/02/17/0884533615569886