Posted on August 5, 2010 - No Comments
Obesity is a disease associated with a low fiber diet, and even if we are only looking to shed a few unwanted pounds, it serves us well to understand the relationship between fiber and fat.
Dietary fiber aids in preventing obesity through a number of different mechanisms. It slows the eating process by increasing the amount of chewing necessary. It improves digestive secretions, allowing one to obtain more nutrients from less food. It induces a state of satiety (a feeling that one has eaten enough to be satisfied.) This effect can also be obtained with supplemental fiber, taken with water before meals. This forms a gelatinous mass in the stomach making the individual feel full, and thus less likely to overeat.
An added benefit of fiber in weight loss programs is its ability to help control blood sugar levels. Soluble fibers delay gastric emptying, which slows the absorption of glucose. Stable blood sugar prevents the tendency of refined carbohydrates in the diet to be stored as fat in the body.
Fiber is classified as either soluble (i.e. water-soluble) or insoluble. Insoluble fibers (e.g. wheat bran) mostly enhance stool bulk, weight and transit time. In other words, help to keep us “regular.” Soluble fiber (e.g. Oat bran) is the kind that aids in lowering cholesterol levels. The following studies are based on using soluble fiber, but since obesity is usually accompanied by congestion of the bowel, insoluble fiber is also important to ingest.
In a study done with a soluble fiber, women were given 10 grams of guar gum just before lunch and dinner. Participants did not alter their normal eating habits. The women averaged a pound per week in weight loss after 2 months on the program. (Their cholesterol and triglyceride levels also decreased.) In another study involving 14 subjects over 4 weeks, citrus pectin (a soluble fiber) was administered at 5.5 grams per day, along with calorie restrictions. The average weight lost was 12 pounds. (Insoluble fibers show much the same effect, but seem to require more time to achieve the same results.) This study showed the best results out of a series of studies.
A review of related studies done at Tuffs University in Boston suggested more realistic results. Anyone should be able to lose at least 4 lbs over 4 months by simply adding an additional 14 grams of fiber per day to their diet (either from food or supplementation.) While this might not seem very impressive, remember that the total fat loss will compound over a year to a reasonable level that has been attained safely and painlessly. And if one maintains this dietary change (i.e. increased fiber levels) it is unlikely there will be any rebound effect. Basically, a diet supplemented with fiber can increase weight loss by 50 to 100% over just simple calorie restriction.
The American National Cancer Institute recommends 20 to 30 grams of total fiber per day, ideally a mix of soluble and insoluble, for general health and well-being. North Americans consume an average of 15 grams of fiber per day. In some countries (e.g. Greece) people eat about 50 grams per day. The best forms of supplemental fibers for long-term regular usage include flax meal, oat fiber, pectin, and inulin.
The aforementioned guar gum is restricted for use as a supplement in Canada due to a death caused by improper use. We suggest the use of inulin (derived from chicory) as a supplemental soluble fiber, a much safer substance with a much broader range of benefits than guar gum. Always remember to take in adequate amounts of water when using any fiber supplement, especially in pill form. Because fibers are fermented in the intestines (which serves to produce other beneficial effects such as increasing friendly bacteria,) one should start out with a small dose and gradually increase it. One might otherwise experience flatulence and abdominal discomfort. Begin with about 2 grams before meals 2 or 3 times per day, gradually working up to 5 grams per serving.
Acquiring a book that lists the fiber content of foods would be helpful. Some examples: