Much has changed in the low-FODMAPs world since I first wrote about it three years ago. It is no longer a completely unfamiliar term to those in the digestive world, doctors often will suggest the diet to patients, and I see many clients who have already started the diet before they come in to see me. Word has definitely spread about the Fodmaps elimination diet. But with this increased awareness have also come a lot of misconceptions. Let’s take another look at the Fodmaps elimination diet to see where we are today.

For those who missed my last article, FODMAPs is an acronym that stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. They are a group of shorter-chain carbohydrates that are rapidly fermentable and osmotically active. Sometimes they pull water into the intestines, leading to uncomfortable swelling and diarrhea. They also may be poorly absorbed in the small intestine. When they land in the large intestine, they are rapidly fermented by our resident gut bacteria or microbiota. It is healthy to have a robust microbiome, but some people experience more fermentation than others, leading to distressing symptoms like gas, bloating, distension and/or pain. Diarrhea, constipation, or a combination is also common.

FODMAPs encompass all food groups, which is part of why the diet can be confusing. High-Fodmaps foods include the lactose in dairy (fluid milk, soft cheeses, ricotta, cottage cheese, yogurt); certain grains such as wheat, rye and barley (but this is not a gluten-free diet); many vegetables, including onions, garlic, peas, sugar snaps, Brussels sprouts, cauliflower, asparagus and beets; fresh and dried fruits including apples, peaches, apricots, mangoes, plums, watermelon, dates and raisins; most legumes, including beans, peas and broad beans (but some canned and drained lentils and chickpeas are okay); and many sweeteners, condiments, additives, and sugar alcohols, including high fructose corn syrup and honey, garlic/onion powder, inulin, and sugar alcohols such as mannitol, sorbitol and xylitol. This is a very short and condensed list. Complete lists are much longer and nuanced, with many Fodmaps foods having caps at certain quantities. For example: lactose-free dairy is allowed. Wheat or spelt sourdough bread is allowed as long as it was made with a true sourdough method, but other wheat and spelt products are not. Food preparation can play a role: cooking foods can condense the Fodmaps and therefore reduce allowable quantities (such as for spinach), and dried fruits sometimes are not allowed, while the fresh ones are (raisins versus grapes). The devil is in the details where Fodmaps are concerned.

One misconception is that the low-Fodmaps diet is appropriate for everyone. On the contrary, there are certain individuals for whom the diet is not a good fit. For example, if you do not regularly consume high-Fodmaps foods, or did not consume them in the past, the diet is not likely to help. Have you tried standard IBS therapies first before embarking on the diet? This is always a good idea. If you suspect celiac disease, this should be ruled out before you embark on the diet because, while it is not a gluten-free diet, it does eliminate many gluten-containing foods; celiac disease is much harder to diagnose once you have eliminated gluten from your diet. There are other individuals, including those with eating disorders, for whom this diet may not be appropriate. The list goes on. Trained dietitians will be knowledgeable about this and can help you decide if this is right for you.

Another common misconception is that the low-Fodmaps diet is just a list of low- and high-Fodmaps foods. End of story? Not quite. While there are many lists out there, the low-Fodmaps diet is much more nuanced than that. First, it is a learning diet and not a forever diet. There are three phases: The elimination diet, the reintroduction phase, and the adjustment phase. The elimination phase or low-Fodmaps phase should last roughly two to three weeks and up to six weeks. The reintroduction phase is where FODMAPs are reintroduced, one at a time for a certain number of days and in a methodical manner. Careful notes are taken on a food-symptom journal to help clarify one’s reaction. This can take six weeks or longer if done correctly. In the end, you will have learned which foods do and don’t provoke symptoms, in which amounts, and to what degree. Why not stay on the elimination diet forever? Because certain FODMAPs are especially beneficial to the microbiome. Many Fodmaps are their preferred food, and when they are starved of this food, their numbers dwindle. Please see my other articles for more about the microbiome and its importance in health.

Another important point: It is a low-Fodmaps diet, not a no-Fodmaps diet. The goal is not to eliminate all Fodmaps, but rather to decrease them to a level at which symptoms are minimized or completely gone, in a best-case scenario. This means eating some lower-Fodmaps foods is fine and being mindful of portion sizes for each meal is equally important. Ask yourself if the general Fodmaps load of your meal is small.

Speaking with a professional can be helpful with all of this, including finding a reliable resource or references. There is a lot of information out there, some of it conflicting or questionable. Make sure yours is accurate. If you are already well into the diet, it can be good to have another set of eyes to review to what extent you are following it correctly. This will help ensure that your results will be accurate; there cannot be much learning from the diet if it is not followed correctly.

Last, there are a few different options for the reintroduction phase; it is not one size fits all. For those who are interested in the diet but feel overwhelmed by the amount of material out there, there is another, easier option for you. It involves doing a general sweep, substituting common lower-Fodmaps foods for higher-Fodmaps ones. This approach can still reap benefits, while also helping to minimize worries or anxiety around the diet.

Fodmaps is an evolving science. New research comes out on a steady basis. It is also not as simple as it appears upon first glance, and many misconceptions surround its use and implementation. If you feel yourself getting confused, consider speaking with a knowledgeable dietitian who can help you through the nuances. Once you get the hang of it, you will likely learn a great deal about Fodmaps and if or how they affect you and your digestion.

The information provided in this article is intended for general use only and is not to be used in place of medical advice from a licensed health professional.