Does Fiber Make You Gassy?
If so, you're not alone! But you need not suffer in (lack of) silence. Here's how to inch closer to your fiber goals for the day without passing gas from morning to night.
Reviewed by Dietitian Jessica Ball, M.S., RD
Having gas stinks; often literally. But it's something that everyone deals with, and at a far more frequent rate than you might imagine. The average person passes gas about 14 times per day, Johns Hopkins Medicine experts estimate. Gas can be the result of swallowing too much air (while sipping on something fizzy, chewing gum or eating too quickly). It can also be triggered by the way our gut microbiome interacts with the food we eat, according to the National Institute of Diabetes and Digestive and Kidney Diseases.
In rare cases, conditions like irritable bowel syndrome (IBS), food intolerances, constipation and small intestinal bacterial overgrowth (SIBO) can contribute to your overall gas production, so if you think that something else might be "off," check in with your doctor. But the vast majority of the time, it's a symptom that relates to the fact that a whopping 95% of American adults don't consume enough fiber on a regular basis. Then when we do (or even inch ever closer to our fiber quota), our guts can revolt. The result? Gas.
Related: 6 Sneaky Signs You're Not Eating Enough Fiber, According to a Dietitian
Why Do We Need Fiber, Anyway? A Refresher on the Health Benefits of Fiber
"Fiber is a type of carbohydrate found in plant-based foods that our bodies cannot fully digest or absorb," explains Kenneth Brown, M.D., a gastroenterologist in Plano, Texas, and the host of the Gut Check Project podcast. "Instead, fiber travels through the digestive system intact, providing various health benefits along the way."
There are two main types of fiber:
Soluble fiber dissolves in water, forming a gel-like substance in the digestive tract. "It's less likely to cause gas production than insoluble fiber for most people," Brown says. You'll find soluble fiber in oatmeal, beans, lentils and some fruits and vegetables.
Insoluble fiber does not dissolve in water, and instead adds bulk to the stool. "It can sometimes cause more gas in people with dysbiosis [an imbalanced, less-healthy gut microbiome] since it does not form the gel-like matrix of soluble fiber but arrives in the colon intact," Brown adds. Insoluble fiber comes tucked inside nuts, seeds and skins of fruits and vegetables.
A bit of gas is a small price to pay for the many health benefits of fiber. Cynthia Sass, M.P.H., M.A., RD, CSSD, a board-certified sports dietitian in private practice in Los Angeles, specializing in plant-based performance nutrition, gives us the myriad reasons why we should eat more fiber:
Promotes fullness, which supports weight management
Aids in the regulation of blood sugar and insulin levels
Plays a role in overall digestive health and bowel regularity
Fosters a healthy gut microbiome, which is linked to immunity, anti-inflammation and mood
Supports high-quality sleep
Helps reduce blood cholesterol to fend off heart disease
Lowers the risk of certain cancers and type 2 diabetes
Why Fiber Might Make You Gassy
As you can see, fiber is an important nutrient that plays a crucial role in maintaining good digestive (and overall) health, but fiber—especially of the insoluble variety—can also cause gas and bloating in some individuals.
"When gut bacteria break down and ferment fiber, gas is created as a byproduct," Sass says, including hydrogen, methane and carbon dioxide. "That gas can build up in your digestive tract like air inflating a balloon, causing bloating and flatulence."
When our gut microbiome is thriving, fiber is digested by our gut bacteria, leading to small amounts of gas and the production of beneficial metabolites, such as short-chain fatty acids, Brown explains.
"However, in a gut with an imbalance of good to bad bacteria, certain types of bacteria may dominate over others, causing them to produce more gas when they break down fiber. This increase in gas can lead to discomfort," he adds.
Related: Why Bloating Can Be Normal and Healthy, According to a Dietitian
8 Tips for How to Eat More Fiber and Experience Less Gas
Yes, it is possible to eat too much fiber, and one of the downstream effects of that can be gas and bloating. That being said, most of us are currently falling significantly short of our Rx (Americans eat 15 grams per day on average, compared to the recommended 25 to 31 grams recommended by the 2020-2025 Dietary Guidelines for Americans).
So to get closer to your fiber targets for the day—without having gas all day—try these tips from Sass and Brown.
Take your time. Gradually increase your fiber intake over several weeks or months, Brown says. (These 12 high-fiber foods are a good place to start!) Sass suggests thinking of eating fiber like exercise for your digestive tract: "Like any muscle that experiences an increased workload, your GI tract needs to adapt, so it's important not to overload it with too much additional fiber all at once," she says. "Going from eating 10 to 15 grams per day to 50 grams overnight is like going from being inactive to running 5 miles—it's too much too fast."
Keep a journal. To know where you're starting, how much more fiber to shoot for, plus what else might be impacting your gas and bloating levels, Sass advises clients to use a tracking tool for a short-term basis (she likes My Fitness Pal) to get a baseline. "Journaling may help you notice some patterns," Sass says, especially when you take note of what, when and how much you eat and drink as well as your physical activity level, and compare them to your symptoms.
Choose wisely. As you ease into eating more fiber, you may want to fill your plate with some of the more easily digestible options. "Cooked vegetables, fruits without skins or seeds, and cooked whole grains are foods that are less likely to cause gas," Brown says.
Stay hydrated. It's crucial to consume plenty of H2O along with fiber to help the fiber move through your system, Sass says. "If you don't drink enough water, the fiber can become dry and compact, leading to more gas and constipation," Brown adds. Here's how much water you should try to drink per day, according to dietitians.
Move your body. If you can tell the gas is just sitting there waiting to be released (ahem, bloating!), Sass promotes taking post-meal walks, which can help your body release gas.
Try tea. Sipping on peppermint tea may also help ease indigestion and gas, Sass adds.
Pop a probiotic. "You can improve your microbial diversity by supplementing it with a probiotic that has been shown to survive to the colon, like a spore-based one," Brown says. Check out what to look for on the label to choose the best probiotic supplement.
Ask a registered dietitian if you should consider an elimination diet. Eliminating certain foods from your diet for a period of time can help you identify food intolerances or sensitivities that may be causing excessive gas, Brown explains. "Lactose, gluten and FODMAPs are common culprits." If you get the green light from a dietitian that it might be a good idea for you, ask them for a custom menu or try our elimination diet meal plan.
The Bottom Line
If you experience an uptick in gas after eating a fiber-rich recipe, you're not alone. To tame your tummy as you score all the health benefits of fiber, take your time adding more fiber to your diet, add a probiotic to your daily routine, keep a journal to note any symptom triggers, drink water early and often throughout the day, and lace up your shoes for a post-meal walk.
"If you're stumped after taking all of these steps, talk with your health care provider or consider meeting with a registered dietitian who can tailor a plan based on your needs and goals," Sass says.
