Diets Dissected: Low-FODMAP
Welcome to Diets Dissected, a blog series where we team up with Western’s registered dietitians to take a closer look at popular diets. Our goal? To give you clear, fact-based information so you can make informed decisions about what works best for your body and your lifestyle.
Before we dive in, a quick note: At Western, we don’t take a one-size-fits-all approach to nutrition. In fact, we’re not big fans of restrictive diets. Our philosophy is holistic, body-positive, and rooted in long-term health, not quick fixes. That said, we also know that some diets can offer benefits when used thoughtfully and with good guidance. That’s why we’re here to unpack the science, talk through the pros and cons, and help you sort out what’s worth considering.
In this blog, we’re exploring the Low-FODMAP diet. You might have heard the term floating around, especially in conversations about gut health, but what does it actually mean? Whether your goal is to ease digestive discomfort, better understand how certain foods affect you, or simply stay informed, we’ll break it down step-by-step. Let’s dive in!
What is the Low-FODMAP diet?
The Low-FODMAP diet is a short-term eating plan designed to help people with sensitive digestive systems identify foods that trigger uncomfortable symptoms. FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols—a mouthful, but essentially it refers to a group of carbohydrates that are harder for the gut to digest.
“FODMAPS can cause symptoms like gas, bloating, and stomach pain. Removing FODMAP carbohydrates allows your gut lining to repair itself and restores balance within the gut microbiome,” says Western dietetic intern, Ella Wall.
Here’s what happens: normally, carbohydrates are broken down in the small intestine and absorbed into the bloodstream. But FODMAPs don’t break down easily. Instead, they travel through the small intestine largely intact, pulling in extra water along the way. Once they reach the large intestine, the bacteria living there get to work fermenting them—a process that produces gas and other byproducts. For some people, that combination of extra water and gas can cause bloating, pain, diarrhea, constipation, or a mix of all three.
Do FODMAPs affect everyone negatively?
Not everyone has an adverse reaction to FODMAPs. In fact, many foods high in FODMAPs are healthy and beneficial for most people, helping feed the “good” bacteria in the gut. But for individuals with conditions like irritable bowel syndrome (IBS), the normal digestive process can feel anything but normal. The Low-FODMAP diet helps by temporarily cutting out the highest-FODMAP foods, giving the digestive system a break and reducing symptoms.
How does the low-FODMAP diet work?
The Low-FODMAP diet isn’t about cutting out foods forever. It’s a structured process designed to help you learn which foods your body handles well and which ones might be triggering symptoms. It typically unfolds in three phases, each with a specific purpose:
1. Elimination Phase
For about two to four weeks, you’ll avoid foods that are known to be high in FODMAPs. This includes certain fruits, vegetables, dairy products, grains, and legumes (keep reading for a more detailed breakdown). At first glance, it can feel restrictive, but it’s not about starving yourself or eating bland food. There’s still a wide variety of low-FODMAP options in every food group to keep meals satisfying and nutritionally balanced.
2. Reintroduction (or Challenge) Phase
Once symptoms have improved, you’ll begin reintroducing foods one at a time in a controlled way. This step helps identify which specific foods or FODMAP groups are actually causing trouble. It’s a bit like detective work for your digestive system—testing, observing, and learning which foods you tolerate and which ones you don’t.
3. Personalization (or Maintenance) Phase
After reintroduction, you’ll settle into a customized eating plan that keeps the foods that work for you and limits (but doesn’t necessarily eliminate) the ones that trigger symptoms. For many people, this means only a handful of foods need to be avoided, while most can be enjoyed without worry. The ultimate goal is to expand your diet, not shrink it, giving you confidence and comfort around eating again.
Because the Low-FODMAP diet involves both restriction and testing, it’s best done under the guidance of a registered dietitian. They can help you create balanced meal plans, make sure you’re not cutting out key nutrients, and guide you through each phase with less stress and more clarity.
What You Can and Cannot Eat on a Low-FODMAP Diet
A Low-FODMAP diet isn’t about “good” and “bad” foods. It’s about learning which foods your gut can handle comfortably. Different foods contain different types and amounts of FODMAPs, so the key is knowing which ones tend to cause trouble, and in what portion sizes.
Here are some general examples to give you an idea:
Low-FODMAP (Generally Safe) Foods
These foods are less likely to trigger symptoms during the elimination phase:
Proteins: Plain cooked meats (chicken, turkey, beef, pork), eggs, firm tofu, tempeh, fish, shellfish.
Fruits: Grapes, oranges, pineapples, strawberries, blueberries, kiwi, unripe bananas (less sweet).
Vegetables: Bell peppers, carrots, zucchini, cucumbers, green beans, spinach, lettuce, tomatoes.
Grains & Starches: Rice, quinoa, oats, corn, gluten-free breads and cereals.
Dairy (lactose-free): Lactose-free milk, hard cheeses (cheddar, Parmesan), lactose-free yogurt, plant-based milks (almond, oat, or rice milk).
Other: Nuts and seeds (in moderate amounts, except high-FODMAP varieties like cashews and pistachios), herbs, oils, vinegars.
High-FODMAP (Common Triggers to Avoid at First)
These are foods that are more likely to cause digestive discomfort in sensitive guts:
Proteins: Processed or seasoned meats (sausages, deli meats with added high-FODMAP ingredients), most legumes (lentils, chickpeas, kidney beans, black beans).
Fruits: Apples, pears, watermelon, cherries, peaches, nectarines, plums, ripe bananas.
Vegetables: Onions, garlic, cauliflower, mushrooms, Brussels sprouts, asparagus, artichokes.
Grains & Starches: Wheat, rye, barley (in large amounts — especially in breads, pastas, crackers).
Dairy: Milk, soft cheeses, yogurt, ice cream (all containing lactose).
Sweeteners: Honey, high-fructose corn syrup, sugar alcohols (sorbitol, xylitol, mannitol—often found in sugar-free gums and candies).
Important: Some foods aren’t strictly “off limits” but need careful portion control. For example, a few slices of avocado may be fine, while half an avocado could trigger symptoms. That’s why it’s important to follow the elimination and reintroduction steps carefully, ideally with a dietitian, to discover your personal tolerance levels.
The ultimate goal isn’t to keep avoiding high-FODMAP foods forever. It’s to figure out which specific ones bother you and in what amounts, so you can enjoy as much variety as possible without discomfort.
Who should try the Low-FODMAP diet?
The Low-FODMAP diet was designed with a very specific purpose: to help people with sensitive digestive systems identify food triggers. It isn’t meant as a general “healthy eating plan” or a weight-loss tool. Instead, it’s a targeted approach for those struggling with chronic gastrointestinal symptoms that haven’t improved with other changes.
You might consider a Low-FODMAP diet if:
You have IBS (Irritable Bowel Syndrome): This diet is one of the most well-researched approaches for reducing IBS symptoms like bloating, abdominal pain, diarrhea, and constipation.
You experience unexplained digestive discomfort: Persistent gas, cramping, or changes in bowel habits that interfere with daily life may be linked to FODMAP sensitivity.
You’ve ruled out other medical causes: Before trying a Low-FODMAP diet, it’s essential to speak with your healthcare provider to make sure there’s no underlying condition (such as celiac disease, IBD, or an infection) that requires a different treatment.
You want to identify specific food triggers instead of broadly restricting your diet: Rather than eliminating entire food groups forever, the Low-FODMAP process helps you figure out which foods actually cause problems and which are safe to enjoy.
This diet isn’t for everyone. People without digestive symptoms don’t need to restrict FODMAPs, and because it can be complex, it’s best to follow it under the guidance of a registered dietitian. A professional can help keep your meals balanced, walk you through each phase step-by-step, and ensure that the focus stays on learning, not unnecessary restriction.
Potential benefits of the Low-FODMAP diet
When used correctly, the Low-FODMAP diet can make a meaningful difference in the day-to-day lives of people with sensitive digestive systems. Here are some of the biggest benefits from Western dietitian Stephanie Nelson and dietetic intern Ella Wall:
Relief from IBS symptoms: Research shows that many people with irritable bowel syndrome experience less bloating, abdominal pain, gas, diarrhea, or constipation after following a Low-FODMAP plan.
A clearer picture of personal triggers: Instead of guessing which foods might be causing discomfort, this diet provides a structured way to test and identify specific culprits.
A more flexible long-term eating pattern: Once you know which foods truly cause problems, you can reintroduce everything else, making your diet less restrictive than broad “elimination” approaches.
Improved confidence around eating: Understanding your body’s responses can help reduce the anxiety that often comes with mealtimes when you’re not sure what’s safe to eat.
Better overall quality of life: For many, simply feeling comfortable after meals and not having to plan life around digestive symptoms can be a huge relief and take the stress out of eating.
Potential downsides of the Low-FODMAP diet
While the Low-FODMAP diet can be a powerful tool for easing digestive discomfort, it isn’t without challenges. Here are some of the biggest downsides from Stephanie and Ella:
It’s restrictive. The elimination phase can feel overwhelming, especially when you’re suddenly avoiding foods you’ve eaten for years. Eating out or cooking for a family can take more planning.
Risk of missing nutrients. If high-FODMAP foods include many of your usual fruits, vegetables, or grains, it’s easy to fall short on fiber, vitamins, or minerals, especially if the diet is followed too long without reintroduction.
It’s meant to be temporary, not permanent. Some people stay in the elimination phase longer than recommended, which can unnecessarily limit variety and even disrupt a healthy gut microbiome.
Food anxiety can creep in. For those already prone to stress around eating, carefully monitoring foods and symptoms may increase anxiety or lead to overly cautious food choices.
It doesn’t fix everything. Not all digestive symptoms are related to FODMAPs. If symptoms don’t improve after a proper elimination phase, it’s a sign to revisit your healthcare provider rather than keep restricting.
These challenges don’t mean the Low-FODMAP diet is unsafe or ineffective, only that it’s best approached with the right expectations, good support, and a focus on learning, not restriction.
Dietitian recommendation
Thinking about trying a Low-FODMAP diet? Here’s what Stephanie and Ella advise:
“We can definitely get behind the low FODMAP diet, given you have a legitimate reason for wanting to try it out. This diet certainly can offer relief to those who struggle with IBS or related conditions; however, if you are only experiencing mild digestive discomfort, we suggest you try other options first. Digestive issues may arise for a multitude of reasons, for example: irregular eating patterns, lactose intolerance, lack of sleep, and stress, to name a few. If you have exhausted other options or have been prescribed a low FODMAP diet, we highly recommend you seek guidance from a dietitian in order to properly follow the diet and get results!”
Thinking of trying the Low-FODMAP diet?
If you’ve been struggling with persistent digestive discomfort, the Low-FODMAP diet may be a helpful tool, but it’s not something you should have to figure out on your own. The best results come from following the plan carefully, knowing what to watch for, and having professional support along the way.
If you’re curious about trying this diet or you’d like to explore other nutrition strategies to address gastrointestinal issues, we invite you to connect with one of Western’s registered dietitians. Our team is here to help you understand your options, build a plan that works for your lifestyle, and give you peace of mind about what’s on your plate.
Ready to take the next step? Schedule a consultation with a Western dietitian today, and let’s work together toward more comfortable, confident eating.
