If you had to give an award to “World’s Sexiest Nutrient,” I’m not sure what would win, but it probably wouldn’t be fiber. Especially soluble fiber. But TBH that’s pretty unfair of us. Fiber offers your body a ton of health benefits (reduced risk of chronic disease, boosted metabolism, reduced inflammation, and better heart and gut health), and unlike protein, you’re probably not eating enough of it.
There are two types of fiber: insoluble and soluble. Insoluble is pretty much the roughage from fruits and veggies that sweeps out your insides and bulks up your stools for regular BMs. On the other hand, “soluble fiber gets its name because it is soluble in water,” says Marjorie Nolan Cohn, RDN, founder and owner of MNC Nutrition, LLC in Philadelphia and spokesperson for the Academy of Nutrition and Dietetics.
Basically, soluble fiber absorbs water, swells, and creates a gel-like substance during digestion, Nolan Cohn says. That keeps BMs moving, but it also has another power: to keep your heart healthy. “Along with water, the gel-like structure can also absorb fatty acids, so it has an added benefit of reducing cholesterol,” she says.
Soluble fiber is also useful in slowing digestion, something that helps regulate blood sugar levels, says Nolan Cohn. A stable release of glucose into your blood helps prevent blood sugar dips and spikes that trigger hunger and mess with the hormones that play a role in appetite control. Finally, like all fiber, soluble feeds your GI bacteria, and we’re all about a healthy gut these days.
What are the best foods high in soluble fiber?
Here’s the thing: Fiber-rich foods are going to include both insoluble and soluble fiber—some simply have more of one and less of the other. Don’t stress too much about specific soluble fiber counts; it’s difficult to tell how much soluble fiber specifically is in foods since nutrition labels usually just include total fiber. Aim for 25 grams of total fiber a day, says Nolan Cohn, and you’ll be good.
However, if you want to hedge your bets and ensure you’re getting lots of soluble fiber in the mix, here’s a list of high-fiber foods that generally have a decent amount of soluble fiber, too:
Fiber: 4 grams per cup (cooked)
There’s a reason why “reduces cholesterol” or “is good for heart health” is slapped on oatmeal labels: the cereal contains a type of soluble fiber called beta glucan, which is what gives it its creamy consistency.
2. Black Beans
Fiber: 17 grams per cup
No matter what type of bean you love best, they’re all winners here. But black beans win out, says Nolan Cohn. “One cup of black beans has five grams of soluble fiber—that’s a lot,” she says. Others that get close are navy, red, and kidney beans.
Fiber: 16 grams per cup (cooked)
If you don’t routinely eat lentils, you’re missing out. Not only are they the perfect source of protein in those grain and veggie bowls you’ve been loving on lately (you know, the ones with the to-die tahini sauce), but they’re also packed with soluble fiber, says Nolan Cohn.
Fiber: 10 grams per 1-oz serving
Chia seeds are little fiber bombs. One tip-off that it contains soluble fiber: when mixed with liquid, chia takes on the gel-like texture that makes it so excellent in chia puddings.
Fiber: 3 grams per tablespoon
Plant-based bakers know that by mixing water with ground flax, you can make a “flax egg.” That’s soluble fiber at work, folks. (Oh, BTW, if you’re on the keto diet, know that the tablespoon has 3 grams of carbs and 3 grams of fiber. That means 0 net carbs—making flaxseed a good way to get more fiber into a diet where fiber may be lacking.)
Fiber: 6 grams per cup (cooked)
7. Brussels sprouts
Fiber: 3 grams per cup (raw)
The veggie joins others like broccoli and cabbage as good sources of fiber. If you’re not into the whole ordeal of chopping up your sprouts, buy pre-shredded bags of the veggie to sauté, throw on a pizza, or toss with olive oil and roast.
How can I add more soluble fiber (and fiber in general) to my diet?
Right. The goal may be 25 grams, but most people are getting only half of that amount. That’s a big reason why nutrition experts tell you to fill half your plate with veggies (and fruits) and one-quarter with whole grains—these are all top-notch sources of fiber, and eating this way will help you reach that goal.
If you regularly say things like “I’m just not into vegetables” or “I’m trying to avoid grains,” then you may run low. If you’re really unsure, hook up with a registered dietitian to assess your needs. They may recommend a psyllium husk supplement (a supercharged source of fiber). It often comes in powder form, which you can then stir into yogurt or hot cereal or add to your smoothie to make it more palatable, says Nolan Cohn.
No matter what fiber source you’re going for, the trick is to gradually—one more time for those in the back—gradually increase consumption. “If your body isn’t used to it, increasing fiber intake quickly can lead to GI distress,” Nolan Cohn says. Her recommendation: Don’t add more than three to five grams of fiber per meal to start; two to three grams per meal is on the safer side. Here’s to a happy heart and stomach.