Dietary fiber is categorized under non-nutrient food but it is an essential part of a human diet.
The body needs dietary fiber for many reasons because it can help to manage body weight, prevent constipation. It is crucial for keeping the gut healthy & reduces chronic health conditions like heart disease and type 2 diabetes.
Dietary fiber is the indigestible part of plant foods. It comprises the edible parts of plants that cannot be digested or absorbed in the small intestine and passes into the large intestine intact.
Sources of Dietary Fiber:
Dietary fiber is found from plant sources:-
Fruits- Oranges, pears, strawberries, blackberries, raspberries, currants.
Vegetable- Brussel sprouts, onion, garlic, broccoli, corn, peas, green beans,
Pulses- lentils, chickpeas, beans
wholegrains- Oat bran cereals & all bran, whole and mixed grain
Types of Dietary Fiber:
There are two types of dietary fiber according to solubility in water:
• Insoluble fiber– it does not dissolve in water and adds bulk to the stool, it prevents constipation. Cellulose, Hemicellulose, Lignin
Insoluble fibre is found in wholegrain food products, cereals, seeds, nuts, wheat bran and the skin of fruit and vegetables
• Soluble fiber- it absorbs water, forming a gel-like substance in the digestive system. Soluble fiber may help lower cholesterol levels and help to regulate blood sugar levels. eg- Pectin, Gums, Mucilages.
Soluble fiber is found in apple, oats, peas, beans, barley, citrus fruits, carrots and psyllium.
| Type of Fiber | Element of the fiber | Explanation | Sources |
| Insoluble fiber | cellulose | The primary structural component of plant cell walls is cellulose. It is also known as a complex carbohydrate. It is composed of the long chains of glucose molecules which are linked together. Human beings are capable of breaking down cellulose as they lack the necessary enzymes required for the same. Thus, they pass through the digestive system as it is. As a result they provide bulk to the stool and helps in digestion | whole grains such as whole wheat, oats, vegetables such as broccoli, carrot fruits such as apples, grapes, berries etc and legumes such as beans, lentils, peas. |
| Hemi-cellulose | These are a diverse group of polysaccharides which are found in the plant cell walls. Hemicellulose are the branched polymers which are made up of various sugar molecules. Hemicellulose, unlike cellulose, can partially soluble in the water, adding to the dietary fiber content. When consumed by humans, it contributes to the plant’s structural integrity and provides some dietary fiber benefits. | whole grain such as wheat, rye, and barley. vegetables such as spinach, cauliflower, and green beans, fruits such as avocados and bananas, legumes such as chickpeas and soybeans | |
| lignins | The non-carbohydrate polymer found in plant cell walls, primarily in wood plants, is known as Lignin. In the human digestive system, it provides rigidity to plant structures and is resistant to digestion by enzymes. Lignin is categorized as the insoluble fiber, however, it doesn’t contribute majorly to bulk in the stool. Nevertheless, it still has a role in promoting overall digestive health. | whole grain such as wheat and corn, vegetables such as carrots, as well as kale and broccoli fruits such as Berries, especially strawberries and raspberries, nuts and seeds such as almond, walnut, flaxseeds etc. | |
| Soluble Fiber | Pectin | It is a soluble fiber which is found in the cell walls of fruits and vegetables, primarily in apples, citrus fruits, and berries. Pectin forms a gel-like substance, when mixed with water, making it of use in jams and jellies. It also nourishes the beneficial gut bacteria, acts as a prebiotic, and contributes to digestive health. | fruits such as apples, citrus fruits (oranges, lemon etc), Vegetables such as carrots, sweet potatoes. |
| Gums | This soluble fiber is derived from plants. They are frequently used as a thickening agent in food products. Gums are used in various foods and beverages to enhance texture, stability, and consistency of the product. | guar and xanthan | |
| Mucilages | These are plant-based substances with a gooey, viscous texture. When mixed with water, mucilages form a gel-like consistency. They have demulcent properties, soothing and protecting irritated tissues in the digestive tract. Mucilages contribute to digestive health by promoting smooth bowel movements and relieving constipation. | flaxseeds, psyllium husk, lady finger (okra) |
Functions of Dietary fiber
1. Adds Bulk to the Diet, Controlling Weight:
– Dietary fiber adds volume to the food without adding extra calories. This bulk fills the stomach, creating a sense of fullness or satiety, which helps in controlling appetite. Feeling full faster can prevent overeating, aiding in weight management and potentially reducing the risk of obesity-related issues.
2. Traps Carbohydrates, Slowing Glucose Absorption:
– Fiber tends to absorb the water and forms a gel-like substance during the process of digestion. This gel traps carbohydrates, slowing down their absorption in the digestive tract. This property helps in regulating blood sugar levels, preventing rapid spikes in glucose after meals, and making it beneficial for individuals with diabetes or insulin resistance.
3. Lowers Total and LDL Cholesterol:
– Soluble fiber, particularly in foods like oats, beans, and fruits, binds to cholesterol particles in the digestive system and removes them from the body. By lowering total and LDL (low-density lipoprotein) cholesterol levels, dietary fiber reduces the risk of heart disease and promotes cardiovascular health.
4. Regulates Blood Pressure and Metabolic Syndrome:
– Fiber-rich diets have been associated with reduced blood pressure. By promoting heart health and regulating blood sugar levels, fiber may lower the risk or symptoms of metabolic syndrome, a cluster of conditions that increase the risk of heart disease, stroke, and type 2 diabetes.
5. Facilitates Regularity and Alleviates Constipation:
– Dietary fiber speeds up the movement of food through the digestive system, preventing constipation by adding bulk and softness to the stool. It promotes regular bowel movements, reducing discomfort and promoting overall digestive health.
6. Balances Intestinal pH and Reduces Colorectal Cancer Risk:
– Fiber helps maintain a healthy balance in the intestinal pH levels and stimulates the production of short-chain fatty acids. This environment discourages the growth of harmful bacteria and may reduce the risk of colorectal cancers, promoting a healthy colon.
How fiber diet helps in Diabetes
- High fiber diet benefits metabolic health and is beneficial in type 2 diabetes mellitus, as they are composed of complex carbohydrates that are resistant to digestion and thereby reduce glucose absorption and insulin secretion.
- Soluble type dietary fiber above the ADA (American Diabetes Association) recommended level, improves blood glucose control, lowers plasma lipid concentration and decreases hyperinsulinemia.
- Multiple studies have shown that high Dietary fiber helps in significant reduction in the risk of developing diabetes.
- In overweight or obese patients with T2DM, a low glycaemic-index, high-fiber diet significantly reduces glucose and insulin area under the curve.
- Intake of high fiber, high-carbohydrate, low-GI diets also lessen the risk of increase in serum triglyceride levels
- In a dietary assessment study in urban Asian Indians with Type 2 diabetes mellitus, low consumption of Dietary fiber was associated with higher prevalence of hypercholesterolemia and higher LDL. Fiber-rich foods help to reduce prandial hyperglycaemic deviations, and may also help in reduction of interprandial hypoglycemia in insulin-treated patients. Additionally, Researches show that with moderate increase in fiber intake from food or supplements a significant reduction in fasting plasma glucose and insulin levels, and increased insulin sensitivity even in subjects without diabetes can be achieved.
How to increase dietary fiber in our diet?
Making simple changes in your diet can help you benefit from dietary fiber and maintain good health, preventing chronic disorders. Here’s how you can incorporate fiber into your diet in easy, everyday ways:
– Eat Fruits and Vegetables with Peels: When you eat fruits and vegetables, don’t peel them. The skin or peel often contains a lot of fiber. Apples, pears, and potatoes are great examples. Just wash them thoroughly and enjoy them with their skin.
– Add Beans or Lentils to Salads and Dishes: Some of the excellent sources of fiber are beans, lentils, and legumes. Toss a handful of cooked beans or lentils into your salads. One can also add these to the soups, stews, or pasta dishes. They not only add fiber but also provide protein and make your meals more filling.
– Replace Refined Flour with Millets Flour: Instead of using refined white flour, consider using whole grain flours like millets. Whole grains retain their fiber content. You can find millet flour in many grocery stores nowadays. Use it in making rotis, bakery, cheela preparations, porridges etc,
Remember, these changes might seem small, but they can have a big impact on your health. As a nutritionist at FitandCure, I emphasize the importance of incorporating fiber into your diet. Fiber helps your digestive system work well, keeps you feeling full, and can even lower the risk of heart disease and diabetes. So, enjoy your fruits and veggies with their skin, add beans or lentils to your meals, and opt for whole grain options like millet flour whenever you can. These simple choices contribute to overall well-being and align with FitandCure’s commitment to promoting a healthy lifestyle.