In the past few years fiber became the “buzz” word of every newly created weight loss or a healthy eating diet on the market. Finally the significant role that fiber plays in our health is beginning to be understood. But for some, this type of a carbohydrate is still a mystery. To help you out, this article defines what is fiber and looks at the benefits of fiber in a diet, the actual reasons for “all that buzz”.
What Is Fiber
Dietary fiber is a complex carbohydrate. In nature, it is a structural part of a plant. It is found in all plant food in various amounts, and often within the edible part of a plant that is indigestible by our digestive system. Fiber includes:
- cellulose – found in all fruits, vegetables and legumes
- hemicellulose – a main component of cereal fiber
- pectins – found in fruits and vegetables; high quantity of pectin is found in citrus fruits, hence the importance of lemons in making jams
- gums and mucilages – psyllium plus others that are added by food manufactures to processed foods to stabilize them
- lignin – found in the woody parts of the plant
Classification Of Dietary Fiber
Dietary fiber can also be classified on the basis of its solubility in water. It is classified into two groups, it is either soluble or insoluble in water. Most plants provide both forms of this carbohydrate.
Although it is indigestible, the soluble form dissolves in water to form a gel during digestion. It is an essential dietary component that helps maintain good health, as it helps to slow digestion, nutrient absorption and it helps maintain regularity. This form of fiber includes pectins, gums and mucilages and some hemicelluloses.
Sources of Soluble Dietary Fiber
It is found in all plant foods at different quantities. The main fiber-rich categories of food are listed below:
- legumes (peas, soybeans, lentils, beans)
- oats, rye, barley,
- some fruits and fruit juices, including the meat of apples and pears, plums, prunes (prune juice), berries (raspberries, strawberries, blueberries, etc)
- root vegetables and tubers, onions
- psyllium seed husk
Please note that some plants/foods listed in this list also contain insoluble fiber. For example, the meat of an apple contains soluble fiber such as pectin and its skin contains insoluble fiber.
It is also found in the edible part of a plant, but unlike soluble one it does not dissolve in water. It is often referred to as “roughage”. It absorbs water as it moves through the intestines. This results in softer stools and helps maintain regularity.
Sources Of Insoluble Dietary Fiber
- whole grain foods, wheat, corn, bran
- seeds (for example flax seeds)
- skins of some fruits, such as apple, tomato, plums
- potato skins
- certain vegetables, for example cauliflower, string beans, pea pods, celery, zucchini
- some fruits like avocado, bananas
Benefits Of Fiber In A Diet
As I briefly mentioned already, benefits of this nutrient in a diet are numerous. For a long time people knew that it keeps bowel movements regular. But this healthful effect was not taken overly seriously and consumption of fiber-rich foods was generally neglected. In recent years scientists assigned dietary fiber numerous health benefits and that resulted in its recent popularity. Some of the benefits of its consumption include:
- delay of glucose absorption – benefits diabetes, prevents obesity, aids weight loss
- lowering of blood cholesterol – benefits heart disease
- keeping you satiated (less hungry) – prevents obesity and helps you lose weight
- promotes bowel movements
- benefits digestive disorders
- possibly reduces the risk of developing some cancers, including colon cancer (source)
Daily Fiber Requirement
On average, North Americans consume less than 50% of the dietary fiber levels recommended for good health. In the preferred food choices of today’s youth, this value may be as low as 20%, a factor considered by experts as contributing to the obesity levels seen in many developed countries (Source)
Experts have recommended that women eat about 25 – 30 grams of fiber per day. Men should consume 38 grams each day. After the age of 50 the amount of fiber should be reduced to 20 grams for women and 30 grams for men.
According to the World Health Organization the upper daily limit of this important nutrient should not exceed 40 grams. The reason is, that despite its benefits, when eaten too much it can cause discomforts such as bloating, gas, diarrhea and even blockage of the gastro-intestinal tract. As well, to much fiber may interfere with absorption of minerals.
In summary, you’ve learned what fiber is and got an idea of health benefits of fiber in a diet. To maintain good health and manage your weight you should eat as much of it as the daily recommendations suggest. To help you out, you can find out all about the best high fiber foods here.