What Is the Low FODMAP Diet?
Today's diets often share key similarities—they boost your health and assist with weight loss. The low FODMAP diet, however, is popular for an entirely different reason: It aims to reduce the symptoms associated with one of the most common intestinal disorders, irritable bowel syndrome (IBS).
The acronym signifies the different types of short-chain carbohydrates found in many of the foods we eat: fermentable oglio-saccharides, disaccharides, mono-saccharides, and polyols. "Some people have difficulty absorbing these groups of carbohydrates, and can get gastrointestinal distress, including severe gas, abdominal pain, bloating, swelling in the abdomen, nausea, diarrhea, and even constipation, from consuming foods that contain them," explains Roger E. Adams, Ph.D., a personal trainer, doctor of nutrition, and the owner of eatrightfitness. "The diet itself is followed in three distinct phases: elimination, reintroduction, and liberation." Ahead, everything you need to know about the low FODMAP diet, including its origin story and benefits.
The low FODMAP diet is relatively new.
This style of eating was discovered roughly 12 years ago by a team of researchers from Monash University in Melbourne, Australia. "The group was attempting to explain how a subgroup of carbohydrates (short-chain carbohydrates) contribute to symptoms related to maldigestion, like gas, bloating, and abdominal pain," explains Kevin E. Woods, M.D., M.P.H., chief of Interventional Endoscopy, Gastroenterology & Nutrition, at Cancer Treatment Centers of America (CTCA) Atlanta. "Its success has also been further tested and validated by researchers and clinicians around the world in multiple peer-reviewed trials and studies."
It's best for IBS sufferers.
Individuals suffering from IBS are most likely to benefit, according to Elliot Schwarzenberger, M.D., a gastroenterologist with Woodholme Gastroenterology Associates in Queens, New York. "There are several subtypes of IBS, but the low FODMAP diet tends to work for almost all of them, including IBS-diarrhea predominant, IBS mixed, and IBS unclassified," he says. "By following a low FODMAP diet, one can reduce his or her symptoms of gas, bloating, and abdominal pain, as well as improve bowel habits."
Unless you have IBS or another related condition—such as SIBO (small intestinal bacterial overgrowth)—it's not wise to hop on the low FODMAP bandwagon. "Many of the foods restricted on this diet are beneficial prebiotics, which support good bacteria in your gut, so you wouldn't want to create new issues by removing them—especially if they aren't giving you any temporary relief or answers," says Chelsea Rose, a Los Angeles-based certified health coach and founder of Healthy with Chelsea.
Start in the elimination phase.
The first phase, elimination, involves cutting out all foods high in fermentable oglio-saccharides, disaccharides, mono-saccharides, and polyols, including wheat, garlic, onion, and fruits (yes, all fruits); Monash University has since created an app that lists out all offending foods, which can actually differ based on quantity of consumption. This phase, Dr. Adams explains, is typically followed for four weeks straight. "The second phase, reintroduction, is when high-FODMAP foods are slowly introduced back into the diet to determine which of the five sugars trigger the gastrointestinal issues," he says. "This phase takes as long as necessary to find the offending foods." Lastly, patients enter the third and final phase, which is dubbed liberation. "This is when you have found the offending foods and are now back to a normal diet, free from symptoms," he adds.
Keep a journal along the way.
For optimal success, Dr. Adams suggests following this diet closely and journaling the foods you eat, along with any symptoms you experience. "As you eliminate the high FODMAP foods, you need to take the whole four weeks to allow your body to get back to normal and reduce symptoms and inflammation—you create a level playing field, so to speak. When you start to add them back in during phase two, you identify offending foods more easily," he says. "During reintroduction, write down each food you try, how you feel after you eat it, and any symptoms you experience hours later. This will help you determine whether this food will be part of your normal diet or not."
Be sure to read food labels.
You might be surprised by which foods are or are not high FODMAP. To stay compliant, Dr. Schwarzenberger says not to assume, since high-FODMAP foods don't necessarily fall under traditional "healthy" or "unhealthy" categories (cauliflower, for example, is off limits during the elimination phase). He suggests checking ingredient labels and double checking, specifically, for high fructose corn syrup, which is a commonly used high-FODMAP substitute for sugar.
Alert your health care provider if symptoms worsen.
If you are experiencing new intestinal symptoms while on this diet, Dr. Woods recommends alerting your care provider as soon as possible; it's also best to work with a registered dietitian or health care provider throughout the process. Ultimately, though, if you have been diagnosed with IBS, this method is likely to help. "If your symptoms are consistent with a diagnosis of irritable bowel syndrome, the low FODMAP diet has been proven to help decrease the intensity and frequency of functional gastrointestinal symptoms," he says.