What is Fiber?
Fiber is one of those words discussed frequently without describing or defining what it is. Dietary fiber is indigestible carbohydrates and lignin found in fruits, vegetables, whole grains, and legumes. On the surface this indigestible matter does not appear to have much use – you cannot use for energy and it otherwise has no nutritional value, but there is a link between high fiber diets and lower risks of obesity, diabetes, heart disease, elevated cholesterol, and gastrointestinal disorders.
Types of Fiber
Fiber is classified as soluble or insoluble. soluble fiber dissolves in water forming a gel-like substance. Insoluble fiber does not dissolve in water and passes through the GI tract largely intact increasing movement of other material through the gut and adding bulk to the stools.
The National Academy of Sciences recommend the following amounts of this vital nutrient:
- Men 19 to 50 years old should get 38 grams of daily.
- Men 51 years old and older should get 30 grams daily.
- Women 19 to 50 years old should get 25 grams of daily.
- Women 51 years old and older should get 21 grams daily.
Why should we get this amount fiber for something that just passes through our guts to the toilet? Because fiber is associated with lower risk of chronic disease. The average American gets on 5 to 14 grams of fiber daily.
Fiber and Weight Loss
Studies show that greater weight loss is seen in men and women with the highest fiber intake. It slows the movement of food through the GI tract reducing hunger and overall intake of food. It also decreases the number of calories absorbed as food passes through the GI tract.
Fiber and Diabetes
High fiber diets are associated with lower blood sugar (decreases absorption of sugar) and insulin levels and can help prevent and treat type 2 diabetes. As little as three days of increased roughage intake was shown to improve insulin sensitivity by 8%.
Fiber, Heart Disease, and Cholesterol
Studies show that there a 40% lower risk of heart disease in individuals with the highest fiber intake compare to those with the lowest intake. Consumption of wheat bread is associated with an 11% reduction in fatal heart attacks compared to those who ate white bread. Fiber reduces absorption of dietary cholesterol. High fiber diets can decrease total cholesterol 8% to 26% and LDL cholesterol 5%.
Fiber and GI Disorders
High fiber diets can help prevent hemorrhoids, diverticulosis, diverticulitis, colon cancer, and irritable bowel syndrome. It can help alleviate constipation, too. Lower rates of these diseases may be related to faster transit time of material through the colon, heavier stool weight, and decrease pressure on the walls of the colon. The additional bulk seems to make the colon work more efficiently requiring less pressure to move waste through the large intestine. Hemorrhoids and diverticular disease are related to increase pressures on the colon wall.
Food for Thought
Fiber is generally removed from prepackaged foods/meals making them easier to freeze and transport. Many of these prepackaged foods are low in fat. Low fat foods have little taste. To enhance the taste sugar is added. The combination of low fiber and high sugar is not healthy. It minimizes the absorption of sugar. In nature wherever you find natural sugars (mainly fruits) in foods you will also find fiber.
What can fiber do for you? As it turns out, it can improve your health greatly. Be sure to get enough of this essential “nutrient”in your diet.