Improving fiber intake should be a top priority for many of us. But fiber doesn’t need to be a stir-in fiber supplement from the local drugstore. Many of the healthiest diets naturally include fiber – except the carnivore diet, of course. It’s just a matter of knowing which foods are high in fiber and when to include them. Here’s what you should know about high-fiber foods.
What is Dietary Fiber?
Dietary fiber is the part of plant foods that passes through the digestive system, more or less intact. It’s a carbohydrate in fruits, vegetables, grains, nuts, seeds, and legumes. Unlike other carbs, fiber doesn’t easily break down into sugar molecules. So, it doesn’t provide calories or energy to the body. There are two main types of fiber: Soluble and Insoluble.
Soluble fiber dissolves in water, forming a gel-like substance in the digestive tract. It’s known for helping to balance cholesterol and blood sugar levels. Examples of foods high in soluble fiber are oats, legumes, and root crops like carrots and sweet potatoes. You’ll also find it in certain fruits (apples, citrus, and strawberries) and cruciferous vegetables.
Insoluble fiber doesn’t dissolve in water. Instead, it adds bulk to the stool. That extra bulk can aid in regular bowel movements and may ease constipation. Examples of foods high in insoluble fiber are whole grains, leafy greens, cruciferous vegetables, and nuts. It’s also found in fruits, especially when eaten with the skins intact.
You’ll notice cruciferous vegetables have both soluble and insoluble fiber. One isn’t more important than the other. Including both types of fiber promotes a healthy digestive tract, ultimately affecting whole body health.
How Much Fiber Do We Really Need?
The recommended daily fiber intake varies by age and gender. But it generally falls between 25 and 38 grams daily for adults. Of course, individual needs may vary based on activity level and overall health. The Academy of Nutrition and Dietetics recommends getting about 14 grams of fiber for every 1,000 calories a day.
Most Americans don’t get enough fiber in their diets. The modern emphasis on boxed and processed foods means we’re not getting enough whole foods. As a result, Americans are getting only about half the fiber they should.
If you don’t want to be part of that statistic, be sure to increase your fiber gradually. You don’t want to get up one day and decide to eat a high-fiber diet. Your digestive system may not be ready for that. It’s also important to get enough water (away from meals) to help avoid digestive discomfort.
Health Benefits of a High-Fiber Diet
Better Digestive Health
Fiber can help prevent constipation by adding bulk to stools. The added bulk stimulates movement in the intestines, so it may promote regular bowel movements.
Fiber can also act as a prebiotic, feeding beneficial gut bacteria. When the bacteria digest certain fibers, they produce what’s known as “postbiotics.” These short-chain fatty acids (SCFAs) feed cells lining the large intestine. As a result, gut inflammation can go down, and motility may improve.
Improving motility in the gut may lower the risk of colon cancer.
Potentially Avoid Colon Cancer
Improving motility in the gut may also help you avoid colon cancer. A large prospective study of over 75,000 participants looked at fiber and cancer risk. Higher fiber intake from foods was associated with a lower risk of colorectal cancer.
Improve Heart Health
Increasing your fiber intake may protect against heart disease. Research shows as insoluble fiber increases, blood pressure and triglyceride levels decrease. A lower fiber intake is also associated with higher insulin levels. It’s no wonder high-fiber cereals are advertised as “heart-healthy.” Whether they truly are is the subject of another blog post.
Blood Sugar Balance
Soluble fiber can slow down sugar absorption, helping to stabilize blood glucose levels. This slower digestion prevents rapid spikes in blood sugar after meals. It does so by carefully regulating glucose release into the bloodstream. This is important for avoiding metabolic syndrome and diabetes.
High-fiber diets are also associated with improved insulin sensitivity. Insulin is a hormone responsible for regulating blood sugar levels. Increased insulin sensitivity means cells can more effectively use glucose from the bloodstream. That also helps to maintain stable blood sugar levels, reducing diabetes risk.
A Healthy Weight
High-fiber foods are often filling, which can help control appetite. It may do so by increasing a gut hormone called cholecystokinin (CCK). Researchers have found that fiber promotes the release of CCK into the bloodstream, reducing appetite. So, including plenty of fiber may help with weight loss if needed.
A 2023 study looked at the success of a fiber-rich diet in 4,477 people over three years. Over 62% of them lost weight. On a high-fiber diet, the average weight loss was 7.23 pounds (3.28 kilograms).
Which Foods Are Highest in Fiber?
Several foods are high in fiber, so there are lots of options. Incorporating these foods into your diet can certainly support digestive health. However, it may also improve overall health by supporting a healthy immune system.
Beans and Legumes
Beans, lentils, chickpeas, and green peas are excellent sources of fiber. For instance, black beans, kidney beans, navy beans, and pinto beans are particularly high in fiber. According to the USDA’s FoodData Central, here’s the fiber content of three common legumes:
- Split peas have 16.3 grams per cup
- Black beans have 15 grams per cup
- Chickpeas have 12.5 grams per cup
There are many types of beans, and all are high in fiber. Lentils are available in green, black, and even red. Between beans, lentils, and peas, there are many options to work with.
Keep in mind that beans are also high in lectins which can damage the digestive system. When I was actively healing from autoimmune disease I avoided beans entirely. This article gives more details and explains some easy ways to reduce lectins and still get the benefits of beans.
Whole Grains and Grain-Like Seeds
Whole grains, if you eat them, are also excellent sources of fiber. Oats, brown rice, spelt, einkorn, and barley are high in fiber. Opting for whole grain varieties instead of refined grains increases your fiber intake. While brown rice is higher in fiber than white, our family only eats white rice (here’s why!).
Grain-like seeds, like quinoa and millet, are also good sources of fiber.
Just increasing your veggies can improve your fiber intake. Artichokes, broccoli, Brussels sprouts, carrots, kale, and other leafy greens are high-fiber vegetables. Peas (also a legume) and sweet potatoes both contribute decent amounts of fiber.
Berries and Other Fruits
Raspberries, blackberries, strawberries, and blueberries are some of the best fruit sources. These fruits are also rich in antioxidants, which have additional health benefits. Pears, apples (with the skin), oranges, and bananas are also great sources of fiber.
Nuts and Seeds
Almonds, chia seeds, flax seeds, and sunflower seeds are also fiber-rich. You can easily add them to cereals, yogurt, or on top of salads. Chia and flax seeds are also high in plant-based omega-3 fatty acids.
How to Get Enough Fiber if You Don’t Eat Grains?
You don’t need to eat whole wheat berries daily to get your fiber in. If you’re following a grain-free or Paleo diet, there are still plenty of ways to get fiber outside whole grains.
- Non-Starchy Vegetables: Broccoli, kale, Brussels sprouts, bell peppers, asparagus, and cauliflower are fiber-rich. They also align with Paleo diet principles, and supply needed vitamin C.
- Root Vegetables: While some people may limit root vegetables due to carbs, sweet potatoes and carrots are good sources of fiber.
- Fruits: Berries tend to be lower in sugar and higher in fiber compared to prunes and other fruits. Avocados are also a good source of fiber, potassium, and healthy fats.
- Nuts and Seeds: Almonds, walnuts, flaxseeds, chia seeds, and pumpkin seeds are “Paleo.” They’re also good sources of fiber and healthy fats.
- Coconut: Coconut products, including coconut meat and coconut flour, are good sources of dietary fiber in Paleo recipes.
Who Should Avoid High-Fiber Foods?
While fiber is generally beneficial, certain people may need to limit high-fiber foods — at least for a while. Here’s who should consider limiting their intake of high-fiber foods:
Those with Active Disease Flares
Fiber can aggravate some digestive conditions like Crohn’s disease, ulcerative colitis, and diverticulitis. It may be fine during remission but not during flares. In such cases, high-fiber foods may need to be temporarily limited as directed by a healthcare provider.
Those with Chronic IBS or SIBO
Those with irritable bowel syndrome (IBS) or small intestine bacterial overgrowth (SIBO) may not do well with more fiber. They may experience bloating, cramping, or digestive distress from adding high-fiber foods. Adjusting the types or amounts of fiber may help. For example, following a low-FODMAP diet may reduce symptoms.
FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. It refers to certain carbohydrates that may worsen symptoms in those with these gut disorders. Read more about a Low FODMAP Diet.
Those Recovering From Surgery
Doctors may recommend a low-fiber diet following certain types of surgeries or medical procedures. Gastrointestinal surgeries are a good example. When fully recovered, it may be fine to add back higher fiber foods. Check with your doctor to know for sure.
How to Include More Fiber in Your Diet
To increase your fiber intake, focus on eating whole foods. You can also choose to use recipes with high-fiber ingredients. Here are some easy ways to get more fiber in your diet:
Soups and Stews
Add beans, lentils, chickpeas, and peas to soups and stews. Or, just focus on recipes that already include legumes. Here are a few ideas!
Legumes are a reliable way to increase your fiber intake. You can always add a can or two to a vegetable-based soup to increase the fiber count.
Eat Raw Vegetables with Dip
For an easy lunch or healthy snacking, bring out a variety of raw vegetables. Then, pair them with fiber-rich hummus or guacamole. Try your crudites with these:
When pairing raw vegetables with fiber-rich dip, you’re doubling your efforts!
Enjoy Nuts & Seeds as Snacks
Snack on soaked or sprouted nuts and seeds. Almonds, walnuts, pecans, sunflower seeds, and pumpkin seeds are high in fiber and delicious. Toasted and included in a trail mix, they make a satisfying snack. Chia seeds are easy to include as a “pudding.” Try these!
Nuts and seeds also show up as “flours” in grain-free pancakes and baking.
Embrace Grain-Free Flour Substitutes
Grain-free baking automatically uses high-fiber ingredients like nut flours, seed flours, and coconut flour. Here are some ideas to get you started:
When you get away from white flour and refined pasta, increasing fiber is almost a given. Enjoy your fruits and vegetables in their whole, unprocessed form, and you’ll be surprised how easy (and delicious) it is to get your high-fiber foods in.
Do you try to eat a high-fiber diet? How do you purposely include more fiber each day? Share with us below!