How to Deal With Food Intolerances That Can Mess With Your Fuel Plan

Gluten is the protein in grains that helps bind together runner staples like breads, bagels, pastas, and oats. Gluten-free versions of all these foods are readily available, but that doesn't necessarily mean you should just trade in all your favorite foods for their gluten-free versions. If you have a gluten intolerance, Bonci recommends finding swaps for certain foods—like trying zucchini noodles in place of pasta—and using gluten-free versions as needed because GF versions can be more expensive. Plus, a discriminating palate will usually be able to tell the difference. And when you remove the gluten from certain foods, you can also lose some of the protein. To sidestep this issue, Bonci suggests carb sources that are naturally gluten-free—like rice, potatoes, millet, and quinoa—and reaching for corn, rice, and even bean-based pastas and cereals based on personal preference.

Whether you have an allergy, intolerance, or sensitivity to gluten will also play a role in what ends up in your grocery cart. Individuals with celiac disease, an autoimmune disorder, need to eliminate gluten from their diets entirely because it causes damage to the small intestines. Gluten is off the table, period. But if someone is intolerant, they may have some wiggle room. "If someone has a gluten intolerance, they can experience digestive problems, but there is no damage to the intestine," Bonci says. They may choose to cut out it out entirely, or limit their consumption based on what they can tolerate. The third possibility is a non-celiac wheat sensitivity. In this case, individuals can have any glutinous foods—like rye, barley, and oats—but not wheat. Depending on their symptoms, individuals may scale back on wheat or nix it all together.

After gluten, dairy is the second most common culprit for digestive issues among runners. Lactose, the naturally occurring sugar in dairy products, falls under the "D" in the FODMAP acronym—Fermentable Oligo-,Di-, Mono-saccharides, and Polyols. FODMAPs are poorly absorbed short chain carbohydrates, which means that they pull extra water into the small intestines during digestion, which can then cause issues like bloating, gas, diarrhea, and constipation. A high-FODMAP food is more likely to cause these problems.

Sidestepping a lactose intolerance can be as easy as taking a lactase pill or drops, which contain the enzyme responsible for breaking down the sugar. Or, lactose-free versions of most dairy products are an easy and inexpensive swap. Plus, many people with a lactose-intolerance can still tolerate many yogurts due to its live and active cultures and aged cheeses that are naturally low in lactose. However, Bonci does caution runners from switching over to plant-based products (like almond and coconut milks) entirely. "The majority of plant-based milks are pretty low in protein, with the exception of pea, peanut, and soy," she says. "Nutritionally, they just don't compare to dairy milk, and they also come at a higher price point."

Believe it or not, the simple sugar found in fruits and vegetables is also a FODMAP. Runners who opt for a pre-run apple or watermelon slice, which are especially high in fructose, may be surprised to find them as the cause of their digestive problems. Bananas, clementines, oranges, strawberries, and even papaya are safer options before a morning run.

But even small things like swapping sugar for a drizzle of honey or agave in your morning oatmeal can derail digestion a few miles down the road. While these natural sugars provide a quick punch of energy, they are high in fructose. Bonci recommends maple syrup or stevia instead if you're finicky to fruit sugars.

In situations like these, in which runners are blindsided by what's causing an upset, many think they simply can't tolerate food before a run and just skip their pre-run meal. This is almost always the wrong move. Bonci says this is why finding the right substitutes for problematic foods becomes especially important.

"The big thing that I aways talk to my runners about is it's not just what you take off the plate, it's what you put there instead," she says. "Runners need to be fueled, and we don't want them running on empty."

These tiny fungi help bread rise, so they'll crop up in the obvious places like bagels, rolls, and muffins. But you'll also find them in your post-race beer. This doesn't mean you need to cut out your favorite pint but adjust based on your symptoms.

"A lot of food sensitivities are volume-related," says Bonci. "So when people work on changing the amount of a problem food rather than cutting it out entirely, they have a much broader base of foods to choose from. It's so much nicer to be able to include the foods that you like rather than live in the 'Land of No' all the time."

Avoiding yeast can be as simple as checking ingredient labels, or opting for an unleavened alternative. Pitas, tortillas, crackers, and pasta are great carb sources without yeast (but you will have to double-check for gluten if that also bothers you). Rice-based crackers and cereals are also good options.

The protein found in the egg yolk and white is a common allergy and can be one of the reasons your runs aren't turning sunny-side up. Eggs may be in foods you least expect."It really requires being hyper-vigilant about label-reading," says Bonci. When you're looking for a post-long run treat, an easy way to skip the egg is to look for items labeled "vegan."

That cup of coffee gets you moving on race morning in more ways than one. But when it comes to caffeine-related digestive distress, Bonci says there are a few things to consider. Be aware of how much you consume, and if you do get your caffeine kick from coffee, be wary of what you are mixing in. For example, if you're adding a dairy creamer or an alcohol-based sweetener (like erythritol), those could be the culprit rather than the caffeine. Waiting a few minutes to run after you drink your cup of joe can let your stomach settle and give you some time to fit in a bathroom break.

However, some individuals do have a hypersensitivity to caffeine, which can cause headaches, racing heartbeat, and nervousness (above and beyond the usual pre-race jitters). If you count yourself among the caffeine-sensitive—or you just prefer decaf—sipping on any hot beverage can have a laxative effect to get your system moving in the morning without the added stress.

Runners frequently turn to these artificial sweeteners when looking to shave calories or sugar from their diets. Another type of FODMAP, sugar alcohols can show up in nearly any food product labeled "sugar-free" or "no sugar added," so you'll need to check the ingredient list. Xylitol, mannitol, and erythritol are just a few aliases to look out for. Sugar-free gum and mints can be especially high in this category, so steer clear if you know you're sensitive. And if you really need a low-calorie sweetener, try plant-based stevia.

While food intolerances can be irritating, they don't have to sabotage your race. Some extra vigilance and a few tweaks to your diet can get you from start to finish line confidently, knowing there won't be any unwelcome stops in-between.

"Everybody keeps a log of their miles, so if you're having digestive issues, keep a log of your foods and symptoms," Bonci suggests. "That's how you can be your own detective and determine what works and what doesn't."