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Why fiber is so important for the body

Vegetables, fruit and pulses
Dietary fiber is important for the body. You can find out why this is the case below. Photo: Getty Images

October 26, 2024, 2:18 pm | Read time: 4 minutes

Dietary fiber contains no nutrients – and yet it is indispensable for the body. Alongside vitamins and various minerals, fiber is important for our health. FITBOOK editor Isa Kabakci explains why this is the case.

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The small intestine cannot digest fiber. However, this does not mean that it does nothing for the body – on the contrary. Far from being unnecessary ballast, it has positive effects on the body and is good for your health. It stimulates digestion and is a welcome food for the beneficial bacteria in the large intestine. That’s why you should include enough of it in your diet.

What exactly is dietary fiber?

Before we go into the various aspects of dietary fiber, let’s first clarify what it is. “Fiber” may sound negative, but fiber has many positive effects on our bodies. According to the German Nutrition Society (DGE), it is an indigestible food component that is mainly found in plant-based foods such as fruit, vegetables, whole grain products, pulses, nuts, and seeds.1 Chitin is an exception to this rule. Most dietary fibers are complex carbohydrates.

Dietary fiber has these functions

Dietary fiber is important and healthy for the body as it promotes digestion and prevents constipation. It also helps to regulate blood sugar levels by slowing down the digestion and absorption of carbohydrates.

It can also help to lower blood cholesterol levels as it binds bile acids in the intestine, which are produced from cholesterol, and supports their elimination from the body. Dietary fibers are also beneficial in terms of satiety. They swell up in the stomach and prevent hunger pangs.

Fiber is also essential for intestinal health, as it acts as a prebiotic to promote the growth of healthy intestinal bacteria. These bacteria ferment them into short-chain fatty acids, which have an anti-inflammatory effect and support the health of the gut and the entire immune system.2

A study by Friedrich Schiller University Jena is also interesting. It shows that dietary fiber promotes the occurrence of certain types of bacteria that reduce fat absorption and protect against obesity. However, further studies are needed to confirm the long-term effects. The results were published in the journal Nature Metabolism.3

Water-soluble and water-insoluble dietary fibers

A distinction must also be made between water-soluble and water-insoluble dietary fibers. The most important characteristics of each are listed below:

Water-soluble

This fiber is usually found in fruits and vegetables. These include pectins, beta-glucans, oligofructose, and inulin. They dissolve in water and form a gel-like substance in the intestine that nourishes the intestinal flora. Water-soluble fiber also helps control blood sugar and can help lower cholesterol levels. In addition, they slow down digestion and can help with diarrhea by binding water in the intestines.

Water-Insoluble

Water-insoluble fiber is usually found in cereal products, nuts, potatoes, and similar foods. As the name suggests, this fiber does not dissolve in water and passes through the digestive tract undigested. As a result, they increase the volume of stool, speed up the intestinal transit time, and promote regular bowel movements. Water-insoluble dietary fibers support the feeling of satiety, prevent intestinal problems, and promote digestion. These include cellulose, lignin, and others.

How much fiber is necessary?

As beneficial as fiber is for the body, you should still be careful with your intake. The German Nutrition Society (DGE) recommends a fiber intake of around 30 grams per day for adults. The European Food Safety Authority (EFSA) differentiates the recommendations according to age group and gender: for men, the minimum daily value is 30 grams, and for women, 25 grams. For adolescents, the recommended value varies between 20 and 30 grams.4

More on the topic

Nutritional tips for incorporating more fiber

The question now arises as to how best to incorporate fiber into the diet. This is where vegetables really shine. Artichokes and salsify are particularly rich in fiber, while peppers, carrots, and broccoli are also good sources, according to the DGE, as are pulses such as broad beans and chickpeas.

And products made from wholegrain cereals also score highly in terms of fiber: wholegrain pasta, for example, contains more than twice as much fiber as the version made from light flour. Incidentally, mushrooms such as chanterelles or porcini mushrooms are also good sources of fiber – as are the pears and berries mentioned above.

If you want to include more fiber in your diet, it’s best to do this step by step instead of changing every meal of the day. Otherwise, there is a risk of flatulence, diarrhea, or cramps – the intestines may first have to get used to the increased intake of fiber.

Content includes material from dpa

This article is a machine translation of the original German version of FITBOOK and has been reviewed for accuracy and quality by a native speaker. For feedback, please contact us at info@petbook.de.

Topics Darmgesundheit Gemüse Obst

Sources

  1. Deutsche Gesellschaft für Ernährung e. V. Dietary fiber. Selected questions and answers on dietary fiber</a>. (aufgerufen am 28.08.2024)</em> ↩︎
  2. AOK. What actually is dietary fiber?</a> (accessed 28.08.2024)</em> ↩︎
  3. Li H, Zhang L, Li J, Wu Q, Qian L, He J, Ni Y, Kovatcheva-Datchary P, Yuan R, Liu S, Shen L, Zhang M, Sheng B, Li P, Kang K, Wu L, Fang Q, Long X, Liu X, Wang X, Li Y, Ye Y, Ye J, Bao Y, Zhao Y, Xu G, Panagiotou G, Xu A, and Jia W (2024): Resistant starch intake facilitates weight loss in humans by reshaping the gut microbiota. </a>Nature Metabolism. </em> ↩︎
  4. European Food Safety Authority. Scientific Opinion on Dietary Reference Values for carbohydrates and dietary fiber</a> (accessed 28.08.2024) </em> ↩︎