The Best Fiber-Rich Foods And Snacks

Fiber is a nutrient present in plant-based foods, according to Rachel Goodman, a registered dietitian nutritionist based in Brooklyn, New York. Although it’s a carbohydrate, fiber is unique in that “unlike other carbohydrates, it can’t be broken down and digested by the human body and leaves the body relatively intact,” says Goodman.

There are two main kinds of fiber: soluble and insoluble. “Both are beneficial and necessary for optimal health,” she says.

There are important differences between the two types of fiber, notes Sheena Patel Swanner, director of nutrition programs at the American Institute for Cancer Research (AICR). Soluble fiber dissolves in water and turns to a gel in the digestive tract to help slow digestion. Insoluble fiber, on the other hand, doesn’t dissolve in water; instead, it adds bulk to stools to help prevent constipation. Both are important and should be part of your diet, she says.

You’ll generally find both types of fiber together in foods, However, you can find more soluble fiber in foods like oats, beans and fruits, while you typically find more insoluble fiber in foods like vegetables and other whole grains.

Eating a fiber-rich diet has many benefits. Notably, a high-fiber diet can help reduce your risk of cancer, says Swanner. “The latest scientific report from AICR shows that every 10 gram increase in dietary fiber intake is linked with a 7% lower risk of colorectal cancer,” she says. Additionally, the latest AICR report included strong evidence that eating 90 grams (about 3 ounces) of whole grains a day can help reduce colorectal cancer risk by 17%—and eating more may reduce that risk even further^[2]Diet, nutrition, physical activity and colorectal cancer. American Institute for Cancer Research. Accessed 9/30/2021. . A 2020 meta-analysis also found an association between fiber intake and a reduced risk of breast cancer^[3]Farvid MS, Spence ND, Holmes MD, Barnett JB. Fiber consumption and breast cancer incidence: A systematic review and meta-analysis of prospective studies. Cancer. 2020;126:3061-3075. .

Fiber provides many other health benefits as well. “Fiber helps improve and maintain gut health by promoting healthy bacteria growth and strengthening the walls of your digestive tract for optimal function,” says Goodman. “It also helps regulate bowel movements, which keeps your gut healthy, too.”

Goodman notes that including fiber (specifically soluble fiber) in your meals and snacks also helps you feel more full, aids in balancing blood glucose and promotes heart health by helping to lower total and LDL (“bad”) cholesterol.

Indeed, 2020 research suggests that eating plenty of fiber can help reduce one’s risk of heart disease, diabetes and some gastrointestinal disorders^[1]Barber TM, Kabisch S, Pfeiffer AFH, Weickert MO. The Health Benefits of Dietary Fibre. Nutrients. 2020;12(10):3209. . Adequate fiber intake is also associated with lower rates of dyslipidemia, a condition estimated to be associated with more than half the global cases of ischemic heart disease (narrowed arteries that can lead to a heart attack).

To unlock fiber’s cancer-fighting benefits, adults should aim for at least 30 grams of fiber a day, says Swanner. She adds that, on average, U.S. adults need to increase their fiber intake by 12 to 15 grams a day, but don’t let those numbers intimidate you.

Her advice: “Start where you are.” Simply introduce fiber-rich foods into the types of meals and snacks you already eat as a great jumping-off point. Swanner suggests starting the week with Meatless Monday and continuing to add fiber-rich foods throughout the week by tossing berries into your cereal, trading white rice for brown rice and replacing meat with black beans or lentils when preparing chili.

The next time you hit the grocery store, add the following foods to your cart for an extra boost of fiber.

Almonds

Almonds are one of Swanner’s favorite crunchy midday snacks. According to a 2018 metastudy, adding almonds to your diet can help reduce LDL cholesterol (“bad” cholesterol) and maintain HDL cholesterol (“good” cholesterol)^[4]Kalita S, Khandelwal S, Madan J, Pandya H, Sesikeran B, Krishnaswamy K. Almonds and Cardiovascular Health: A Review. Nutrients. 2018;10(4):468. . Swanner recommends adding slivered almonds to quinoa or brown rice to inject your meal with extra nutrients and texture. One ounce, or 23 almonds (a generous handful), provides 3.5 grams of fiber.

Air-Popped Popcorn

Popcorn doesn’t just taste good—it’s also an excellent source of antioxidants, according to research^[5]Coco MG, Vinson JA. Analysis of Popcorn (Zea Mays L. var. Everta) for Antioxidant Capacity and Total Phenolic Content. Antioxidants. 2019;8(1):22. . “I like adding a dash of turmeric, pepper and salt for a fun flavor boost,” says Swanner. Plus, air popping gives you all the nutrients and flavor without necessarily having to add fats like butter. Three cups of air-popped popcorn offers 3.5 grams of fiber.

Avocados

Avocados are a great food to keep around because of their versatility, says Swanner. “You can mash one up with a fork and spread it on toasted whole-grain bread or cut and toss it with cucumbers and tomatoes for a fresh salad,” she says. One medium California avocado contains about 9 grams of fiber.

Broccoli

A great source of fiber, health-promoting antioxidants and cancer-fighting phytochemicals, broccoli packs a big punch. Swanner suggests roasting it in the oven with salt, pepper and olive oil and serving it as a side dish. Chop up any leftovers and throw them into scrambled eggs or on top of homemade pizza. One cup of raw broccoli offers 2 grams of fiber.

Knowing that data supports a high-fiber diet for optimum health and longevity is important, but Goodman notes that focusing on numbers can be stressful for many people. “While it’s good to be aware of fiber sources and amounts, instead of focusing on serving sizes and grams, I recommend a much more sustainable and joyful way to get more fiber.” Simply make an effort to add high-fiber foods into your favorite dishes and notice how your body feels. “If your body is feeling energized, your bowel movements are regular and your blood sugars are balanced, these are all good signs you’re likely getting enough fiber,” she says.

“Too much of anything isn’t good for us,” says Goodman. “Too much fiber, or increasing your fiber intake all at once, can cause constipation, bloat or general digestive discomfort.” If you’re serious about focusing on fiber, she suggests taking a gradual approach and making sure all the food groups are part of your eating plan. “There’s no end-all and be-all to health. Balance is the way to go,” she says.