Nutritional Management of Type 2 Diabetes

There are three major types of diabetes mellitus: type 1, type 2, and gestational. All types of diabetes are characterized by abnormally high blood glucose levels, or fasting levels of 126 mg/dL (7m mol/L) or higher. People with diabetes are considered to be “carbohydrate intolerant” because carbohydrate consumption tends to raise blood glucose levels. Type 1 diabetes is carbohydrate intolerance resulting from destruction of insulin-producing cells of the pancreas. Individuals with type 1 diabetes require an external supply of insulin. It is considered an autoimmune disease. About 10% of cases of diabetes are of this type. Type 2 diabetes is carbohydrate intolerance due to the body’s inability to use insulin normally, to produce enough insulin, or both. About 90% of cases of diabetes are of this type. Gestational diabetes is carbohydrate intolerance that begins or is first recognized during pregnancy. It is closely related to type 2 diabetes.

Some people with type 2 diabetes can manage their glucose levels with diet and exercise, whereas others will need an oral medication that increases insulin production or sensitivity, or insulin to further boost glucose absorption into cells. Individualized diet and exercise recommendations and an educational and follow-up program developed and implemented by registered dietitians, certified diabetes educators (CDE), physicians, and nurses are preferred for diabetes management. Carefully planned and monitored dietary recommendations are a major component of the management of type 2 diabetes. Individual blood glucose levels vary a good deal in response to diet composition, so dietary prescriptions must be tailored for every person. For patients with type 2 diabetes, the American Diabetes Association’s guidelines recommend:
●Weight loss of 7% of body weight or more
● Percent of total calories from the energy nutrients: 15–20% protein, <30% fat, and approximately 50% carbohydrates
●Percent of total calories from saturated fat: <7%
●Percent of total calories from trans-fat: as low as possible
● Restriction of cholesterol intake to 200 mg per day or less
●14 g fiber per 1000 calories of food intake
● Whole grains should comprise half of all grain intake
● Low glycemic-index foods that are rich in fiber and other important nutrients should be encouraged
There is no evidence to support prescribing diets such as “no concentrated sweets” or “no added sugar.” Sucrose can be substituted for other carbohydrate foods in meal plans. Restrictions on food choices for people with diabetes should only be implemented when indicated by scientific evidence.
Glycemic Index - Glycemic index (GI) is a measure of the extent to which 50 grams (about 13⁄4 ounces) of carbohydrate- containing foods raise 2-hour postprandial blood glucose levels compared to 50 grams of glucose or white bread. Not all expert committees on diabetes recommend the use of low-GI foods as a primary strategy in the dietary management of diabetes. However, mounting evidence indicates that low-GI diets are beneficial for the control of blood glucose and insulin levels. Diets that provide low-GI carbohydrates and approximately 30 grams of fiber daily are associated with reduced blood levels of glucose, insulin, and triglycerides versus lower-fiber (15 g/day), high-GI diets. Foods with high GI raise blood glucose and insulin levels more than do foods with low GI, and high-GI foods lead to more episodes of hyperglycemia (high blood glucose level) than do diets pro- viding mainly low-GI carbohydrates.
It is currently recommended that low-glycemic index foods rich in fiber and other important nutrients be included in the diets of individuals with diabetes.