Because of the important physiological effects of dietary fiber, a diet low in fiber obviously leads to altered physiology or diseases. The diseases with the strongest correlation to a lack of dietary fiber are diseases of the colon and gastrointestinal tract, heart disease, obesity, and diabetes.
Diseases of the Colon and Gastrointestinal Disorders: The data documenting the protective effect of dietary fiber on colon cancer is well-known. There is evidence for similar strong links with other common diseases of the colon: diverticulitis, diverticulosis, irritable bowel syndrome, ulcerative colitis, and appendicitis as well as hemorrhoids, peptic ulcers, and hiatal hernia.
Heart Disease: Increasing fiber intake is a safe and inexpensive dietary strategy to reduce the risk of heart disease. High intake of dietary fiber is known to reduce the total cholesterol and triglyceride levels while increasing the HDL cholesterol level.
Obesity: A diet deficient in dietary fiber is an important cause of obesity. Dietary fiber plays a role in preventing obesity by:
- Increasing the amount of necessary chewing, thus slowing the eating process
- Increasing the fecal caloric loss
- Improving control of blood sugar
- Inducing satiety (the feeling of fullness)
Diabetes: Population-based studies clearly show Type 2 diabetes to be one of the diseases most clearly related to inadequate intake of dietary fiber. Clinical trials have demonstrated the beneficial therapeutic effect on diabetes of increased dietary fiber through diet and/or supplementation. Soluble fiber sources significantly outperform insoluble forms in this application