Does Fiber Make You Gassy? This Could Be Why

This article contains additional reporting by Jennifer Chesak.

Fiber is a good-for you nutrient that can help support your hormones, manage your cholesterol, and keep your gut happy. But does fiber make you gassy?

The short answer is that it can. But if fiber seems to be the culprit of your digestive issues, don’t quit it all together.

Instead, do some detective work to find out if you have an underlying concern that could be causing discomfort. According to Marie Carlson, a nurse practitioner formerly with Parsley Health, several reasons could be to blame.

Symptoms to watch for with fiber

If you’re dealing with any of the following symptoms after eating more fiber, something could be up.

• gas
• bloating
• feeling uncomfortably full after eating
• diarrhea
• constipation
• belching
• acid reflux
• abdominal pain or cramping

Why does fiber make you gassy?

Here are some of the top reasons fiber might leave you feeling less than great.

Eating too much fiber

Going much higher than daily fiber recommendations or increasing fiber intake too fast can lead to symptoms.

Some sources recommend a daily fiber intake of 19 to 38 grams per day, depending on your age and sex. Most groups, from the American Heart Association to the FDA, recommend about 28 grams per day.

“But it looks like going up to about 50 grams a day may be ideal,” Carlson says.

Increasing fiber intake immediately

Increasing fiber can generally be beneficial for your health, but adding too much too quickly might make you uncomfortable. “Your digestive system has to adjust to the new fiber intake,” Carlson says.

She recommends increasing your fiber consumption gradually, adding about 2 to 3 grams per day. That equates to an additional serving of fruits, vegetables, or whole grains.

For someone who finds they’re more sensitive to changes in fiber intake, Carlson recommends adding one serving every two or three days.

Not drinking enough water

If you start eating more fiber but aren’t getting enough fluids, you could experience bloating and gas.

Fruits and veggies naturally contain water, which can help. But if you're eating grains, you may need to boost your hydration.

Also, if you’re taking a fiber supplement, drink it with a tall glass of water, Carlson says.

FODMAP sensitivity

“FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, which are basically types of fiber that are either slowly absorbed or indigestible in our systems,” Carlson explains.

FODMAPs are in a lot of foods, but some key FODMAP-containing items include wheat, milk, cauliflower, onions, apples, and legumes.

“A lot of people who have IBS find relief by going on a low-FODMAP diet,” Carlson says.

So if you increase your fiber intake and you have undiagnosed irritable bowel syndrome, the increase in FODMAPs, along with the extra fiber overall, could be making you feel crummy. 

Trying out a low-FODMAP diet might be a solution, but Carlson also recommends testing for small intestinal bacterial overgrowth (SIBO).

“If you have SIBO, that really needs to be identified and treated before you can tolerate FODMAPs,” she says.

Lectin sensitivity

“Lectins are a type of carbohydrate-binding protein, and they’re found in high levels in certain grains, legumes, and nightshade vegetables,” Carlson says. They’re also found in smaller amounts in most types of plant foods.

Lectins seem to have some good effects and some bad ones. Ultimately, we need more research on whether lectins are a dietary concern.

But some people may be particularly sensitive to lectins. So this could be another reason you’re dealing with digestive issues when eating more high-fiber foods, many of which are higher in lectins.

Gut motility issues

The muscles in your GI tract are responsible for moving food and waste along. This is called gut motility. If your gut is sluggish, fiber may cause bloating and discomfort.

“Slow gut motility is really common in people with diabetes, hypothyroidism, and even people with high-stress levels,” Carlson says. IBS and SIBO can also mess with gut motility.

Allergy and/or sensitivity to wheat

“One common recommendation to increase fiber is to add to your whole grain intake," Carlson says. "Many people will just turn to whole wheat products.”

But wheat is a common trigger of GI symptoms through many pathways: celiac disease, non-celiac gluten sensitivity, FODMAP sensitivity, and lectin sensitivity.

So for some people, loading up on more wheat products than usual will send their digestive system into a tailspin.

But don’t ditch fiber

If you’re experiencing symptoms from eating fiber, aim to get to the root cause, rather than giving up on the nutrient completely. Fiber has benefits.

“Fiber generally promotes digestive health and helps balance blood sugar and cholesterol levels,” Carlson says. “And it’s actually the primary food source for the trillions of microorganisms that are living in our intestines, known as our microbiome.”

Fiber also helps you feel fuller longer, which can be a benefit for weight management.

Good fiber intake has also been shown to reduce the risk of colon cancer. And one review of existing studies found an association between higher fiber intake and reduced risk of death from all causes.

The researchers also found that the consumption of fiber from nuts, seeds, and legumes reduced risk of cardiovascular-related deaths by more than 40 percent.

How to determine the right fiber intake

Get fiber from whole food sources

When possible, opt for whole foods over fiber supplements to avoid symptoms, Carlson recommends.

Ideally, you want to mix it up with fiber your sources too. “I tend to steer people towards nuts, seeds, fruits, veggies, beans, and legumes,” she says.

Choose the right supplements

If you suspect FODMAPs or lectins might be an issue, you may need to try a fiber supplement.

Carlson recommends acacia, psyllium husk, or sun fiber. Working with a Parsley provider can help you determine the right dose for you to prevent symptoms.

Give yourself enough time between meals

To allow for optimal gut motility, Carlson suggests a 12-hour fast overnight (from 8 p.m. to 8 a.m., for example) and allowing about three to four hours between each meal.

FAQ

How long does fiber bloating last?

How long you might experience bloating will depend on what you ate, how much, and whether you're already experiencing bloating and constipation. If fiber-related bloating doesn't resolve in a few days, talk to your doctor.

How do I stop fiber from giving me gas?

If fiber is frequently making you uncomfortable, you may have an underlying condition that needs to be treated or a food sensitivity to address. Ways to help prevent fiber from giving you gas include increasing your fiber intake slowly and drinking more water.

Does too much fiber make you fart a lot?

Experiencing a little gas from fiber is normal. However, if fiber makes you excessively gassy, you may have an underlying condition that needs to be treated or a food sensitivity to address.

What are the symptoms of too much fiber?

Too much fiber may cause gas, bloating, diarrhea, constipation, abdominal cramps, feeling extra full, belching, or acid reflux.

Does fiber make you lose weight?

Fiber makes you feel fuller longer, helps control blood sugar, and feeds the good bacteria in your gut. All these factors can help with weight management.

Does your body get used to fiber?

Most people will get used to an increased fiber intake over time. If your body continues to react to fiber after increasing your consumption slowly, you may wish to talk to your doctor to see if you have food sensitivities or an underlying condition.

Takeaway

At Parsley Health, members work with a provider to help them optimize their diet and lifestyle. Having support can be a game changer for adjusting your nutrition to relieve digestive symptoms.

If you’ve increased fiber gradually, are following the guidance above, and are still having symptoms, that’s a sign to check in with your health care provider for further evaluation and testing.