Diet lentils and beans

Published on March 8th, 2013 | by George Conte


Dietary fiber benefits and sources

Dietary fiber is an umbrella term that includes plant substances not cleaved by the human gastrointestinal enzymes. Only a few bacteria and fungi and some species of insects and snails can deconstruct these plant fibers.

From a chemical point of view dietary fiber belongs to polysaccharides. One of the main characteristics of polysaccharides is the capacity to trap water molecules and swell.
Depending on the degree of water absorption from the dietary fiber molecules, fibers can be classified into two major groups:

Insoluble fiber

Insoluble dietary fibers are cellulose, hemicelluloses and lignin. In this group belong polysaccharides with low molecular weight. These fibers can be expelled from the intestine almost unchanged.

Soluble fiber and benefits

Soluble dietary fibers are gums and pectins. Such fibers contain a large percentage of polysaccharides with high molecular weight. The particle size of the polysaccharide and the appropriate configuration give the ability to entrap large number of water molecules resulting in a gelatinous texture.

Because of that particular texture the soluble dietary fibers present interesting physiological actions and benefits for our health. Soluble dietary fibers can:

  • Reduce blood cholesterol. The gelatinous substance resulting from the soluble dietary fiber in the gut binds bile salts. In response to this action, LDL-cholesterol is transferred from the blood to the liver and is converted to bile salts in order to replenish those eliminated by soluble dietary fibers.
  • Limit the growth levels of post meal glucose. Fibers can slow down digestion and absorption of glucose in the blood thereby preventing the rapid post meal increase in glucose levels.
  • Cause delayed gastric emptying because of extended digestion.
  • Reduce the risk of cancer. Fermented in the colon and the products of fermentation contribute to the microflora balance of the gut (prebiotics). Products of anaerobic fermentation are fatty acids with a few carbon atoms such as butyrate and acetate. ¬†There are indications that butyric acid prevents the development of colon cancer and colitis.

Potential negative effects from excessive consumption of dietary fiber

Some of the negative effects include reduced absorption of vitamins, minerals and proteins. The anaerobic fermentation of soluble dietary fibers in the small intestine leads to gas production such as carbon dioxide and methane which cause dilation of stomach and discomfort. To avoid such effects, it is suggested for a daily dietary fiber intake to be from 20g. to 35g. Any differentiation from those limits will cause other problems.  Also children and elderly should follow a lower daily consumption.

Fiber rich foods

Almost all foods of plant origin contain both types of dietary fibers. Soluble dietary fibers are contained in relatively large percentages in dried beans, oats, barley, and some fruits and vegetables.

Great dietary fiber sources (per 100 grams servings) are:

Source Grams of dietary fiber
chia seeds, dried 38g
Lentils, raw 30g
Cereals 29g
Seeds, flaxseed 27g
Beans, yellow, mature seeds, raw 25g
oatmeal 10g
Raspberries, raw 6g
broccoli 3g
Apple with skin, raw 2g

Final thoughts

The daily consumption of appropriate amounts of dietary fibers has many advantages for our health and for weight loss as you can tell by now. Proper dietary fiber intake is one of the most important factors of a healthy, balanced and successful diet plan.

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About the Author

George Conte is a student of Nutrition and Dietetics, a fitness and healthy living enthusiast. After seven years of personal experience with weight loss, exercise and a total body transformation where he managed to burn 121+ pounds of fat he became the founder of A website dedicated to help you overcome obesity and transform your life the same way he did!

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