July 2022The Lowdown on the Low-FODMAP Diet
By Lynne Lalor
Through the rise of social media, it’s never been easier to find a new elimination diet to try. With all of them swearing to solve your problems, trying to find “the right one” can feel like doing a word search with no word bank. One diet you might have come across is the low-FODMAP diet. With promises of soothing gastrointestinal (GI) distress, you may have asked “is this right for me?”. Maybe! But not so fast—let’s look at the fine print before deciding.
First, what are FODMAPs?
FODMAP stands for Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols. These are nondigestible, short-chain, carbohydrates that pull water into the GI tract as they pass through, increasing the volume of the intestines. Bacteria that live in the GI tract also easily ferment these carbohydrates, creating gas and causing an increase in volume. For most people, these normal processes don’t cause issues. For those with irritable bowel syndrome (IBS), the expansion of the stomach from the water and air may cause distress on their more sensitive GI systems, leading to the common symptoms of IBS like abdominal pain, excessive gas, diarrhea, and bloating. Some examples of high FODMAP foods include: honey, mango, wheat, milk, garlic, onion, and beans.
What is the low-FODMAP diet?
The low-FODMAP diet is a type of elimination diet where foods that are high in FODMAPs are first completely removed from the diet (the elimination phase), and then slowly added back in (the reintroduction phase). The goal of this diet is to find “trigger food(s)” or the food(s) that cause the most frequent and severe problems. High FODMAP foods aren’t automatically problematic for all people with GI issues; sensitivity varies from person to person. The low-FODMAP diet is intended to find some clarity on what food(s) may be causing problems for that person. In other words, just because garlic is high in FODMAPs doesn’t mean it’s a trigger food for everyone with IBS. Also, the amount of the FODMAP-containing food plays a role in symptoms. Many people can continue to eat certain FODMAP foods in small amounts, so the reintroduction phase is critical for determining the tolerated amount. The whole process can take months.
Risk of the low-FODMAP diet
While the low-FOMAP diet can be helpful for some people, it’s not a great option for others, and there are important risks to recognize. For starters, this diet is highly restrictive. While the initial restrictive phase is only temporary, nutritional deficiencies—especially inadequate fiber intake—can occur and may worsen GI symptoms. Additionally, the process of restricting foods can foster an environment for disordered eating making the diet unsuitable for anyone with a history of disordered eating or who may be at risk for developing disordered eating.
It should also be emphasized that the low-FODMAP diet is only one type of treatment option for people diagnosed with IBS and is often used with other therapies such as behavioral and medical interventions. The first step is to talk with your doctor to rule out other GI conditions that can have similar symptoms such as Crohn’s disease, small intestinal bacterial overgrowth (SIBO), and celiac disease. These conditions often require medical management and/or a different nutritional approach. Furthermore, this diet also may not work, even for those with IBS. According to Monash University’s research, GI symptoms have improved in 75% of people who were diagnosed with IBS and followed a low-FODMAP diet. As FODMAPs are not the root cause of IBS, restricting them isn’t going to work for all people with IBS.
Trying the diet
If you’re looking for GI symptom relief and are thinking about trying the low-FODMAP diet, speak with a registered dietitian nutritionist (RDN) first to discuss different treatment options. As IBS treatment is unique to each person, RDNs will assess, supervise, and collaborate with you to create a plan that best meets your needs. They’ll ensure that the diet is customized to your situation and will carefully plan each step to prevent common issues. An RDN will also ensure that the selected low FODMAP approach is evidence-based (given that there are several misguiding versions of the “low FODMAP diet” available on the Internet). While it’s no magical diet, research consistently shows that, with proper guidance, the low-FODMAP diet may help improve symptoms and quality of life for those with IBS.
Get to know the Author:
Lynne Lalor is from Colorado Springs, Colorado, and has lived in Colorado almost her whole life. Lalor graduated in May with a Bachelor of Science degree in Food Science and Human Nutrition. She was the KRNC Student Spotlight in April 2022, learn more about Lalor here.
More Information:
For additional resources to healthy eating, check out these programs from our registered dietitian nutritionists. Find delicious and healthy recipes on our Recipes page! More health tips are also available at the College of Health and Human Sciences Pinterest board. Lastly, don’t forget to sign up for the KRNC monthly newsletter!
FAQs
The low FODMAP diet can be helpful for symptom management but is not a direct treatment for IBS or SIBO. Long term strict FODMAP restriction can have adverse effects such as a reduction in Bifido and butyrate producing bacteria, and creating anxiety and fear around food.
What foods are unlimited on low FODMAP diet? ›
Instead, base your meals around low FODMAP foods such as:
- Eggs and meat.
- Certain cheeses such as brie, Camembert, cheddar and feta.
- Almond milk.
- Grains like rice, quinoa and oats.
- Vegetables like eggplant, potatoes, tomatoes, cucumbers and zucchini.
- Fruits such as grapes, oranges, strawberries, blueberries and pineapple.
On average, each patient showed intolerance to 2.5±2 FODMAPs. The most common FODMPs to trigger symptoms were fructans (56%) and mannitol (54%), followed by GOS, lactose, fructose, sorbitol, and glucose (respectively 35%, 28%, 27%, 23%, and 26%).
What happens if you stay on the low FODMAP diet too long? ›
If you skip these foods for too long, you may starve helpful bacteria colonies and cultivate unhealthy bacteria. Over time, if you follow only strict low FODMAP eating, you might notice yourself getting more tired, having more headaches, constipation, muscular weakness, or getting sick more easily.
Why do I feel worse on a low FODMAP diet? ›
You may also be eating more starches and sugars from hyper-processed gluten free, low FODMAP packaged foods than usual, which may overwhelm the absorption capacity of a sensitive, hyper-active gut. If you suspect this, try eating more fruits, vegetables, nuts and seeds and see how you feel.
Is coffee low in FODMAP? ›
Yes, instant coffee (both regular and decaf) is considered low FODMAP. Monash lists a low FODMAP serving as 4g or 1 heaped teaspoon mixed with 230ml water. Keep in mind that coffee can irritate the gut and stimulate gut motility, separate to the issue of FODMAPs.
What is not allowed on low FODMAP? ›
High FODMAP foods that you should avoid include:
Fructose: Fruits (including apples, mangos, pears, watermelon), honey, high-fructose corn syrup, agave. Lactose: Dairy (milk from cows, goats, or sheep), custard, yogurt, ice cream. Fructans: Rye and Wheat, asparagus, broccoli, cabbage, onions, garlic.
Can I eat peanut butter on a low FODMAP diet? ›
Peanut Butter is Low in FODMAPS
While almonds, cashews, and pistachios are fairly high in FODMAPs, peanuts, pecans, and walnuts are considered low FODMAP foods. This is because peanuts are technically part of the legume family, they're safe for a low FODMAP diet.
What are the worst FODMAP foods? ›
Wheat, barley, rye, and wheat-containing products like breads, cakes, pasta, cereal, and pastries are high in FODMAPs, so they're a key food group to avoid for management of IBS symptoms. In fact, a 2015 study suggested that a gluten-free diet may improve IBS symptoms in around half of the population.
What foods have no FODMAPs at all? ›
FODMAP “Free” Foods List
- Alfalfa.
- Arugula.
- Bamboo shoots (fresh/canned)
- Beansprouts.
- Bell Peppers (red)
- Capsicum (red)
- Carrots.
- Choy sum.
Some of the highest FODMAP beans and legumes include baked beans, black-eyed peas, broad beans, butter beans, chickpeas, kidney beans, lentils, soybeans, and split peas. Sweeteners are hidden everywhere in the Western diet and they can increase the total FODMAP content of even low-FODMAP foods.
What are the negatives of the fodmap diet? ›
Risk of the low-FODMAP diet
For starters, this diet is highly restrictive. While the initial restrictive phase is only temporary, nutritional deficiencies—especially inadequate fiber intake—can occur and may worsen GI symptoms.
Why am I gaining weight on a low FODMAP diet? ›
A person with IBS may try to eliminate certain high FODMAP foods from their diet and choose safer foods instead. This approach can lead to weight gain if their chosen foods are high in carbohydrates and fats. A low FODMAP diet does exclude a range of nutritious foods.
Why am I so tired on a low FODMAP diet? ›
Unfortunately, many newbies to the low FODMAP diet remove foods entirely from their diet instead of swapping them. Deleting foods from your diet can reduce the calories (energy) available for your body and your nutrient intake, which can make you feel tired or headachy.
What happens to your body on a low FODMAP diet? ›
The low-FODMAP diet temporarily restricts these carbohydrates in order to relieve uncomfortable symptoms and give your digestive system a rest. Removing irritants gives your gut lining a chance to repair itself and can help restore a healthy balance of gut flora.
What are the risks of FODMAP foods? ›
FODMAPs are a group of fermentable carbohydrates. They are notorious for causing common digestive issues like bloating, gas, stomach pain, diarrhea and constipation in those who are sensitive to them. This includes a surprising number of people, particularly those with irritable bowel syndrome (IBS).
Who should avoid FODMAP foods? ›
Many foods considered high in FODMAPs are healthy foods otherwise, but they can cause symptoms in some people with a sensitive gut; particularly people with IBS or other bowel diseases and disorders like SIBO.
What are the challenges of low FODMAP diet? ›
Additionally, there are challenges such as those in precisely quantifying FODMAP content, potential exacerbation of constipation, links to eating disorders, and limited long-term data. While some studies report sustained benefits, more research on the diet's long-term efficacy and safety is needed.
