10 Common Questions About the Low FODMAP Diet Answered by Dr. Amy Myers

For Dr. Amy Myers, food is medicine. As both a medical doctor and a functional medicine physician, Dr. Myers has seen first-hand the power of nutritious foods like grass-fed meats and organic fruits and vegetables to support gut health. Today, she answers the top ten questions she commonly receives from clients and patients about the low-FODMAP diet.

If you have digestive issues, you’ve probably heard the term “FODMAP,” and may be wondering if it’s right for you. While a low-FODMAP diet has been shown to lessen the pain of digestive issues, the long-term solution is to identify and treat the underlying cause of your sensitivity to high-FODMAP foods.

In many cases, the root problem is SIBO or small intestinal bacterial overgrowth, a condition in which your gut flora becomes unbalanced. The bacteria living in the small intestine overgrow into the large intestine where they don’t belong.

And, if you’re interested in learning more about the low-FODMAP diet, here are the ten most common questions I get about it:

Who Should Try a Low-FODMAP Diet?

Australian research shows that about three out of four people with IBS (Irritable Bowel Syndrome) felt their symptoms ease immediately after starting a low-FODMAP diet. As much as 15% of the world’s population, or one in seven people, are affected by IBS. As many as 50% of those people are found to have SIBO, or small intestinal bacterial overgrowth.

What Exactly is a Low-FODMAP Diet?

Researchers at Monash University in Melbourne, Australia, developed a plan that limits certain kinds of carbohydrates that can irritate the digestive system. The intention is to limit, for a short period, eating short-chain carbs (more on that below!). I want to stress that this is a tool to help relieve painful and distressing symptoms while you work toward treating the root cause of the problem.

What about People with Histamine Intolerance?

Histamines are chemicals that tell your body to create inflammation. The symptoms can be localized in the stomach (appearing as cramps) or they can be found throughout the body in the form of unexplained rashes, flushing, fatigue, swelling, headaches, and hypertension among others. Avoiding high-FODMAP foods can drastically reduce histamine release.

What does the Acronym FODMAP Stand For?

The names of the five short-chain carbs to avoid are pretty unwieldy, so the researchers who identified the food groups condensed them into the FODMAP acronym. Here’s what each means:
Fermentable: Carbs that, when undigested, are fermented by the gut bacteria, producing gases.
Oligosaccharides: Sugars including fructans and galacto-oligosaccharides (GOS) found in wheat, barley, onions, garlic, and legumes.
Disaccharides: Think lactose, which is found in dairy products such as milk, soft cheeses, and yogurt.
Monosaccharides: Fructose, a simple sugar found in honey, apples, high-fructose corn syrup, and agave.
Polyols: Includes sorbitol and mannitol, which are found in some fruit and vegetables and are used in artificial sweeteners.

Why Are These Carbohydrates Irritating?

Because these five carbs are either digested very slowly or completely indigestible, they aren’t properly absorbed by some people. Furthermore, they can draw water away from the rest of the body into the bowel, causing imbalances. Gut bacteria trying to break down these carbs can ferment them, producing gas. Additionally, those gut bacteria, feasting on slow-moving carbs in your gut, can also overgrow into parts of your digestive tract where they don’t belong.

Will a Low-FODMAP Diet Cause Constipation?

It depends on what you eat. While some fruits and vegetables are restricted, there are plenty of foods that you can enjoy that will help you move things along, including antioxidant-rich blueberries, which also pack in a healthy dose of fiber. Drinking a lot of water is one of the best ways to ensure regular bowel movements.

How Does the Diet Make Me Feel Better?

Not only can avoiding FODMAPS improve digestion by reducing the amount of indigestible fiber in your system and the gases produced while it ferments, but it can also impact the release of histamines that cause your immune system to go into overdrive. Fewer histamines being released means less inflammation and irritation.

How Will I Know What Foods to Avoid?

Researchers at Monash University have produced a comprehensive list of high- and low-FODMAP foods and they continue to evaluate additional choices.

What Can I Eat on a Low-FODMAP Diet?

One of the best parts about this eating plan is that it’s rich in all types of protein including fish, poultry, beef, lamb, and pork. Protein powders can also be a valuable part of a low-FODMAP diet, however, you’ll want to avoid any that include whey, dairy, or pea proteins. If you do opt for a protein powder for a breakfast smoothie or snack, I recommend my Paleo Protein powder, which is sourced from non-GMO, hormone- and antibiotic-free, grass-fed beef.

How Do I Follow a Low-FODMAP Diet?

The plan calls for a three-step approach. In step one, you’ll restrict your intake of high-FODMAP foods to reduce distress. Once your symptoms have resolved, you’ll move on to steps two and three. In step two, you’ll reintroduce foods one at a time into your diet, and monitor your reactions to determine which cause problems and which don’t. The final step is learning your perfect balance (regarding quantity and frequency) of high-FODMAP and low-FODMAP foods.

One of the best parts about the low-FODMAP diet—and something I hardly ever get to say as a medical doctor—is that about three out of four people with IBS had their symptoms ease right away after starting a low-FODMAP diet. They felt the most relief after seven days or more on the plan. However, the long-term solution is to identify and treat the underlying cause of your sensitivity to high-FODMAP foods, which, in many cases, is SIBO.