Nutrition Paper on Fiber and Type II Diabetes: Mechanisms and Health Benefits


Dietary fiber intake has numerous health benefits. Nevertheless, the average fiber consumptions for most United States families are below half of the commended levels. People with high intakes of dietary fiber are at a lower risk for acquiring diabetes. Soluble fiber from psyllium is a prospective natural dietary supplement for consumption in nutritional rehabilitation of type 2 diabetic patients since it is cheaper and produces positive results within a short time. High intake of soluble fiber enhances glycemia and insulin sensitivity in diabetic patients and those who do not have diabetes. The commended dietary fiber intakes for kids and older people are 14g/1000kcal.

Key Words: Dietary fiber, type 2 diabetic mellitus, glycemic control and plasma cholesterol


Fiber and Type II Diabetes: Mechanisms and Health Benefits


Diabetes mellitus has become a major health problem in the United States. In addition, fiber has been examined in treating diabetes for many years because high-fiber content reduces the glycemic index of foods. Therefore, reduced glycemic index causes smaller increases in blood glucose, leading to minimal blood glucose and HbA 1c. Although high-fiber intake is associated with a lower risk of diabetes, the proof of fiber consumption and regulation of diabetes is not clear. Several studies on fiber intake and glycemic management indicate enhanced diabetic control while others do not. Patients of diabetes mellitus are encouraged to take many vegetables fruits, and grains, which contain high dietary fiber. There should be a moderate increase in the consumption of dietary fiber each day due to the cholesterol-lowering effects of soluble fiber (Chandalia et al., 2000). In addition, it is challenging to attain a high dietary intake of soluble fiber without consuming foods or supplements enriched with fiber (Post et al., 2012). This paper studies the impact of increased consumption of dietary fiber on glycemic regulation and plasma lipid concentrations in patients with type 2 diabetes. The paper also examines the impacts of the intervention on the intestinal absorption of cholesterol and fecal excretion of sterols as a way of uncovering the mechanisms by which a high-fiber diet decreases plasma cholesterol.


Diabetes is the rapid increasing chronic condition worldwide. The centers for Disease Control and Prevention (CDC) states that 9.3 % of the U.S. population has diabetes. The number of individuals with diabetes is projected to rise from 387 to 592 million globally by 2035 (Abutair, Naser & Hamed). Diabetes also raises the chances of severe complications like heart diseases and related deaths. Diet, exercise, and behavioral methods are significant in managing and preventing diabetes. More significantly, the consumptions of dietary fibers are inversely related to type 2 diabetes. Studies indicate that taking more than 26g a day lowers the danger of developing type 2 diabetes by 18% compared to individuals with the lowest intake (Chandalia et al., 2000).


Dietary fiber is considered a vital component in healthy eating. Dietary fibers are a great collection of multifaceted saccharides-based molecules that can be potential nutrients of nutrient antecedents to avert their absorption. Dietary fibers prevent and alleviate type 2 diabetes mellitus. In addition, they minimize the risk of hyperlidemia, hypercholesterolemia, and hyperglycemia through moderating food ingestion, digestion, absorption, and metabolism. Dietary fiber consumption has several health benefit and increased consumption minimizes the danger of developing diabetes. It also enhances serum lipid concentrations, reduces blood pressure, improves blood glucose control in diabetes, enhances regularity, assists in losing weight, and improves the immune function (Anderson et al., 2009).

Fiber is usually categorized as soluble, which dissolves in water or insoluble, which does not dissolve. The sources of soluble fiber are apples, oats, beans, peas, citrus fruits, psyllium, and barley (Abutair, Naser & Hamed, 2016). Psyllium is a water-soluble fiber obtained from the pods of disposed seeds from Plantago Ovate, which enhances glycemic management, proper body weight, and bowel movement in patients with type 2 diabetes. However, increased intake of high glycemic index food is linked to insulin resistance and high occurrence of metabolic disorder in patients with type 2 diabetes (Abutair, Naser & Hamed, 2016).




Diabetes Prevention and Management: Role of Fiber


Increased levels of dietary fiber consumption are related to a noteworthy decline in the occurrence of diabetes based on estimations for probable cohort epidemiological studies. Therefore, increased dietary fiber intake performs an important protective function with respect to diabetes that also depends on several dietary factors. The Finnish Diabetes Prevention Study provided randomized controlled trials (RCT) whereby people with the highest level of fiber intake had a 62% reduction in progression of prediabetes to diabetes over 4.1-year duration, in comparison to individuals with the minimal fiber intake (Abutair, Naser & Hamed, 2016).

One method through which a high- fiber diet may be defensive against diabetes and obesity entails intestinal bacteria’s capability to ferment fibers. The bacteria in the intestines ferment foods high in fermentable fibers like beans, cabbage, and vegetables into short-chain fatty acids (SCFAs). The acids are concerned with producing sugar. According to researchers, glucose has particular components that are sensed by nerves situated in the vein that gathers blood from the intestines called portal wall. A nerve signal is then conveyed to the brain, which triggers a sequence of protections against diabetes and obesity in response to the signal (Abutair, Naser & Hamed, 2016).

Glycemia and Insulin Sensitivity

Increasing the consumption of fiber for people with type 2 diabetes is linked to substantial improvements in glycemic control and reductions in the utilization of oral medication and insulin doses. Raising dietary fiber consumption without changing the energy intake from carbohydrates, proteins, or fats considerably enhances regulation of glycemic and minimizes the need for medication and insulin in people with type 1 and 2 diabetes. The metabolic disorder, which is a group of defects like insulin resistance, dyslipidemia, visceral adiposity, and hypertension can be improved and reversed by increased dietary fiber. Short-term investigations indicate that dietary fiber intake reduces postprandial glycemia and insulinemia and improves insulin sensitivity.

Nutritional Fiber Commendations for Diabetic Persons

General nutrition guidelines for individuals with diabetes from nine powerful international organizations were recently revised and combined as “Evidence-Based Recommendations” (Anderson et al., 2009, p. 193). The guidelines are:

  • Reaching and retaining desired weight.
  • Regulating intake of carbohydrates to 55-65g of energy
  • Selecting whole grains, legumes, and vegetables
  • Utilizing fruits and other sources of mono-disaccharides in moderation
  • Incorporating GI into exchanges and teaching material and
  • Regulating other intake levels (Anderson et al., 2009, p. 193).

Since about 80% of type 2 diabetic people are obese, weight loss and control should be highly considered in their management. High fiber intake has valuable effects on weight management, hence, increased consumption of high-fiber foods or supplements need to be effected.

The U.S. dietary guidelines recommend that adults need to take 20-30 grams of fiber each day. A perfect amount for many individuals is about 50 grams per 1000 calories taken. However, the majority of individuals consume only half or less. According to a new study carried out by researchers at the Imperial College London, Individuals who had the highest consumption of fiber (above 26 grams a day) had an 18% reduced risk of developing type 2 diabetes compared to those  with the lowest intake (less than 19 grams a day) (Abutair, Naser & Hamed, 2016).

Fiber benefits diabetes patients by changing hormonal signals, slowing nutrient absorption or changing fermentation in the large intestine as well as enhancing feelings of satiety. Consuming a high-fiber diet is also related to weight loss, which can in turn decrease the diabetes risk. When the participants’ BMI was accounted for, the advantages of a high-fiber diet vanished, which implied that they arose from the fiber’s function in retaining a healthy weight.

The Best Fiber for Diabetes

Although cereal and vegetable fiber reduces the diabetes threat by 19% and 16% correspondingly, fruit fiber has no this benefit. Individuals are not supposed to depend on cereal or other grains as their source of fiber since complete-grain breads cereals, pasta, and other kinds of grains have non-fiber carbohydrates (sugar and starch) besides fiber. Though the fiber does not rise the blood sugar levels because the body breaks it down, grains rise insulin and leptin levels, which are the main cause of many chronic illnesses, including type 2 diabetes (Post et al., 2012).


About a half of the United States populace has diabetes, prediabetes, or the metabolic condition related to high risk for the development of diabetes. Individuals with high levels of dietary fiber consumption, in comparison to the ones with minimal consumption, seem to have a 29% low risk for suffering from diabetes. Three RCTs showed that moderate increases in dietary fiber intake are related to enhanced fasting glycemia and insulinemia and high insulin sensitivity for individuals without diabetes. Several RCTs of diabetic individuals indicate that a normal rise in fiber consumptions enhances glycemic control. Increased consumption of fiber from high- fiber foods or supplements can highly improve serum lipoproteins and blood pressure, including assisting in weight management for diabetic people (Anderson et al., 2009).

The consumption of dietary fiber among individuals living in Western nations is low and according to the Third National Health and Nutrition Examination Survey (NHANES), it is around 17g each day in the United States. Though patients with diabetes are encouraged to raise their consumption of dietary fiber, NHANES observation indicates that they averagely take only 16g a day. Increased fiber diet enhances glycemic control and lowers urinary glucose elimination. Furthermore, increased fiber-diet also reduces glycosylated hemoglobin amounts and 24-hour plasma insulin concentrations moderately. Patients can also attain an increased intake of dietary soluble fiber by consuming unfortified foods. Therefore, patients with diabetes should be advised to use fortified foods rather than less edible distilled-fiber meals and supplements to rise their consumption of dietary fiber (Anderson et al., 2009).

The mechanisms of improved glycemic control linked to increased fiber intake are not defined. It is not certain whether the effect is a consequence of risen soluble fiber, insoluble fiber or both. Besides causing increased fecal elimination of bile acids, dietary fiber can lead to malabsorption of fat. Dietary fiber also enhances glycemic control by minimizing or slowing the absorption of carbohydrates (Chandalia et al., 2000).

A high-fiber diet decreases plasma overall cholesterol intensities by 6.7%. Thus, low cholesterol can be associated with an average rise of 17g in the intake of soluble fiber. In addition, reduced plasma triglyceride and VLDL cholesterol concentrations in a high-fiber diet may be a result of improved glycemic control. However, the mechanisms of the decline in plasma cholesterol intensities resulting from high dietary fiber intake are contentious. Increased bile-acid excretion explains most of the reductions, and reduced cholesterol absorption may also lead to this finding. Several studies have reported a variable rise in bile-acid elimination caused by intake of pectin, oat bran bagasse, and foods with a mixture of soluble and insoluble fiber (Chandalia et al., 2000).

When applied as a remedy in patients with type 2 diabetes mellitus, high dietary fiber improves fasting blood glucose and HbA1c. Metformin, an oral medication utilized in treating diabetes, shows HbA1c reductions from a range of 0.2% to 2%. However, introducing changes in diet to minimize HbA1c by around 0.3% is significant as an adjunctive therapy to medication as part of a general treatment strategy for controlling diabetes. High- fiber forms of traditionally low-fiber foods are acceptable for patients with type 2 diabetes. Dietary fiber intake from several sources is linked to a significantly reduced risk of coronary cases in epidemiologic examinations in patients with diabetes. It is important to note that more than 20g of fiber consumption is associates with a low risk for a coronary heart disease among women (Post et al., 2012).


Increased consumption of dietary fiber, especially the soluble one, by patients with type 2 diabetes mellitus enhances glycemic control and reduces hyperinsulinemia. It also lowers the plasma lid concentrations. Therefore, nutritional plans for patients with diabetes should stress on general increase in dietary fiber by taking unfortified foods instead of using fiber supplements. In addition, increasing dietary fiber in the meals of patients with type 2 diabetes is helpful and it should be fostered as a diseases management plan. Generally, the intervention entailing fiber supplementation for type 2 diabetes mellitus can decrease fasting blood glucose and HbA1c. The investigations that entail larger doses of fiber assist in supporting present diabetes dietary fiber recommendations. Current researches indicate that the average consumptions of dietary fiber for adults in the U.S. are below half of the commended levels. Therefore, fiber supplement producers, food manufacturers and health agencies should collaborate and teach consumers about the health benefits of dietary fiber consumption from various supplements and foods.




Abutair, A. S., Naser, I. A. & Hamed, A. T. (2016). Soluble fibers from psyllium improve glycemic response and body weight among diabetes type 2 patients (randomized control trial). Nutrition Journal15(1), 86.

Anderson, J. W. et al. (2009). Health benefits of dietary fiber. Nutrition reviews67(4), 188-205.

Chandalia, M., Garg, A., Lutjohann, D., von Bergmann, K., Grundy, S. M. & Brinkley, L. J. (2000). Beneficial effects of high dietary fiber intake in patients with type 2 diabetes mellitus. New England Journal of Medicine342(19), 1392-1398.

Post, R. E., Mainous, A. G., King, D. E. & Simpson, K. N. (2012). Dietary fiber for the treatment of type 2 diabetes mellitus: a meta-analysis. The Journal of the American Board of Family Medicine25(1), 16-23.