My fellow vegans, raise your hands if you’ve been asked this question: “Where do you get your protein?” Everyone else, just picture a stadium full of wildly waving arms.

Many people still picture vegans as malnourished waifs that must be missing out on something, no matter how many vegan athletes there are or how many times we point out that half a cup of beans has as much protein as an ounce of meat.

There are some nutrients vegans should watch, but it’s not so often we talk about what omnivores might be missing. It turns out that those beans (and almost all plant foods) contain something that’s sorely lacking in the average American diet. So, now that the tables have turned, let me ask you: where do you get your fiber?

Fiber is found only in plants, as part of what makes them fibrous, crunchy, or in the case of oatmeal, gummy. Even if animals eat plants, fiber isn’t found in their meat. This means that people who eat a lot of animal products, and eat vegetables as an occasional side dish, may not be getting enough.

How much is enough? 25–38 grams per day for most adults, according to the USDA. How much does the average American eat? About 16 grams.

It’s not a problem for vegans, though, as most eat more than 40 grams each day, thanks to a plant-filled diet that’s often high in fruits, vegetables, whole grains, and our friend the bean. Can vegans also struggle to get enough fiber? Absolutely, but those who eat whole grains and legumes will find it difficult to get too little fiber.

What’s the problem with not getting enough fiber? There are different kinds of fiber, but generally speaking, meeting the dietary fiber recommendation can lower your risk of heart disease, type 2 diabetes, and colon cancer. Soluble fibers, like those in oatmeal, can keep you full longer while helping you digest your meal more slowly, keeping your blood sugar from spiking too quickly. Some fibers are also food for the healthy bacteria in your gut.

One of the best reasons to get fiber is a little more sensitive, though: it helps prevent constipation and keep you regular, which is why grandma drinks prune juice (side note: no ageist stigma can keep me from my love of prunes).