What is the Low FODMAPs Diet?

Sarah Greenfield | November 28, 2017

It is estimated that about 10 to 15 percent of the population suffers from irritable bowel syndrome or IBS. This disorder is commonly characterized by changes in bowel habits like diarrhea, constipation, gas, bloating and abdominal pain or discomfort. SIBO, or small bacterial overgrowth, is a more specific condition that impacts digestion. Many people with IBS or digestive issues find SIBO to be the root cause. In both cases, a low FODMAP diet has been shown to be an effective tool for managing and decreasing symptoms. Before you start following this diet, it’s important to understand what foods contain FODMAPs and if a low FODMAP diet is right for you.

What are FODMAPs?

FODMAPs are carbohydrates that ferment in the digestive tract and lead to gas and bloating. The types of carbohydrates are Fermentable Oligo-saccharides, Di-saccharides, Mono-saccharides, and Polyols (FODMAP). The specific sugars that make up these carbohydrates include fructose, lactose, the polyols, sorbitol, mannitol, fructans, and galacto-oligosaccharides. Some people have a harder time breaking these carbs and sugars down, which can trigger gas, bloating and other symptoms of IBS.

Not everyone is sensitive to every fermentable sugar. The best way to discover sensitivities is to eliminate all sugars and then slowly reintroduce them back into the diet. Below are some common food examples of each fermentable sugar:

  • Fructose – mangoes, figs, guava, honey, agave, asparagus, sugar snap peas
  • Lactose – milk, cheese, yogurt, cream.
  • Polyols
    • Sorbitol – avocados, blackberries, peaches, plums, coconut, “unsweetened” chewing gums, and protein bars
    • Mannitol – celery, sweet potato, mushrooms
  • Fructans – cabbage, garlic, onions, shallots (green part only), leeks, snow peas, barley, oats, spelt, wheat, buckwheat, dried fruits
  • Galacto-oligosaccharides (GOS) – most beans such as lentils, chickpeas, kidney beans, as well as almonds, peas

Check out this app for a more in-depth overview of what foods to avoid.

When should you follow a low FODMAP diet?

If you’re diagnosed with SIBO or IBS, following a low FODMAP diet may help alleviate digestive symptoms. It’s important to understand that it’s not a long-term diet; it should only be followed for 2 to 6 weeks since the nutrient restrictions can negatively impact the gut microbiome. You should see a change in your symptoms within two weeks. If you don’t notice a difference, this diet may not be right for you. It is also important to note that this diet should not be combined with medication or specific supplements geared towards treating SIBO. It is always best to check with your doctor or healthcare practitioner before making a large dietary change.

IBS is a very broad term for many different digestive issues, and managing symptoms can be challenging. Work with your doctor or functional medicine dietitian to see if a low FODMAP diet is right for you. Healing your digestion and figuring out the root cause of digestive disturbances are the keys to optimal health.


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Sarah Greenfield

Sarah Greenfield studied nutrition at Pennsylvania State University, got her RD through UCLA and worked as a dietitian with a focus on ICU, trauma, digestive disease and wound care.

She created a nationwide school nutrition program and a nutrition-focused marathon training program for NutriBullet. Having completed several marathons, she got an advanced certification in sports nutrition to further her knowledge on coaching athletes to better health.

She started her own company, Fearless Fig, as a way to connect with people on a deeper level. She works with clients one-on-one, integrating advanced testing to restore digestive health, fuel endurance athletes, and make healthy eating achievable. She has been featured on Men's Health, Self, NBC with Lester Holt, KTLA with Lori Corbin and Dr. Hyman's Blog for her recipes and meal prep tips.

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