High fiber diet is generally low in sugar and fat content and therefore it has low calorie content. Low digestibility of fiber components in the small intestine by the mammalian enzymes also results in lower calorie intake from the diet. Furthermore, in high dietary fiber diet the overall digestibility of fat and protein, both calorie sources, is reduced.

Associations between high fiber intake and lower incidence of human diseases, such as coronary heart disease, diabetes, and bowel diseases, are mostly based on observational studies. Nonetheless, decades of studies, such as by Dr. Walker of South African Institute for Medical Research and the Late Dr. Trowell, support the importance of high fiber food in the prevention of many of the diseases, sometimes known as Western diseases. According to a review of studies by Dr. Walker, incidence of obesity, hypertension, diabetes, coronary health disease (CHD), appendicitis, diverticular diseases, cancers of the breast and colon, and osteoporosis are lower among vegetarians and Seventh Day Adventists (because of their high fiber diet) than the diet of omnivorous eaters.

High fiber diet (fruits, vegetables, and whole grain based diet) is associated with low serum low-density lipoprotein (LDL) cholesterol and total cholesterol and general decrease in risks of cardiovascular disease. Even though, the health benefit from high fiber foods is multifaceted, soluble fiber is among the factors that helps reduce serum total and low-density lipoprotein cholesterol levels. An example of good source of soluble fiber known to reduce serum total and low-density lipoprotein cholesterol levels is flax seed.

In summary, health benefits of consumption of high fiber diet include:

• Lower Type 2 diabetes risk.
• Lower blood (serum) cholesterol level.
• Lower coronary heart disease (CHD) risk.
• Contain high content of antioxidants that fight cellular damage, diseases and aging.
• Reduce inflammatory bowel diseases (irritable bowel syndrome) such as Crohn’s disease, diverticulitis and perhaps ulcerative colitis), hemorrhoid, and constipation.
• Alleviate age-related diseases such as cancer and dementia
• Aid in weight loss