Fiber

Fiber is an essential nutrient that the human body cannot function properly without. It provides a feeling of fullness, which is helpful in the weight loss process, and also supports the overall functioning of the digestive system.

What Is Fiber?

Dietary fiber, also known as roughage, is a plant-based substance that is not digested or absorbed in the digestive tract.

It is a mixture of polysaccharide and non-polysaccharide substances. These elements are often referred to as residual substances, which is why a diet high in fiber is sometimes called a fiber-rich diet.

The composition of fiber includes compounds such as:

cellulose,
pectin,
hemicelluloses,
lignins,
vegetable gums,
resistant starch.

Types of Fiber

In plant-based products, we can distinguish between water-soluble and insoluble fiber.

Soluble fiber

Water-soluble fiber is primarily found in the flesh of plant products and includes compounds such as pectins and vegetable gums.

Soluble dietary fiber helps promote a feeling of satiety and can lower cholesterol levels, particularly reducing LDL. It also helps reduce fasting blood glucose levels and stabilizes blood sugar after meals.

Insoluble fibre

Insoluble fiber is primarily found in the skin and seeds of plants. This group includes compounds such as lignin, resistant starch, cellulose, and hemicellulose.

Insoluble fiber promotes intestinal peristalsis, increases the frequency of bowel movements, and helps prevent constipation. Additionally, it provides a longer-lasting feeling of satiety.

Sources of Dietary Fiber

Sources of fiber include many commonly available foods, particularly fruits, vegetables, and wholegrain cereal products. Excellent sources of fiber include:

oatmeal,
oat bran,
nuts,
wholegrain cereal products, e.g. wholemeal bread,
cereal bran,
dried fruits,
leguminous seeds (legumes),
linseed,
raw fruit, e.g. apples, strawberries, pears, oranges,
vegetables, incl. carrots, celery, green beans, dark leafy vegetables, cucumbers.

Fiber Intake Requirements

According to the World Health Organization, it is recommended to consume at least 25 grams of fiber per day. The general guidelines suggest that the body should receive between 20 grams and 40 grams of dietary fiber daily, with the exact amount depending on factors such as gender.

The need for fiber can also be estimated using a simple formula. Simply divide your current body weight by two, and the result will be your individual daily requirement for dietary fiber (measured in grams).

For individuals suffering from constipation and diabetes, the daily fiber requirement is slightly higher. Research suggests that in these cases, the daily intake of fiber should be increased to approximately 60 grams.

In cases where meeting the fiber requirement through diet alone is challenging, dietary supplements rich in fiber can be used as an additional aid.

Benefits of Dietary Fiber

Dietary fiber plays several important roles in the body, and its effects vary depending on the type of fiber.

Insoluble fiber irritates the intestinal walls, which enhances digestive processes, accelerates intestinal peristalsis, and stimulates blood flow. It also increases stool volume and contributes to the feeling of satiety. Additionally, it supports the proper secretion of digestive juices in the stomach. On the other hand, soluble fiber helps protect against diarrhea and thickens the digestive content. It slows glucose absorption, lowers cholesterol, and reduces the absorption of triglycerides, positively influencing blood lipid profiles. This type of fiber can also help cleanse the body of toxic waste products and heavy metals.

The fiber supplied to the body moves through the entire digestive tract and supports the functioning of the whole organism by:

Regulating bowel function
Improving the digestive process
Providing a longer-lasting feeling of satiety
Helping with constipation and flatulence
Supporting metabolism and facilitating defecation
Potentially aiding in maintaining a healthy body weight
Lowering cholesterol and regulating blood sugar levels
Potentially having a beneficial effect on blood pressure

Dietary Fiber and Weight Loss

Fiber regulates intestinal peristalsis and, by absorbing water, swells to fill the stomach and intestines. This helps create a feeling of satiety, reduces hunger, and limits the number of meals consumed. Additionally, dietary fiber plays a role in regulating the absorption of fats and carbohydrates in the body.

Products rich in fiber are also low in energy and contain little fat, meaning they do not add unnecessary calories to the body.

A high-fiber diet helps control appetite, reduces food intake, and encourages healthier eating choices. As a result, we consume fewer fats and sugars, which can lead to the loss of excess weight.

Fiber Deficiency

Insufficient fiber intake primarily contributes to constipation.

A low intake of fiber can indirectly promote the development of lifestyle diseases, such as atherosclerosis. Additionally, a low-fiber diet is often high in calories, which can increase the risk of overweight and obesity.

Excessive Fiber Intake

Excessive fiber intake, around 80 grams per day, or a sudden increase in dietary fiber, can lead to side effects such as bloating or abdominal pain.

A large portion of fiber may also reduce the effectiveness of certain medications, such as cholesterol-lowering drugs. It is recommended to take these medications two hours before or after a meal to avoid interference.

Soluble dietary fiber components may also interfere with the absorption of certain minerals, such as iron, zinc, or calcium. Therefore, it is important not to consume excessive amounts of fiber throughout the day.

Natural Fiber vs. Fiber Supplements

The most beneficial and safest way to provide fiber to the body is through the daily diet. With a varied diet rich in fruits and vegetables, there should be no issue with properly balancing and meeting the body's fiber requirements.

Sometimes, it can also be beneficial to turn to fiber-rich dietary supplements. These supplements are recommended for people suffering from constipation, those looking to lose weight, or individuals who are unable to meet their fiber needs through their diet alone.

It is also important to remember that when taking fiber-rich supplements or following a high-fiber diet, you should regularly drink fluids to prevent unpleasant digestive issues.