A Fascinating History
Fiber became a household word back in 1970s when Dr. Denis Burkitt, a man nicknamed the Fiber Man, and his colleagues made “the fiber hypothesis” that states that fiber can prevent certain diseases. Through their work in Africa, they discovered that diseases that were common in the Western cultures were not common there. These included heart attacks and high blood pressure (cardiovascular diseases), obesity and diabetes(metabolic disorders), intestinal problems (constipation, diverticulosis, diverticulitis, gallstones, appendicitis,hemorrhoids, polyps, and colon cancer), varicose veins and blood clots (deep vein thrombosis).
The primary dietary difference was the high intake of fiber and low intake of refined carbohydrates in the African population. Burkitt also noted the emergence of these diseases in the United States and England after 1890 following the introduction of a new milling technique that removed fiber from whole grain flour to produce white flour. – Kovacs
Types of Fiber
There are two different types of fiber, soluble and insoluble. As stated in The Benefits of Fiber, by Kathleen Zelman:
- Soluble fibers bind with fatty acids and slow digestion so blood sugars are released more slowly into the body. These fibers help lower LDL (bad) cholesterol and help regulate blood sugar levels for people with diabetes.
- Insoluble fibers help hydrate and move waste through the intestines and control the pH levels in the intestines. These fibers help prevent constipation and keep you regular.
Fiber & Weight Control
Kovacs stated in her article Fiber, that There is some evidence that “bulking up” could lead to slimming down. In a recent study of more than 1700 overweight and obese men and women, those with the highest fiber intake had the greatest weight loss over 24 months. Results from the Continuing Survey of Food Intakes by Individuals (CSFII) from 1994 -1996 also supported the relationship between a high-fiber intake and lower body weight.
- One of the reasons that fiber may have an impact on body weight is its ability to slow the movement of food through the intestines. The gel-like substance that soluble fibers form when they dissolve in water causes things to swell and move slower in the intestines. This increase in time that foods stay in the intestines has been shown to reduce hunger feelings and overall food intake. It has also been shown to decrease the number of calories that are actually absorbed from the ingested food. One study showed an increase in the number of calories that were excreted in the stools when high-fiber psyllium gum-based crackers were given in comparison to low-fiber crackers. Whenever fewer calories are taken in, or more are excreted, weight loss will generally occur.
- Studies show that most people eat about the same weight of food each day, says Barbara Rolls, PhD, author of The Volumetrics Eating Plan. If you choose high-fiber, water-rich foods — such as broth-based vegetable soups, salads, fruits, and vegetables — instead of foods without fiber and water, you can eat the same weight of food but feel full on fewer calories.
The average fiber intake of adults in the United States is less than half recommended levels and is lower still among those who follow currently popular low-carbohydrate diets, such as Atkins and South Beach. Increasing consumption of dietary fiber with fruits, vegetables, whole grains, and legumes across the life cycle is a critical step in stemming the epidemic of obesity found in developed countries. The addition of functional fiber to weight-loss diets should also be considered as a tool to improve success. – Slavin JL.
Fiber & Cholesterol
According to NCEP*, Soluble fiber lowers cholesterol by binding to it in the small intestine. Once
inside the small intestine, the fiber attaches to the cholesterol particles, preventing them from entering your bloodstream and traveling to other parts of the body. Instead, cholesterol will exit the body through the feces.
Soluble fiber appears to be only effective against your LDL cholesterol, so if you also need to lower your triglycerides, or boost your HDL, soluble fiber may not be able to help you with this since the effect can range from very slight to no benefit at all. Additionally, you should not solely rely on fiber to lower your cholesterol, since the effect is only slight (LDL cholesterol can decrease by at most 18%).
*The Natural cholesterol Education Program
Adding Fiber To Your Diet
An article from the famous Mayo Clinic makes it abundantly clear that most people are better off to get their nutrition by eating whole, healthy foods than to take concentrated dietary supplements, especially synthetic ones.
According to The Mayo Clinic, women should try to eat at least 21 to 25 grams of fiber a day, while men should aim for 30 to 38 grams a day. There is a great comprehensive chart (linked here) that shows the amount of fiber per serving that different foods give. In general, legumes, fruits, vegetables, and grains add fiber to a daily diet.