Fiber-rich Diet / Fiber-containing Foods
Fiber is an indigestible component of food that is produced by plants. Although it cannot be digested, it serves as food for the body's own intestinal bacteria. The two most well-known forms are water-soluble and insoluble fiber. Most plant-based foods contain a mix of both types. People who consume a fiber-rich diet have a lower susceptibility to chronic diseases 1. Fiber-rich foods contain many different types of fiber such as cellulose, hemicellulose, lignin, inulin, and pectin, which are needed for a healthy gut flora and have cancer-preventive effects (see also Fiber and Cancer) 2. Therefore, in populations with a low average fiber intake, doubling the total fiber intake can reduce the risk of colon cancer by 40 % 3.
If too much fiber-rich food is consumed, the digestion speed is accelerated, which results in fewer nutrients being absorbed and being eliminated faster. At the same time, it can lead to bloating and abdominal pain 4.
The more unprocessed and natural the plant-based foods are, the more fiber they ultimately contain. It is also recommended to drink plenty of water when consuming fiber, so that the fiber can have its full effect.
You can find a list of high-fiber foods here.
Below are some fiber-rich foods that should be consumed regularly as part of a healthy diet.
Fiber in Grains
Whole grain products are the best sources of fiber-rich foods. Therefore, oatmeal and spelt flakes should be consumed regularly. The pseudo-grains Chia seeds (34.4 g per 100 g), buckwheat (10 g), Quinoa (7 g), amaranth (6.7 g), and Canihua (6.1 g) are also excellent choices for a fiber-rich diet. Brown (3.4 g) and wild rice (6.2 g) are also recommended.
Seeds and nuts as fiber bombs
The daily requirement can quickly be met with psyllium seeds (48.5 g), almonds (12.5 g), walnuts (6.7 g), macadamia nuts (8.6 g), hazelnuts (9.7 g), pistachios (10.3 g), pine nuts (3.7 g), pecans (9.6 g) and flaxseed (27.3 g). However, the high calorie count of these foods should be noted.
Fiber in Legumes
All legumes are consistently high in fiber. They contain more fiber than fruits and vegetables. Therefore, peas (5 g), lentils (10.7 g), soybeans (9.3 g), mung beans (16.3 g), kidney beans (24.9 g), white beans (15.2 g), and peanuts (8.5 g) should not be overlooked.
In fruits, fiber is mainly found in the skin. In most cases, the skin is rich in insoluble fiber while the inside contains more soluble fiber. Apples and pears with skin are very good sources of fiber-rich fruit. Raspberries (6.5 g) and blackberries (5.3 g) are also suitable for enriching the diet with fiber. Due to the many small seeds in the fruit, the fiber content is higher than in other fruits. In addition, exotic fruits such as peaches (1.5 g), figs (2.9 g), bananas (2.6 g), mangoes (1.6 g), persimmons (3.6 g), avocado (6.7 g), grapefruit (1.1 g), and oranges (2.4 g) are rich in fiber.
Find more fiber-rich fruit in this list.
There is a rule of thumb for vegetables too. The darker the color of the vegetable, the higher its fiber content. Additionally, non-starchy vegetables are especially rich in fiber 5. Thus, broccoli (2.6 g), spinach (2.2 g), zucchini (1 g), Brussels sprouts (3.8 g), carrots (2.8 g), beets (2.8 g), and artichokes (5.4 g) are very rich in fiber.
However, potatoes (2.2 g) also contain fiber. The same applies to potatoes as to fruit. The skin is particularly rich in fiber. Additionally, excessive loss of vitamins and minerals during cooking is reduced when the skin is left on.
As mentioned earlier, processed foods no longer contain the maximum amount of fiber. Nevertheless, it is relatively easy to meet the daily requirement of 25 to 38 g of fiber with their consumption. Significant sources include bulgur (12.5 g), pumpernickel bread (6.5 g), whole-grain bread (6 g), and unsweetened popcorn (14.5 g).
Bran (42.8 g), which is produced during the processing of grains, is made up of almost half its weight in fiber. It can be added to breakfast cereal in small quantities.
Avoidance of refined flour products, such as white bread or toast, which contain only very small amounts, is particularly recommended.
Foods with water-soluble fiber
Fruits: banana, plums, apple, pear, blackberries, blueberries, strawberries, apricot, citrus fruits
Vegetables: broccoli, potatoes, carrots, root vegetables
Legumes such as lentils and beans
Grains: oats, spelt, barley
Psyllium husk (has a laxative effect)
Foods with water-insoluble fiber
Fruit: Apple, Pear, Blueberries, Oranges, Grapes, Kiwi, Avocado
Vegetables: Broccoli, Zucchini, Green Beans, Cucumber, Onion, Carrots, Cauliflower, Potatoes with skin
Grains: Whole grains, Wheat bran
Nuts and Seeds
Prebiotic fibers are found in larger quantities in asparagus, onions, garlic, leeks, bananas, artichokes, agave, chicory, and yams, and in smaller amounts in wheat, rye, and barley 6. They serve as a food source for gut bacteria and promote a healthy gut flora.