If you’ve ever experienced digestive problems (in other words, if you’re a human being), then you know how uncomfortable they are both physically and socially. Now, imagine if you had to deal with digestive problems multiple times a week, every week. When other conditions that could cause these issues have been ruled out, a doctor might diagnose you with irritable bowel syndrome (IBS). It is estimated that fourteen percent of US adults suffer from IBS, making it an important an heavily researched topic (1). But has your doc brought up this funky acronym FODMAP? Let’s talk about it.
While scientists are yet to find a curse, there is one diet that looks promising: restriction of fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs). A 2017 review found that randomized controlled trials showed the low FODMAP diet leads to clinical responses in 50-80% of patients with IBS including improvements in bloating, flatulence, and diarrhea (2). In this article, we’ll break down what IBS is, what are FODMAPs, how people with IBS might benefit from a low FODMAP diet, and how a low FODMAP diet should be followed.
What is IBS?
IBS is a disorder characterized by recurrent gastrointestinal issues including abdominal pain and altered bowel movements. It is often considered a “diagnosis of exclusion” since there are no consistent biological markers, the symptoms are subjective, individual experiences vary, and it can be related to many other not yet identified conditions (3). Clinicians have tried to combat this ambiguity by creating the Rome IV diagnostic criteria, yet there is still debate over whether or not these guidelines are sufficiently accurate and precise.
Signs and symptoms of IBS are usually present for a long time (at least three months) and tend to include the following (4):
- Abdominal pain, cramping or bloating that is related to defecation
- Changes in appearance of stool
- Changes in how often you are having a bowel movement
Over time, IBS can have more serious implications. These include weight loss, nighttime diarrhea, rectal bleeding, iron deficiency anemia, unexplained vomiting, difficulty swallowing, and persistent pain. Clearly, it is not a good time.
What are FODMAPs?
FODMAPs are part of a group of carbohydrates found in a variety of plant foods. Instead of being digested and absorbed like other carbohydrates are, they reach the far end of your large intestine and become food for the bacteria in your gut (in other words, they act as prebiotics). For plenty of people, this can be a good thing by promoting a diverse microbial community, which has been linked to many health benefits (5).
However, for certain people who are sensitive to FODMAPs, this could lead to production of excess hydrogen gas, which triggers digestive symptoms such as bloating, gas and stomach pain. FODMAPs also draw liquid into the intestine, which may lead to diarrhea.
FODMAP is an acronym that stands for fermentable oligosaccharides. disaccharides, monosaccharides and polysaccharides.
How might people with IBS benefit from a low FODMAP diet?
As you can see, FODMAPs are present in a diverse assortment of nutrient-dense foods. So, restricting intake of these foods should only be considered if appropriate because it is challenging and requires careful planning and attention. Right now, the research does support efficacy in managing IBS symptoms with a low FODMAP diet.
There is compelling evidence to suggest that low FODMAP diets might significantly decrease stomach pain and bloating in people with IBS. For example, a meta-analysis of randomized control trials and non-randomized interventions found that following a low-FODMAP could improve severity of abdominal pain and bloating by 81% and 75%, respectively (7). The protocol has also been shown to reduce other commonly associated symptoms such as flatulence, diarrhea and constipation (8).
By helping to resolve digestive symptoms related to IBS, a low FODMAP diet might improve quality of life. Dealing with chronic gastrointestinal distress takes a toll on the people who suffer from it. Several studies have shown that this condition places a measurable burden on society (9). There is also some budding research suggesting that the low FODMAP diet might also help improve energy levels in people with IBS (10). However, this topic merits further study and the effect could be secondary to the overall relief of symptoms.
How should a low FODMAP diet be followed?
First of all, we want to emphasize that if you are suffering from IBS and would like to try a low FODMAP diet, it is important to work with a Registered Dietitian who has training and experience with the protocol. The diet is very intricate and requires educated supervision from a professional. A low FODMAP diet involves three phases:
Phase 1: Elimination
This is the not-so-fun part. For the first 1-2 months, you must strictly avoid all high FODMAP foods. Since there are so many foods on this list, many people use apps to help them navigate what to eat. We like the Monash University FODMAP diet app for this stage. During the restriction phase, you can only eat foods that are low in FODMAPs, including:
- Vegetables and legumes such as broccoli, carrots, kale, spinach, squash, etc.
- Fruit including kiwi, grapes, strawberries, pineapple, oranges, etc.
- Cereals, grains and nuts like wheat-free products, brown rice, popcorn, oats, etc.
- Dairy-free products such as almond milk, coconut yogurt, eggs, tofu, etc.
- Meats, poultry, fish, seafood as desired
The goal of this phase is to find relief in digestive symptoms by eliminating the high FODMAP foods. Once symptoms have improved, you can progress onto the next phase. If they do not improve, then this diet might not be right for you.
Phase 2: Reintroduction
In this stage, you slowly and systematically reintroduce the high FODMAP foods that you eliminated. This helps you identify what FODMAPs you tolerate (remember, there’s different types) and to determine how much of that FODMAP food you can tolerate without experiencing symptoms. To test if and how a food is tolerated, it is reintroduced one by one for three days. If no symptoms return, then that food is okay with you and can be included in your regular diet. If that new food makes you feel worse, then you might need to eliminate it altogether.
Phase 3: Personalization
By this point, you have identified what FODMAP foods you can tolerate and your threshold limit for those foods. Now, you can include those foods on a regular basis while continuing to avoid the foods that trigger symptoms.
The bottom line
The low FODMAP diet might help make IBS sufferers feel better, but it ultimately is a means to an end. Utilizing a low FODMAP diet can help those who suffer from untreatable digestive symptoms to discover what foods work for their body. It should only be utilized once other gastrointestinal conditions have been ruled out. This helps to make sure that other diseases, illnesses and injuries are not left untreated. Moreover, it should be executed alongside a Registered Dietitian to ensure appropriate and strategic implementation.
