Surely you have heard the phrase that fiber is a “broom” that helps “revenge” the intestines. Despite the fact that this, to some extent, is true – the perception of fiber solely as a coarse ballast substance for cleaning the digestive system distorts reality.
Strictly speaking, fiber is just a type of carbohydrate. And the carbohydrates themselves are divided according to the number of structural elements – from single (sucrose and fructose) to ordered linkages of hundreds of thousands of molecules (fiber and various types of starch).
Fiber – What is it?
Fiber is a broad class of complex high molecular weight carbohydrates that form the structure of plants. Soluble and insoluble fiber are isolated – the first is able to be processed by intestinal bacteria, and the second (cellulose and lignin) leaves the body almost unchanged.
In terms of health and nutrition, coarse insoluble fiber is more effective than soluble fiber. In particular, it helps maintain stable blood sugar levels¹, essential for long-term satiety.
In turn, soluble fiber is able to absorb water, turning into a gel-like substance in the gastrointestinal tract. The advantage of this fiber is that it serves as food for beneficial bacteria – acting as a natural prebiotic.
Where is it found?
Fiber is found in all-natural foods (with the exception of butter, meat, milk, and eggs). Normally, the pulp of a plant is made up of cellulose, the cell wall is impregnated with lignin, and gum appears at the site of damage to the plant – preventing microorganisms from getting inside.
Various types of gum (soluble fiber) are widely used in the food industry to thicken the structure – for example, agar and carrageenan.
In turn, mucus (mucopolysaccharides), also formally classified as soluble fiber, is found in plants that need to retain moisture (aloe and cacti).
Which foods are the highest in fiber?
Since fiber is actually the structure of the plant, it is abundant in the bran (separated from the grain of the shell); seeds; dried mushrooms, vegetables, and fruits (due to the removal of water, the percentage of fiber in the mass increases). Recall also that buckwheat or quinoa grains are also seeds.
Lack of fiber in the diet negatively affects metabolism and also contributes to weight gain. In practice, this is often associated with an excess in the diet of fast carbohydrates (sugar, sweets, pastries, white rice) and refined foods against the background of a lack of vegetables.
It must be understood that bread and pasta made from white flour contain very little fiber – and cannot be considered as its only source.
Brief table of fiber content in various products (per 100g)
- Bran: 40 – 45g
- Seeds (including flaxseed and chia seeds): 25 – 30g
- Dried mushrooms: 20 – 25g
- Dried fruits: 12 – 15g
- Whole grain cereals (oatmeal, buckwheat, quinoa): 10 – 15g
- Vegetables: 7 – 10g
- Legumes (lentils, beans, chickpeas): 9 – 13g
- Whole grain bread: 8 – 9g
- Berries (blueberries, cranberries): 5- 8g
- Sweet fruits (peaches, oranges, strawberries): 2- 4g
- Carrots: 2 – 3g
The benefits of bran
Bran is the shell of grains of various types. There are wheat, rye, and oat bran – each of these types contains its own combination of fiber. For example, oat bran (like oatmeal itself) is rich in a unique type of soluble fiber called beta-glucan.
Oat fiber is a classic prebiotic – it is fermented by the microflora of the large intestine, stimulating its further growth and vitality (strengthening beneficial bacteria and inhibiting harmful ones). In particular, such fiber helps the bacterial synthesis of a number of vitamins.
Fiber: The norm and recommendations
Modern nutritionists say that the norm of fiber in proper nutrition is about 30 g per day – this amount helps to maintain normal not only blood glucose levels but also cholesterol levels, as well as blood pressure.
The exact rate is calculated based on the daily calorie intake (recall, it depends on body weight and the level of activity of a person) – amounting to 14 g of fiber per 1000 kcal. The maximum amount of fiber per day should not exceed 50 g.
Excess fiber in the diet can provoke digestive difficulties (first of all, bloating – as well as constipation). That is why it is necessary to increase the intake of fiber with food gradually – and without excessive fanaticism.
How to consume more fiber?
Here are some practical tips to help ensure you get enough fiber in your daily diet:
- Try to eat 3-5 servings of non-starchy vegetables each day (one serving is ½ cup cooked or 1 cup cooked vegetables).
- Eat 2 servings of high-fiber fruits daily (one serving is a handful of berries, a small apple, or a pear).
- Instead of products made from premium wheat flour, give preference to whole grain cereals (oatmeal, pearl barley, buckwheat, quinoa, bulgur, etc.).
- As a snack, use nuts without added salt (one serving is ¼ cup or about a handful).
- Sprinkle vegetable salads (or natural yogurt) with a tablespoon of ground chia seeds or flaxseeds.
- Include legumes (lentils, peas, chickpeas) in your diet – they contain a lot of fiber.