Why Do Healthy Foods Give Me Gas?

Why Do Healthy Foods Give Me Gas?

By Markham Heid

In my household, for reasons that are obscure even to me, fart is a bad word. At some point, my wife and I must have decided that we didn’t want to hear our kids use the F-word all the time, so we adopted “toot” as a gentler substitute. Beans and other legumes are often on our menu, and things can get pretty toot-y around here.

The medical term for gas is flatus. While gas production varies from person to person, research has found that healthy people “pass flatus” up to 25 times a day. According to a 2013 study in BMJ, a lot of plant-based foods—legumes in particular, but also whole grains, some fruits, and many vegetables—are common gas triggers.

Why is this so? Fiber is the part of plant foods that your gut can’t absorb. It passes through the gut tract relatively intact—improving the healthy flow and absorption of other food molecules—until it reaches the colon, which is where the bulk of your gut’s bacteria live.

The majority of these bacteria feed on fiber, and one of the byproducts of this feeding is gas. The bacteria that break down fiber also produce a number of metabolites, including short-chain fatty acids (SCFA), which turn down gut inflammation and do other good work for us. Butyrate, for example, supports the health of the epithelial cells that form the gut’s protective lining. Fiber is also considered a prebiotic because it encourages the proliferation of healthy gut bacteria.

Despite all of these benefits, some people purposely avoid fiber-rich foods—especially legumes—in order to dodge gas. This is a problem. According to nutrition resources from the University of California, San Francisco, the average American only gets about 15 g of fiber each day, while national diet guidelines encourage intakes in the range of 25 to 30 g. Some experts have speculated that fiber-deficient diets may be contributing to the rise of inflammatory bowel disease (IBD) and could also be a factor in type-2 diabetes and other metabolic conditions.

It’s important to note that, for people who have digestive health issues, beans and other fibrous plant foods can in some cases exacerbate gut symptoms. For these people, eating large amounts of these foods may only cause more trouble.

But for everyone else, fiber-rich foods—despite any gas they may cause—are an important and healthy addition to one’s diet. And, in many cases, the more of these foods you eat, the more your gut may adapt to them in ways that reduce your gas production.

Gas can be embarrassing. But a little extra tooting shouldn’t dissuade anyone from eating more healthy foods.


Markham Heid is a freelance health writer. His work has appeared in TIME magazine, The New York Times, and elsewhere. He’s a regular contributor at Elemental, a Medium publication, where an alternative version of this story first appeared.