You’ve probably been told at one point or another that fiber is an important part of a healthy diet, but do you know why it’s healthy? (Or what foods it’s commonly found in?) If not, we’re here to help you out.
What Is Fiber?
Dietary fiber is a type of carbohydrate that your body is unable to digest or absorb, and instead stays relatively intact as it passes through your digestive system and out of your body. Fiber is naturally found in many plant foods including fruits, vegetables, legumes, whole grains, nuts, and seeds, and keeps you healthy by helping your body manage hunger, blood sugar, and more.
Fiber is the indigestible part of a carbohydrate that helps pull toxins and cholesterol out of our bodies, promotes good bowel function, slows down digestion, and supports blood sugar levels.
“Fiber is the indigestible part of a carbohydrate that helps pull toxins and cholesterol out of our bodies, promotes good bowel function, slows down digestion, and supports blood sugar levels,” explains Abigail Rapaport, a New York City-based registered dietitian.
There are two types of fiber: soluble and insoluble, and each plays different, yet important, roles in your body. Soluble fiber dissolves in water and can help lower cholesterol and blood sugar levels. Oatmeal, beans, nuts, and apples are all sources of soluble fiber. Insoluble fiber does not dissolve in water but helps move food through your digestive system. Whole grains, carrots, cucumbers, brown rice, and legumes are all healthy food sources of insoluble fiber. Many foods actually contain both soluble and insoluble fiber, though.
“Most whole plant foods contain both types of fiber, and eating a variety of fiber-rich foods will provide you with beneficial amounts of both,” Rapaport says.
How Much Fiber Should You Consume?
The Dietary Guidelines for Americans recommends women consume somewhere around 25 grams of fiber per day, while men should consume around 38 grams of fiber per day. Most Americans consume far less fiber than they’re supposed to, even though fiber is fairly easy to incorporate into a healthy diet.
“While the daily fiber recommendation of 25 to 30 grams per day can seem like an impossible goal, it’s actually not that hard if you add a few roughage-rich foods like avocado, chia seeds or lentils to your day,” says Jenny Champion, a New York City-based registered dietitian.
If you’re looking to include more high-fiber foods into your diet, remember that whole, plant-based foods are typically much better for you than processed foods like high-fiber protein bars and ice cream that have been loaded with added fiber.
“These foods offer significantly more nutrition per bite and there is sufficient research supporting the wide array of health benefits behind intact naturally-occurring fibers,” says Rachel Fine, a registered dietitian and owner of To The Pointe Nutrition.
Here are some ways to incorporate more healthy sources of fiber in your diet:
One serving of chia seeds, which is about two tablespoons (or an ounce), is packed with nearly ten grams of fiber. Chia seeds are also full of protein, antioxidants, omega-3 fatty acids, calcium, magnesium, and other important nutrients. With little taste but a whole lot of texture, it’s easy to sprinkle chia seeds on yogurt, toast, smoothies, and oatmeal, Even better? Combine them with your favorite milk alternative to make chia seed pudding.
Sweet potatoes contain around three or four grams of fiber per 100 gram serving. They’re also packed with vitamins, minerals, and antioxidants. Roast, steam, or boil sweet potatoes for a sweet and easy side that goes well with other foods at any time of the day.
Oats are a high-fiber food, with around eight grams of fiber per cup. Part of what makes oats so healthy is that they contain a high amount of a soluble fiber called beta glucan, which is shown to reduce cholesterol. Researchers believe that as this soluble fiber travels through your digestive system, it dissolves in water, turning into a gel-like substance that binds with cholesterol and carries it from your body.
Not sure how to prepare your oats? Oatmeal and overnight oats are two healthy and easy breakfast options. If you’re feeling more ambitious, toss some oats into your favorite bread or muffin recipe for extra fiber. Registered dietitian Ritanne Duszak says combining foods that are high in fiber, such as oats, raspberries, and chia seeds, can be a great way to meet daily fiber requirements without causing stomach discomfort.
“By cooking oats in milk or water you would also be adding fluid that helps fiber to work effectively and minimize gastrointestinal distress," Duszak says.
“Beans and legumes are a fantastic source of fiber, and are one of my favorites because they also contain filling protein and iron,” says Diana Gariglio-Clelland, a registered dietitian at Balance One Supplements. “A half-cup portion of black beans contains eight grams of fiber.”
Dense in calories and high in fiber, beans are an excellent source of long-lasting fuel, explains Gabby Geerts, a registered dietitian at Green Chef. They also keep you full and keep your digestion regular.
Another powerhouse food, lentils are packed with protein and fiber, while also low in calories and fat. “This makes them a perfect canvas for dish building, working in almost any recipe as a meat substitute in things like stews or tacos,” Geerts says, adding that unlike most beans, lentils don’t require soaking, making them a great option when you need a quick and easy meal.
Lentils contain around 20 grams of fiber per cup.
When it comes to high-fiber foods, pinto beans and other legumes are at the top of the list for registered dietitian Jill Nussinow. “Most people eating beans will eat about one cup, which for pinto beans [is about] 15 grams,” Nussinow says. “This is soluble fiber which helps lower cholesterol and control blood sugar.”
Many people head in the other direction at the mention of split pea soup, but split peas are actually pretty tasty, while also being affordable and packed with lots of important nutrients like B vitamins, folate, and thiamin. If you’re looking for a ton of fiber in a small package, split peas are exactly what you need, containing more than 16 grams of fiber per cup.
“Almonds are a nutritional powerhouse,” Gariglio-Clelland says. In addition to fiber, “They contain heart-healthy monounsaturated fats as well as a good amount of satiating protein,” she says.
Keep almonds in your bag for snacking on the go, or add them to salads, yogurts, and other dishes that could use a bit of a crunch. One serving of almonds (about ¼ cup) contains around three or four grams of fiber.
Artichokes may not be the most commonly eaten vegetable out there, but they pack in a whole lot of fiber—about five grams of fiber per 100 grams. This means a medium-sized artichoke is loaded with about six or seven grams of fiber. There are plenty of ways to enjoy artichokes, but they’re particularly delicious when roasted or steamed and served with a dipping sauce.
“Avocados are high in fiber but have a creamy, satisfying texture that can be used instead of cheese on sandwiches, salads, etc.,” Gariglio-Clelland says. But that’s not all. “Studies show that eating more monounsaturated fats, such as the kind in avocados, may promote heart health,” she says.
In one cup of avocado, you’ll get around 15 grams of fiber, whereas a serving (typically around 50 grams), has somewhere around three or four grams of fiber.
If you’re looking for something crunchy and fiber-dense to have with dinner tonight, broccoli is a good choice. Each cup of broccoli has somewhere around 2.5 grams of fiber, along with lots of other important vitamins and minerals, like potassium, vitamin A, and vitamin C.
Another cruciferous vegetable high in fiber, Brussels sprouts have around four grams of fiber per cup. They’re also a good source of protein, B vitamins, and other important nutrients. Brussels sprouts are delicious when roasted with a bit of olive oil, salt, and pepper.
With around nine grams of fiber per cup, raspberries are a tasty source of fiber that can easily be added to meals or eaten on their own. For a fiber boost at breakfast, add raspberries to oats, cereal, yogurt, or pancakes. They’re also great to snack on in the middle of the day, or when paired with your lunch as a side.
Like raspberries, blackberries pack a ton of fiber into a small, sweet treat, with nearly eight grams of fiber per cup. Mix blackberries with other berries for a fiber-dense fruit salad, or use them to add a touch of sweetness and texture to yogurt or overnight oats.
Quinoa, wheat, barley, oats, sorghum, and spelt are all whole grains—all of which are healthy sources of fiber. Much of the fiber in whole grains is soluble, but whole grains contain insoluble fiber as well, Nussinow says.
100 grams of uncooked quinoa contains about seven grams of fiber, while one cup has around 12 grams of fiber. Mix quinoa with vegetables or beans for a high-fiber lunch or dinner.
Whole Wheat Bread
Non-refined whole wheat bread is an easy way to incorporate fiber into your diet. Whole grains generally contain far more fiber than refined grains, which is why whole grain bread is higher in fiber than white bread and other foods made with refined grains. Each slice usually contains around two to three grams of fiber or more. For a protein-packed breakfast, toast whole wheat bread and top with your favorite nut butter. (However, note that this should be avoided if you have gluten sensitivity.)
“Good news to our gluten free friends, fiber rich grains aren’t just limited to whole wheat,” says Sadé Meeks, a registered dietitian at Freedom Foods. “Fiber rich, gluten free grains include foods like teff, amaranth, buckwheat, quinoa, sorghum, and millet.”