top of page

FODMAPs, Part 3: What the Practitioner Needs to Consider

I’ve previously written about what FODMAPs are (part 1) and how to apply a low-FODMAP diet (part 2).

Part 3 of my FODMAPs series reviews:

  • Why gluten avoidance on its own isn’t always the best answer,

  • Issues with the challenge phase,

  • How FODMAP quantities in the food system were derived, and

  • The cumulative effect of FODMAPs at a snack or meal.

The final installment, part 4, will be an in-depth look at common sports foods (e.g., gels, Gatorade) and how to feed a FODMAP-sensitive athlete during competition.

Simply Eliminating Gluten May Not be the Solution

When I first began working with endurance runners, a sport involving a jostling gut, I noticed many avoided gluten—especially in the hours leading up to a workout.

Reading more into FODMAPs research, the more likely culprit may be the fructan family—one that includes the gluten-containing items wheat, rye, and barley, in addition to various other non-gluten, yet problematic, items.

If you have an athlete who has cut out gluten, but symptoms remain, dive deeper and evaluate if high-fructan options are rampant throughout their day.

Remember: If an athlete has not returned to their baseline of feeling normal, and are only feeling slightly better once avoiding gluten on its own, more work needs to be done (see below).

The Challenge Phase: Reintroducing Groups

Let’s say you placed an athlete on a low FODMAPs diet for 2-6 weeks (i.e., until symptoms diminished or consistently weakened). The next phase of the diet is to reintroduce “challenge foods” per FODMAP subgroup to evaluate the troublesome group(s) (read part 2 if this phase doesn’t sound familiar).

However, reintroduction doesn’t mean using any “high” food from a group. Like in a research study, a scientist treats groups A and B the same, except for changing one factor in group B. This factor is what the researcher is manipulating to learn if a change in condition exists.

Similar to the FODMAPs challenge phase, if you were to evaluate the athlete’s response to fructans, but provided them with a challenge food that was high in multiple FODMAPs, you wouldn’t discover what group(s) was the culprit.

For instance, 1 cup of diced watermelon is considered high in fructose, fructan, and mannitol (i.e., polyol). Meaning if watermelon were used as a challenge food and the athlete reported negative symptoms, you wouldn’t know if it were one or a combination of the above FODMAPs that were acting together to wreak havoc on the gut.

Rather, the recommended challenge foods per group are listed in the below table.

Country-Specific FODMAP Data

Much of the research surrounding FODMAP levels in the food system comes from Monash University in Melbourne, Australia. Their research is based on food available in Australia—not the United States.

This means that an item labeled “low” in Australia could be “medium” or “high” in the United States, especially if the item’s ingredients greatly differ. For instance, in the United States high-fructose corn syrup is a readily available, inexpensive ingredient for food companies to use—meaning its presence is common in this country's products (read: excess fructose).

Researchers have discussed the need for country-based FODMAP food system data to be established.

In addition to the FODMAPs app, Monash University has a food certification program that allows companies to have their products designated and labeled as “Monash University Low FODMAP Certified™”. Certified American brands include:

Granted, if a food product lacks the certification, it doesn't mean the food isn't FODMAP friendly. Like anything listed on the front of a package, labels help someone grocery shopping quickly scan similar products and find what they're looking for.

Without the certified label, you'll need to read the ingredients list and search for the presence of problematic ingredients.

Without Ample American Data, What Should a Dietitian Do?

The following FODMAP levels are considered the cut-off values of grams per serving for an item to be considered as “low”:

Clear as mud.

Unlike calories or grams of protein per serving, there is no legal requirement for food companies to list grams per serving of specific FODMAPs within a package's nutrition label. This is why the Monash App, the university's food certification program, and the Australian FODMAP tables are so helpful—even if they aren’t always country-specific.

With whole foods, like fresh produce or beans, the quantities of FODMAPs are probably similar from country-to-country. For instance, American dietitian Kate Scarlata’s low FODMAP grocery list heavily focuses on whole foods with minimal ingredients despite our country’s minimal data.

Processed foods from country-to-country will differ—and are likely to be the troublemaker—due to their differing quantities and types of ingredients. Even though extensive American FODMAP data is lacking, a dietitian should work with the FODMAPs charts and resources available, scour the ingredients lists of packaged items, and use best judgment when designing a modified FODMAPs plan for an athlete.

The Cumulative Effect of Troublesome FODMAPs

Keep in mind the additive effect of low FODMAP foods—whether that’s within a meal and/or a serving size.

Take a low-polyol item like an avocado, for example. To be considered low-polyol, the serving size is one-eighth of an avocado. Yet if an athlete has a larger serving of guacamole (i.e., the equivalent of half an avocado), it’s now considered a high-polyol item.

Further, an athlete may dice one-eighth of an avocado over an omelet, pair the omelet with blueberries and pineapples, and pour pure maple syrup over a side of protein pancakes. Although these items are all considered low in polyols (minus the eggs and pancake), the additive effects of their individual polyol contents could make this meal troublesome for a polyol-sensitive individual.

As reviewed in part 2 of my FODMAP series, begin a low FODMAPs approach with “low” options without focusing too much on the additive effects of "low" items within snacks and meals—mainly to avoid overwhelming the athlete and developing (or furthering) any negative relationships they may have with food. Alternatively, if the athlete has a known polyol intolerance then only treat a cumulative effect if present.

Image source: Monash App. Depending on the avocado's serving size, its polyol ranking shifts.

What’s Next in my FODMAPs Series?

The last installment, part 4, will cover FODMAPs in sports foods. A go-to message in sports nutrition is to feed athletes “quick carbs” before and during exercise. Yet for a FODMAP-intolerant athlete, feeding them a gel, chew, waffle, or drink that doesn’t comply with their gut could be disastrous.

Further Reading:

This post covers what FODMAPs are, why they can be a problem for some athletes, and why one would follow a low FODMAP diet.

Learn more about where to start and what plan works best for your athlete.

Foods and beverages marketed to athletes contain FODMAP ingredients. Find out what products contain and are free of FODMAPs.

Varney, J., Barrett, J., Scarlata, K., Catsos, P., Gibson, P.R., & Muir, J.G. (2017). FODMAPs: food composition, defining cutoff values and international application. J Gastroenterol Hepatol,32(Suppl 1):53-61. doi: 10.1111/jgh.13698

Review article: Re-challenging FODMAPS

Tuck, C., & Barrett, J. (2017). Re-challenging FODMAPs: the low FODMAP diet phase two. J Gastroenterol Hepatol,32(Suppl 1): 11-15. doi: 10.1111/jgh.13687

Lis, D., Ahuja, K.D.K., Stellingwerff, T., Kitic, C.M., & Fell, J. (2016). Food avoidance in athletes: FODMAP foods on the list. Appl Physiol Nutr Metabl,41(9):1002-1004. doi: 10.1139/apnm-2015-0428

Kate is a leading dietitian and researcher in the area of FODMAPs. Her free resources include a low FODMAPs grocery list and a high- and low-foods list. Follow her on Instagram for FODMAP-friendly recipes and products.

“The Complete Low-FODMAP Diet” by Sue Shepherd, PhD and Peter Gibson, MD.

The book includes lists of low-, medium-, and high-FODMAP options, which is helpful during the challenge and modified diet stages. It also includes a library of recipes and is my go-to book when counseling symptomatic athletes.

The university that penned the term FODMAPs, and continues to lead research on the topic, created an app that allows users to filter by FODMAP subgroup—making it helpful during both the challenge and modified diet stages. The app has a one-time fee and is a tool I use when counseling.

bottom of page