Fiber foods

10 of the Best High Fiber Foods You Should Add to Your Diet

If you’ve heard of fiber, you’ve probably heard that it’s a nutrient that fills you up and sends you to the toilet. But what you might not know is that most Americans (runners included!) don’t get enough fiber in their diets. This is a problem not only for your gut, but also for your overall health and performance.

We spoke to two dietitians and did some in-depth research to find out exactly what fiber is, why it’s so important, and how runners can incorporate high-fiber foods into their diets without disrupting their training.

What is fiber?

All of the delicious, energy-boosting fruits and vegetables we love contain carbs, and fiber is one of them. Fiber is a type of carbohydrate which plays a role in maintaining overall health and comes in three different forms: soluble, insoluble and functional. Each type plays a different role in keeping you healthy.

“Soluble fiber is the type that dissolves in liquid and includes the liquid in our stomach and gastrointestinal tract,” Kelly Jones MS, RD, CSSD, Sports Dietitian and Professor of Nutrition and Exercise at Bucks County Community College says The runner’s world. When soluble fiber dissolves, it forms a gel-like texture that helps your body absorb other nutrients and slows digestion, she says.

Insoluble fiber is the opposite. Kristin Kabay, MS, RD, CSSD, sports dietitian and marathon runner explains: “they don’t dissolve in water. They act like a broom of sorts, combing through your intestines and sweeping everything away. This type of fiber is the one that removes toxins from your body, regulates bowel movements and prevents constipation.

Finally, functional fibers are supplements added to packaged foods by manufacturers that may help some people increase their fiber intake, Kabay says. You can spot some of these additive ingredients, like soluble corn fiber or enriched wheat flour, on the nutrition label of some packaged foods.

Eating foods loaded with functional fiber, especially if you have a sensitive digestive tract, can cause constipation or bloating, Jones says. “If you see one type of fiber added to a product and you don’t see other whole plant foods on your ingredient list, then you know it could be a fiber type overload that can have an impact on your digestive health,” she adds.

Luckily, fruits and vegetables are high in both soluble and insoluble fiber, Kabay says, so you don’t have to track how much of each fiber you eat.

Why is fiber so important?

Eat the right amount of fiber each day – 31 grams for men and 25 grams for women according to the USDA– can produce a ton of different health benefits. The main reason fiber is so important, Kabay says, is because it can be incredibly beneficial for so many different organ systems in the body, including your gut and your heart.

Research confirms the many benefits of fiber. To begin with, a recent study published in the journal American Society for Microbiology found an association between a high-fiber diet and fewer antibiotic-resistant microbes in the gut. This shows that fiber can help fight antibiotic resistance, which prevents bacteria, viruses and fungi from responding effectively to antibiotics.

When it comes to heart health, a recent prospective study published in the journal Nutrients found eating natural sources of dietary fiber such as legumes, fruits, vegetables and nuts was protective against cardiovascular disease. In addition, a meta-analysis published in the Diabetes Survey Journal linked higher fiber intake to a lower risk of type 2 diabetes emphasizing the protective effects of berries, green leafy vegetables, yellow vegetables and cruciferous vegetables.

Plus, according to Kabay, increasing your fiber intake can help reduce cholesterol and blood sugar levels, as well as lowering your risk of Colon Cancer. Additionally, Jones points out to research which shows that increasing your fiber intake can improve your mental health.

What happens if you don’t eat enough fiber?

If you’re not eating enough fiber in your diet, Jones says, you may experience the following symptoms:

  • Irregular stools
  • Constipation and digestive disorders
  • Poor gut health, which can impact immune function, metabolism, and even mental health
  • High blood cholesterol
  • Blood sugar fluctuations
  • Lack of satiety after eating

    How to include more fiber in your diet

    While it might seem like adding a bunch of fiber-rich foods to your diet at once would be the easiest way to boost your fiber intake, it’s probably not the smartest.

    Jones says eating too much fiber at once can cause digestive issues. To avoid this, gradually increase the amount of fiber you eat each day and focus on eating the fruits and vegetables you like the most.

    As a runner, it’s all about timing. Kabay suggests saving high-fiber foods for a post-race meal or snack to avoid discomfort or an unplanned pit stop on the road. Practice eating foods with fiber before a race if you plan to eat them on race day.

    Having a more sensitive digestive tract doesn’t mean you have to completely avoid high-fiber foods, Jones says, even if you’ve been diagnosed with irritable bowel syndrome. Instead, just be aware of what you eat while running and see how your body reacts to different foods.

    Top 10 High Fiber Foods to Add to Your Diet

    You won’t be able to dramatically increase your fiber intake overnight. However, you can slowly incorporate high-fiber foods, like the ones on this list, to make sure you’re getting enough fiber.

    *Fiber numbers based on USDA FoodData Central

    1. Artichoke

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    A medium-sized artichoke contains about 7 grams of fiber. There are a ton of different ways to introduce this vegetable into your diet. You can pair it with spinach for a tasty snack or add it as a pizza topping.

    2. Classic oats

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    Jones says the best thing about classic oats is that you can enjoy it anytime — a sweet bowl for breakfast or a savory one for dinner. Plus, just a 1/2 cup serving contains 4 grams of fiber. Top it with fruit and you’ll have even more.

    3. Pumpkin

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    A single cup contains 7 grams of fiber. For breakfast, you can mix this vegetable with your oatmeal or make a batch of pumpkin muffins.

    4. Prunes

    high fiber foods

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    If you’re looking for a quick fix to your digestive issues, you’ve probably reached out for prunes or prune juice for help, since a quarter cup contains about 3 grams of fiber. It’s a great snack for those who struggle with constipation while traveling. Pack this fruit with water to snack on during your trip. Jones says this will help move things along a little easier.

    5. Raspberries

    high fiber foods

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    Raspberries are one of the most fiber-rich fruits you can find, containing 8 grams per cup. There are a ton of different ways to add them to your diet, whether you mix them into yogurt, a smoothie, oatmeal, or just munch on them for a snack.

    6. Blueberries

    high fiber foods

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    A cup of blueberries contains about 4 grams of fiber. Make blueberry muffins, add them to smoothies, or simply eat them as a snack with other berries. Plus, they’re packed with tons of antioxidants your body needs to fight free radicals and stay healthy.

    7. Lawyer

    high fiber foods

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    Add avocado to salads, make guac, or spread it on whole-wheat toast. Half of a medium sized avocado contains 7 grams of fiber.

    8. Medjool dates

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    There are a wide variety of dates, but Medjool dates are a little milder and sweeter, says Kabay. Just two dates will provide you with 3 grams of fiber. Take them along for some fuel on longer runs or keep them as a post-race snack.

    9. Almonds

    high fiber foods

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    You don’t have to go crazy with this snack, just one ounce of almonds (about 23 in total) contains nearly 4 grams of fiber. Toss them in trail mix with dried fruit for healthy carbs, protein, and fats in one snack.

    10. Lentils

    high fiber foods

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    Jones says lentils are great for runners because they come in a ton of different varieties: red, green, brown, and yellow. A cup of cooked lentils contains over 15 grams of fiber, and they’re also high in iron and protein.

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