What is the low FODMAP diet?

How to Start a Low Fodmap Diet Plan… (And When You Would Want To)

Do you suffer from bloating, constipation, abdominal pain and other digestive issues after eating certain foods?

Are your digestive issues affecting your quality of life?

If so, going on a low FODMAP diet plan could resolve many of your symptoms.

As a Naturopath who has seen many people with food sensitivities, I can attest to the fact that starting on a low FODMAP diet plan could dramatically improve your quality of life.

In this article, you will learn what a low FODMAP diet is, how FODMAPs affect your gut, who can benefit from a low FODMAP diet, how it works, and important limitations about the diet that you should be aware of.

What is the low FODMAP diet?

What is the low FODMAP diet?

If you have digestive issues particularly IBS, you may have heard about the low FODMAP diet!

What exactly is it?

It is a diet that restricts your consumption of FODMAPs. What is a FODMAP? A  FODMAP is actually an acronym for carbohydrates that we don’t absorb well and that are found in common foods. It stands for:

  • Fermentable-Substances that are broken down by bacteria in your gut causing you to produce intestinal gas.
  • Oligosaccharides-Substances made of chains of sugars. These substances may give you a stomach ache. They are found in foods such as wheat, rye, onions, garlic, legumes and pulses.
  • Disaccharides- Substances made of two sugars. One such disaccharide is lactose. If you lack the enzyme lactase, you will not be able to properly digest lactose and may have digestive problems after eating foods that contain lactase such as milk, soft cheeses and yoghurt.
  • Monosaccharides- Substances made of one sugar e.g. fructose and glucose. We absorb fructose well if there is enough glucose. However, if you consume high-fructose containing foods which are also low in glucose such as honey or apples, you may not be able to absorb fructose well.
  • Polyols- These are sugar alcohols and include substances such as sorbitol and mannitol which you may recognize as artificial sweeteners.

What is the low FODMAP diet?

Here is a short video that describes FODMAPs and common sources:

Effects of FODMAPs on Your Gut

How do FODMAPs lead to digestive problems?

As I mentioned earlier, FODMAPs are not well absorbed. In fact, FODMAPs draw fluid into your intestines. The bacteria in your colon also ferment FODMAPs quickly which causes you to produce gases such as hydrogen, carbon dioxide and methane.

The extra fluid and gas cause your intestines to expand which causes you to feel bloated and experience abdominal pain. They also cause peristalsis (the relaxing and contraction of your intestinal muscles) which may cause you to have diarrhoea, or in some cases, constipation.

You may be surprised to know that everyone experiences these symptoms – it is actually quite normal. However, if you have IBS, you are more susceptible to these symptoms. Why?

Your intestinal muscles respond abnormally to the expansion caused by FODMAPS and your gut is extra sensitive to changes in your intestines and too nervous system and immune system signals in your digestive system.

Here is a short video that describes how FODMAPs trigger digestive problems.

Why would someone follow a low FODMAP diet plan?

If you suffer from digestive problems, a low FODMAP diet plan may be for you. In my experience as a Naturopath, I have seen how effective a low FODMAP diet can be in relieving symptoms of gas, bloating, diarrhoea and other digestive problems and how individuals can feel free to live their lives again.

The low FODMAP diet was developed for people with IBS, however, research has shown that a low FODMAP diet plan can be helpful for a variety of conditions including:

  • Irritable Bowel Syndrome (IBS)
  • Small Intestinal Bacterial Overgrowth (SIBO)
  • Functional Gastrointestinal Disorder (FGID)
  • Auto-immune diseases such as eczema, rheumatoid arthritis, and multiple sclerosis
  • Inflammatory Bowel Disease (IBD)
  • Frequent migraines triggered by certain meals
  • Fibromyalgia
  • Non-coeliac gluten sensitivity
  • Ileostomy
  • Gastroesophageal reflux disease (GERD)

The low FODMAP diet may also be helpful if you suffer from diverticulitis and exercise-induced gastrointestinal symptoms, although more research is needed.

Depositphotos 29295571 original

Not sure whether you may benefit from a low FODMAP diet?

If you answer “Yes” to the following questions, you may benefit from this diet:

  • Do you experience digestive problems such as excessive gas, bloating, diarrhoea and/or constipation and pain in your abdomen?
  • Have you seen a doctor and been diagnosed with IBS or other conditions that could benefit from a low FODMAP diet?
  • Has your healthcare professional recommended a low FODMAP diet?
  • Have you received a negative screen for Coeliac Disease?
  • Have dietary lifestyle modifications such as eating regular meals, managing your stress, and getting enough fiber, fluids and exercise been unhelpful in managing your symptoms?
  • Are you at a point physically, mentally and emotionally where you can follow a strict dietary change without damaging your health?
  • Are you able and willing to try a dietary experiment?

How to start a low FODMAP Diet Plan

The low FODMAP diet involves 3 phases:

  1. Phase 1: Low FODMAP diet phase or elimination phase

During this phase, I will place you on a strict diet that eliminates food that are high in FODMAPs and replace them with foods that are low in FODMAPs. Replacing high FODMAP foods with low FODMAP foods is important as you need something to eat, right?

I will also get you to track the foods you eat and the symptoms you experience during this phase. About 75% of clients who have IBS should notice improvements in their symptoms.

Many of my IBS clients experience significant improvements in their symptoms 1 to 2 weeks after starting the diet, but don’t worry if your symptoms don’t improve at the 1 or 2-week mark! Some of my clients need 3 to 4 weeks before they notice improvements in their health. The elimination phase lasts 2-6 weeks.

  1. Phase 2: Re-challenge phase

During this phase, I will reintroduce high FODMAP foods one at a time every few days back into your diet. This will help you figure out the type and quantity of high FODMAP foods you can tolerate. I will also get you to track your symptoms during this phase.

There is no set standard for re-introducing high FODMAPs to your diet. Your health care professional can tailor the introduced foods according to your symptoms, food likes/dislikes, or foods that you crave the most from your diet. Or, your healthcare professional may start with FODMAPs which tend to cause the least amount of digestive problems in most individuals; polyols. This phase lasts about 6-8 weeks.

  1. Adapted diet phase

During this phase, I will interpret your results and place you on a diet that includes the high FODMAP foods that you can tolerate and the amounts and frequency you can tolerate them at. From experience, I have found that many of my clients are able to add many high FODMAP foods back to their diet, but may have to restrict how much and how often they are able to eat them.

Here is a short video that explains the low FODMAP diet process:

What is the low FODMAP diet?

Key Mistakes People Make on the low FODMAP diet

As you can see, the low FODMAP diet process is a very involved process. Here are pitfalls to avoid to ensure that you stay on track with your diet and your health.

  1. Not getting a thorough assessment before starting a low FODMAP diet.

You should get a thorough assessment from a FODMAP diet trained health professional before starting the diet. When I assess you I will let you know if you are a good candidate for the diet.

For instance, if you have IBS and are under a lot of stress, starting the low FODMAP period may not be appropriate for you as stress can cause flare-ups of your IBS. Likewise, if you are at risk of eating disorders, the low FODMAP diet may not be for you as it may feed into your restrictive eating tendencies.

Also, if you live in a nursing home or long-term care residence, you may not be a good candidate for the diet as the diet requires that you have control over the purchasing and preparation of your food to ensure the foods are low in FODMAPs for the elimination phase.

  1. Changing too many of your treatment components all at the same time  

It is important that you do not change your medications and supplements at the same time as when you change your diet. Otherwise, we will not be able to figure out which components of your diet are working for you. Speak with all of your health care providers about the start date of your low FODMAP diet; they may be able to delay prescribing new medications or supplements until after your low FODMAP diet.      

  1. Restricting your diet too much

When following a low FODMAP diet, it is important to make sure you are not restricting your diet too much.

A nutrient you may skimp on when consuming a low FODMAP diet is fibre. Yes, many high fibre foods contain FODMAPs, but there are a number of low FODMAP foods that contain fibre as well.

These include some low FODMAP fruits, vegetables, grains and legumes. Your health care professional (myself included) can ensure that your low FODMAP diet is well-balanced. I can also give you recipe ideas and how to understand food labels and ingredient lists.

  1. Using the wrong resources

Your low FODMAP diet is only as good as the resources that you follow. If you search the internet, you will find that there are many FODMAP lists available; however many of these lists are not accurate or are not up to date.  Two resources you can count on are the Monash University Low FOPMAP diet App, and the Monash University Low FODMAP Diet book , which was developed and is regularly updated by the University which created the diet.

Sample Meal Plan

Curious as to what a sample low FODMAP meal plan looks like?

Here is a one-day dietitian designed meal plan from Diet vs Disease.

One Day Meal Plan

BreakfastLow FODMAP Blueberry Smoothie. Prepare a huge batch so you do not have to make it from scratch every morning.

Lunch: Fresh Spring (Rice-Paper) Rolls. Choose up to 3 vegetables (from this list) and toss in some protein if you want. Exclude the avocado and scallions.

Dinner: Maple Garlic Glazed Salmon + low FODMAP vegetables (from the link above) + 1 cup cooked brown rice (good for fiber).

Snack 1:  One big handful of macadamias, Brazil nuts or walnuts (40g maximum). These are good for fiber and nutrients.

Snack 2: Certified low FODMAP Dark Chocolate, Nuts and Sea Salt Snack Bar.

Here is another good educational resource reviewed by a Monash University professional that you may find helpful.

What is the low FODMAP diet?

Is a Low FODMAP diet the best diet for IBS?

Now before I answer the question, let’s talk a little bit about IBS (Irritable Bowel Syndrome).

IBS affects 9-23% of the world’s population. Symptoms of IBS include constipation, diarrhoea, abdominal pain, feeling like you need to go to the bathroom, bloating and even non-digestive problems such as tiredness and backaches. Food is a common trigger for IBS, but stress and hormones trigger IBS as well. If you are female, you may notice more flare-ups of your symptoms around your menstrual periods.

Now back to the question– The answer is “Yes”. The standard diet for IBS was/is one that recommended/recommends among other things limiting your alcohol, caffeine, fizzy drink, spicy food and fatty food intake. It also recommended/recommends that you drink 1.5-3 L of fluid per day. Now imagine being from a culture where spicy foods are the norm and having to limit these foods? Or if you are a caffeinated coffee lover, imagine having to restrict your cuppa coffee? Not fun.

Now the good thing about the low FODMAP diet is that you do not necessarily need to restrict these foods. Furthermore, research has shown that the low FODMAP diet may improve IBS symptoms better than other diets.  What’s more, high-quality studies have shown that the low FODMAP diet improves symptoms in more than 70% of IBS patients.

Now, what about the other 30% of IBS patients for whom the low FODMAP diet does not work?

There are other non-diet related therapies that may help you. Mild physical activity may help reduce your IBS symptoms and reduce bloating and constipation. Do you like yoga? Yoga has also been shown to reduce IBS symptoms. Now before you lace up your shoes, be careful not to overdo it! Intense physical activity such as running may stress your intestines and cause “runner’s trots aka runner’s diarrhoea”.

Acupuncture has also been shown to relieve symptoms of IBS. A 2009 study found that of the 230 patients who had IBS, those who were given acupuncture had less IBS symptoms than those who did not. What’s more- those who received simulated acupuncture also had less IBS symptoms than those who received no acupuncture (real or simulated). Great news if you hate needles!

Hypnotherapy (hypnosis) may also help relieve IBS symptoms. Many studies have shown a link between hypnotherapy and less IBS symptoms.

Does a Low FODMAP diet help with SIBO treatment?

Before I answer the question, let’s talk briefly about SIBO (Small intestinal bacterial overgrowth). SIBO occurs when your small intestines are overrun by bacteria. If you have SIBO, you will experience many of the symptoms as those with IBS. You will have abdominal pain, bloating, gas and diarrhoea. A number of people with IBS also have SIBO.

Now back to the question– Research has shown that a low FODMAP diet may also be helpful if you have SIBO. However, when you are on a low FODMAP diet, you are simply starving the bacteria in your small intestines. If you stay on this diet long term, you will also end up starving the bacteria in your large intestine that are important for maintaining good health.

The Downsides of a low FODMAP diet plan and why it isn’t a long-term solution

As great as the low FODMAP diet is at relieving symptoms, it is not a long-term solution. FODMAPs have their benefits- they feed the good bacteria in your large intestines, in particular, the bacteria responsible for producing butyrate.

Butyrate helps you maintain a healthy gut. Butyrate may also be helpful if you suffer from ulcerative colitis; it may reduce your risk of colon cancer or keep you in remission. For these reasons, you will want to progress from a low FODMAP diet to an adapted high FODMAP diet.

It is for these reasons that I like to use gut bacteria testing, aka gut microbiome testing, with my clients. This allows me to see what is really happening on a deeper level, within their gut, and focus on bringing their bacteria back into balance.


The low FODMAP diet is a diet that limits the amount of FODMAPs, poorly absorbed carbohydrates, that you consume. High FODMAP foods can lead to digestive problems such as gas, abdominal pain, constipation, and diarrhoea.

Everyone experiences these digestive problems to some degree when they eat foods high in FODMAPs; however, if you have IBS, you experience these symptoms more. Research has shown that a low FODMAP diet may help you if you have IBS or a number of other digestive problems.

A low FODMAP diet plan has 3 phases: the elimination phase (aka low FODMAP diet phase), the re-challenge phase, and the adapted diet phase.

There a number of key mistakes that people make on the low FODMAP diet including restricting their diets too much and using the wrong resources. A healthcare provider trained in the low FODMAP diet can help you avoid some of these mistakes. The low FODMAP diet is the best diet for those with IBS and is also helpful for those with SIBO.

As helpful as the low FODMAP diet is for reducing the symptoms of IBS, it is not a long-term solution as it reduces the amount of health-promoting bacteria in your large intestines. As a result, you will want to progress from a low FODMAP diet to an adapted high FODMAP diet that makes you comfortable.

What is the low FODMAP diet?


Did you enjoy this article? I sure enjoyed compiling it!

Having seen how implementing a low FODMAP diet plan has helped many of the clients I have worked with, I felt that sharing this information with you would give you the know-how to determine whether this diet may be right for you. I also wanted to give you hope that you can experience a better quality of life.

I hope that you will take the necessary steps to take control of your health- after all, health is wealth!

Let us know what you think in the comments and feel free to share this article with your friends!

How to start a low FODMAP diet plan

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