Fiber, or dietary fiber, is a unique plant compound that differs from other carbohydrates in that our body’s enzymes cannot digest it. However, this inability to digest it has surprisingly positive effects on our health. Fiber plays an important role in maintaining a healthy digestive system, regulating cholesterol and blood sugar levels, and reducing the risk of various chronic diseases.
Research shows that getting enough fiber in your diet can also help maintain a healthy weight and boost your immune system, working in conjunction with other plant compounds that support immunity.
In this article, we’ll take a closer look at what fiber is, what its health benefits are, where it comes from, and how to get more fiber into your diet. We’ll also discuss the recommended daily allowance and potential pitfalls when consuming fiber.
What is fiber?
Dietary fiber is a carbohydrate polymer of plant origin that is not digested by the digestive enzymes of the human intestine. According to the definition of the European Food Safety Authority (EFSA), fiber is an indigestible carbohydrate that is not broken down in the small intestine but can be partially or completely fermented in the large intestine.
Fiber is divided into two main groups: soluble and insoluble. Each group has different effects on the body and affects the digestive system differently.
Soluble vs. Insoluble Fiber: Key Differences
Soluble fiber forms a gel-like mass in water that:
- slows down the digestive process
- helps regulate blood sugar levels
- lowers cholesterol levels
- feeds beneficial gut bacteria
The main sources of soluble fiber are oats, citrus fruits, apples, barley, and legumes.
Insoluble fiber does not break down or change in water, but it:
- increases stool volume
- speeds up the movement of food through the digestive tract
- helps prevent constipation
- maintains a healthy gut pH
Insoluble fiber is abundant in wheat bran, vegetables, whole grain cereals, and nuts.
Gut health directly depends on the right amount of fiber in the diet.
They act as a prebiotic – food for beneficial intestinal bacteria, which produce short-chain fatty acids during fermentation, which have anti-inflammatory effects.
Health benefits of fiber
Digestive system support
- Fiber helps maintain normal bowel function
Cholesterol reduction (certain fibers only)
- Beta-glucans in oats help maintain normal blood cholesterol levels
- Beta-glucans lower cholesterol, which helps reduce the risk of heart disease (with the appropriate dose and conditions)
Glucose (sugar) control
- Soluble fiber from oats/barley helps reduce the rise in blood glucose after meals
Weight control (psyllium, glucomannan, etc.)
- Glucomannan, when used with a low-calorie diet, helps with weight loss
Regular bowel movements (psyllium)
- Psyllium helps maintain regular bowel movements
Main sources of fiber in the diet
Sources of fiber are diverse and can be easily included in the daily diet. The diet of the Lithuanian population is characterized by some traditional fiber-rich ingredients, but there are also many other products that are worth including.
Grain products
- whole grain rye bread – a traditional part of Lithuanian cuisine, rich in insoluble fiber
- whole grain wheat, spelt, rye or barley flour products
- whole grains: buckwheat, millet groats, brown rice
- oats and oatmeal – an excellent source of soluble fiber
- wheat, oat and rye bran – have an extremely high fiber content
One bowl of cooked oats contains about 4 grams of fiber, while 100 grams of whole grain rye bread provides about 6 grams of fiber.
Vegetables and legumes
- beets, carrots, cabbage – traditional Lithuanian vegetables, rich in fiber
- brussels sprouts, broccoli, cauliflower
- potatoes with skins
- root vegetables: parsnips, radishes, Jerusalem artichokes
- legumes: peas, beans, lentils, chickpeas, soybeans – some of the richest sources of fiber
A cup of cooked beans provides as much as 10-15 grams of fiber, which is almost half of the recommended daily intake.
Fruits and berries
- apples – especially with skin (about 4-5 g of fiber in one medium apple)
- pears
- plums and prunes
- raspberries, black and red currants, blueberries – rich sources of soluble and insoluble fiber
- strawberries and other berries
Seasonally growing berries in Lithuania are not only an excellent source of fiber, but also rich in antioxidants and vitamins.
Nuts and Seeds
- flaxseeds – about 3g of fiber per tablespoon
- chia seeds
- pumpkin seeds
- sunflower seeds
- hazelnuts, almonds, walnuts
Nuts and seeds are also rich in healthy fats, protein and minerals, making them a valuable source of nutritious fiber.
How to increase the amount of fiber in your daily diet?
Integrating fiber into your daily diet can be simple and delicious:
- for breakfast, choose oatmeal with berries and seeds
- eat vegetables and fruits with their skins, if possible
- replace white bread with wholemeal bread
- add chickpeas or beans to salads
- choose fruits, vegetables or a small handful of nuts for snacks
- experiment with new products, such as innovative plant-based drinks or teas that are rich in fibre
- replace white rice with brown rice and regular pasta with wholemeal
The recommended daily intake of fibre for adults is 25-38 grams per day. Women are generally advised to consume at least 25 g and men – 38 g of fibre per day. Unfortunately, studies show that the average Lithuanian resident consumes only about 15-20 grams of fibre per day, which is significantly less than recommended.
Guidelines, recommendations and possible mistakes in fiber consumption
While the health benefits of fiber are undeniable, it is important to know how to properly include it in your diet and avoid potential problems.
How to increase fiber intake correctly?
Increase fiber intake gradually. A sudden increase in fiber intake can cause unpleasant digestive disorders:
- increased gas accumulation in the intestines
- bloating
- abdominal pain
- diarrhea or constipation
It is recommended to increase fiber intake by 3-5 g per week until you reach the recommended amount. This way, the intestines will have time to adapt.
Fiber consumption rules
- Drink enough water – fiber absorbs water, so it is necessary to drink at least 1.5-2 liters of fluids per day
- Pay attention to food labels – “whole grain” or “with fiber” labels do not always mean that a product is high in fiber; evaluate the fiber content per 100 g of the product
- Combine different types of fiber – both soluble and insoluble fiber are important for health
- Be careful if you have certain medical conditions – in cases of irritable bowel syndrome, Crohn’s disease or ulcerative colitis, you may need to limit certain fibers
Signs of Fiber Deficiency
Insufficient fiber intake can manifest itself in the following symptoms:
- Persistent constipation
- Weight gain
- Lack of energy
- High blood cholesterol
- Unstable blood sugar
Fiber supplements: When are they needed?
While it is best to get fiber from natural food sources, fiber supplements can sometimes be used. They are particularly helpful for:
- older people who have difficulty eating enough food
- those with specific digestive disorders
- those after certain surgeries
- those on specific diets
However, before taking any fiber supplements, it is important to consult a doctor or dietitian. Supplements cannot replace the benefits of a balanced, varied diet, as we also get other important nutrients along with natural fiber.
It should be noted that excess fiber can also have negative consequences: reducing the absorption of minerals, especially calcium, iron and zinc. Therefore, it is important not to exceed the recommended amount without the supervision of a health professional.
Special Recommendations
- Children’s fiber needs vary by age. Approximate formula: child’s age + 5 = recommended fiber intake in grams per day
- For pregnant women, fiber is especially important in combating constipation, which often occurs during pregnancy
- For athletes, adequate fiber intake helps maintain energy levels and good digestion
- For diabetics, fiber helps stabilize blood sugar levels
If you are planning to significantly change your diet and the amount of fiber in it, it is always recommended to consult a health professional – a doctor, dietitian or nutritionist. They will help you create an individual plan that meets your health condition and needs.
Conclusions
Fiber is an integral part of a healthy diet, with many positive properties for the body. It helps maintain a healthy digestive system, regulate blood sugar and cholesterol levels, control weight and reduce the risk of developing various chronic diseases.
Although the current fiber intake among Lithuanians often does not reach the recommended norm, small but consistent dietary changes can significantly improve the situation. By consuming more fruits, vegetables, whole grains, legumes, nuts and seeds, you can easily increase the amount of fiber in your daily diet.
It is important to remember that the amount of fiber should be increased gradually and to drink enough water. The need for fiber may vary from person to person, so it is worth paying attention to the signals sent by your body and, if necessary, consult a health professional.
A balanced, fiber-rich diet is an investment in long-term health and well-being. Start with small but consistent changes, and your body will respond with better well-being, energy, and resistance to disease.
Frequently Asked Questions
What is dietary fiber?
Dietary fiber is a carbohydrate found in plants that cannot be digested by the body’s enzymes, but it is beneficial for digestive health and overall health.
How much fiber should you consume per day?
Adults are recommended to consume 25-38 g of fiber per day – at least 25 g for women and 38 g for men, but individual needs may vary depending on age, gender and health status.
What are the best natural sources of fiber?
The best natural sources of fiber are whole grains, legumes, vegetables, fruits, berries, nuts and seeds.
Can you consume too much fiber?
Yes, too much fiber can cause digestive problems and interfere with mineral absorption; fiber intake should be increased gradually and with plenty of water.
Are fiber supplements as effective as fiber from food?
Fiber supplements can help you reach your recommended fiber intake, but they should not replace a well-balanced, varied diet unless advised by a healthcare professional.