The most fundamental component of the diabetes treatment plan for all patients with type II diabetes is medical nutrition therapy. Specific goals of nutrition therapy in type II diabetes are to:1 Achieve and maintain as near-normal blood glucose levels as possible by balancing food intake with physical activity, supplemented by oral hypoglycemic agents or insulin (endogenous or exogenous) as needed Normalize blood pressure Normalize serum lipid levels Help patients attain and maintain a reasonable body weight (defined as the weight an individual and health-care provider acknowledge as possible to achieve and maintain on a short- and long-term basis) Promote overall health through optimal nutrition and lifestyle behaviors. Because no single dietary approach is appropriate for all patients, given the heterogeneous nature of type II diabetes, meal plans and diet modifications should be individualized to meet a patient’s unique needs and lifestyle.
Accordingly, any nutrition intervention should be based on a thorough assessment of a patient’s typical food intake and eating habits and should include an evaluation of current nutritional status. Some patients with mild-to-moderate diabetes can be effectively treated with an appropriate balance of diet modification and exercise as the sole therapeutic intervention, particularly if their fasting blood glucose level is < 200 mg/dL. The majority of patients, however, will require pharmacologic intervention in addition to diet and exercise prescriptions. It is important to note that no pharmacologic treatment will be successful if the patient is not on some type of dietary and exercise regimen. Dietary changes do not have to be dramatic to produce clinically important results in terms of lowering blood glucose and lipid levels.
Regular monitoring of blood glucose, glycated hemoglobin, lipid levels, blood pressure, and body weight serves as an ongoing assessment of the nutrition intervention. Nutrition ConsultBecause nutrition issues and meal planning are complex, a registered dietitian who is familiar with the current principles and recommendations for managing diabetes may be consulted after a patient is diagnosed with diabetes. This health-care professional can be an essential member of the diabetes management team and performs valuable functions: Conducts initial assessment of nutritional status: Diet history Lifestyle Eating habits Provides patient education regarding: The basic principles of diet therapy for diabetes Meal planning Problem-solving techniques for changing eating behaviors Develops an individualized meal plan: Emphasizing one or two priorities Minimizing changes from the patient’s usual diet (to encourage compliance) Provides follow-up assessment of the meal plan to: Determine effectiveness in terms of glucose and lipid control and weight loss Make necessary changes based on weight loss, activity level, or changes in medication Provides ongoing patient education and support (particularly for those on weight-loss regimens), helping patients learn to adjust their meal plans for various situations. Body Weight Considerations Weight loss frequently is a primary goal of nutrition therapy because 80% to 90% of people with type II diabetes are obese. 2} Caloric restriction and weight loss, even as small as 5% to 10% of body weight, can result in: Improved glucose control Increased sensitivity to insulin Lower lipid levels and blood pressure The need for a corresponding lowering of the dosage of pharmacologic agents (eg, oral hypoglycemic medications and insulin). Weight loss is associated with improved glucose uptake and insulin sensitivity as well as decreased hepatic glucose production.
Consequently, the therapeutic regimen most useful for individuals with obesity and glucose intolerance is weight reduction via nutrition therapy and increased physical activity. If moderate weight loss does not improve metabolic parameters, however, pharmacologic therapy (oral hypoglycemic agents or insulin) may need to be added to the regimen. Weight loss and subsequent weight maintenance can be the most difficult and challenging aspect of managing diabetes. Therefore, emphasis should be placed on achieving and maintaining normal blood glucose control as the goal of nutrition therapy, using nutritionally balanced meal plans that promote gradual weight loss as a means to achieve this metabolic goal. A reasonable approach that provides a combination of the following strategies increases the chances of a successful outcome: Modest caloric restriction Spreading caloric intake throughout the day Increased physical activity Behavior modification techniques for changing eating habits and attitudes and promoting healthy, long-term lifestyle behaviors Psychosocial support. Suggested weights for adults based on the USDA Dietary Guidelines for Americans (1990) are shown in Table 5.1.
The upper end of the ranges are considered appropriate weights for men, given their greater bone and muscle mass; the lower end of the ranges are for women, who have comparatively less bone and muscle mass. Approximately 10% of patients with type II diabetes are of normal weight and do not need to modify their caloric intake. For these individuals, nutrition therapy focuses on distributing calorie and carbohydrate intake throughout the day to achieve optimal glucose control.
The pattern of spreading out calories and carbohydrates between meals and snacks is individualized based on results of self-monitoring of blood glucose. Calorie IntakeAdult calorie needs vary according to age, activity level, and desired weight change. The following procedure can be used to determine adult calorie requirements. First calculate desired body weight: Women: 100 lb for the first 5 ft of height plus 5 lb for each additional inch over 5 ft Men: 106 lb for the first 5 ft of height plus 6 lb for each additional inch over 5 ft Add 10% for larger body builds; subtract 10% for smaller body builds.
Then, multiply the resulting weight by one of the following to compute calorie need based on desired weight: Men and physically active women: multiply by 15 Most women, sedentary men, and adults over age 55: multiply by 13 Sedentary women, obese adults, sedentary adults over age 55: multiply by 10. If weight loss is indicated, daily calorie intake needs to be adjusted to produce the necessary deficit.
Given that a 3500-calorie deficit per week is required to produce a 1-pound loss of fat, a decrease of approximately 500 to 1000 calories per day is needed to lose 1 to 2 pounds of fat per week. Regular exercise is an excellent way to create a calorie deficit and has been associated with successful weight maintenance. Because calorie restriction alone can be difficult to maintain, some people have greater success by eliminating 250 to 500 calories from their daily diet and increasing daily activity by 250 to 500 calories. Nutrient Composition of the DietA nutritionally balanced diet is as important for individuals with diabetes as for nondiabetics.
Diet prescriptions for those with type II diabetes need to take into account the higher prevalence of hyperlipidemia, atherosclerosis, and hypertension in this population. Protein Intake The Recommended Dietary Allowance (RDA) for adults as advised by the USDA is used as the guideline for protein intake for patients with type II diabetes (0. 8 g/kg body weight/day). This equates to a small-to-medium portion of protein once daily with either breakfast, lunch, or dinner. Protein allowance therefore amounts to 12% to 20% of daily calories and should be derived from both animal and vegetable sources. Vegetable protein may be less nephrotoxic than animal protein and thus restriction of vegetable protein may not be necessary. In following these recommendations, meat, fish, or poultry consumption would need to be limited to 3 to 5 oz daily.
Because excessive protein intake may aggravate renal insufficiency, type II patients with evidence of nephropathy should be encouraged to limit their protein intake to 12% of daily calories. In short-term studies, more severe restriction of protein (0. 6 g/kg body weight/day) has been shown to be effective in slowing the progression of kidney disease in patients with diabetes who already have some renal insufficiency, but has been reported to be associated with loss of muscle mass and strength. In addition, evidence exists that a low-protein diet can reverse the rate of deterioration in renal function.
Fat Intake The remaining 80% to 90% of daily calories are distributed between fat and carbohydrate intake, based on a patient’s nutrition assessment and treatment goals (glucose, lipid, and weight outcomes). Several important benefits support the restriction of dietary fat in patients with type II diabetes: Excess consumption of dietary fat may contribute to obesity, which is common in the majority of patients with type II diabetes. Restricting dietary fat may limit the development or reduce the extent of obesity. Abnormal lipid levels often are associated with both obesity and diabetes and increase the risk of cardiovascular disease.
Reduced intake of saturated fat can have beneficial effects by reducing triglyceride and low-density lipoprotein (LDL) cholesterol, and increasing high-density lipoprotein (HDL) cholesterol. Therefore, the following guidelines are recommended for fat intake to promote weight loss, achieve lipid goals, and reduce cardiovascular risk: Reduce dietary fat to < 35% of total calories Limit saturated fat to < 10% of total calories, and < 7% of calories in patients with elevated LDL cholesterol Limit polyunsaturated fats to 10% of total calories Limit daily cholesterol consumption to 300 mg Moderately increase intake of monounsaturated fats such as canola and olive oil (up to 20% of calories).
A diet high in monounsaturated fats has been shown to improve glucose control, lower triglycerides, and raise HDL levels. Effectiveness of dietary fat modification is determined by regular monitoring of glycemic control, triglyceride and cholesterol status, and body weight, with periodic adjustments based on metabolic response to the diet. Carbohydrate Intake The carbohydrate allowance is determined after protein and fat intake have been calculated and is individualized based on eating habits and glucose and lipid goals.
Emphasis is placed on whole grains, starches, fruits, and vegetables to provide the necessary vitamins, minerals, and fiber in the diet. The recommended daily consumption of fiber is the same for people with diabetes as for nondiabetics (20 g to 35 g). Although dietary fiber can improve serum lipid levels, the effect on glycemic control is minimal. Traditionally, complex carbohydrates were thought to produce lower blood glucose responses than simple sugars because sugars are digested and absorbed more rapidly. This belief, which influenced previous recommendations of replacing simple sugars in the diet with complex carbohydrates, has been disproved by clinical research.
For example, the glycemic response to fruits and milk has been found to be lower than the response to most starches, and sucrose has been found to produce a glycemic response similar to that of bread, rice, and potatoes. The rate of digestion of a given food seems to be more related to the presence of fat, degree of ripeness, cooking method, and preparation. Sucrose A modest amount of sugar is allowed in the daily diet of patients with type II diabetes. Sucrose and sucrose-containing foods may be substituted for other carbohydrates in the meal plan, but not simply added. Patients need to be taught how to make such substitutions using self-monitoring of capillary blood glucose (SMCBG) to evaluate the glycemic response.
The total nutrient content of the sucrose-containing food should be considered, particularly because sugar and fat are the main ingredients in many sweets. Obese individuals usually are advised to avoid sweets because of the potential of a small portion triggering overconsumption. Fructose A natural source of dietary fructose is fruits and vegetables. In addition, some sweeteners are derived from these sources. Moderate consumption is recommended, particularly concerning foods in which fructose is used as a sweetening agent. Although fructose has a lower glycemic effect than sucrose, it contains the same amount of calories and therefore should be limited in hypocaloric diets.
People with dyslipidemia also are advised to limit their consumption of fructose because of the potential adverse effects on serum triglyceride and LDL cholesterol levels. Other Nutritive/Nonnutritive Sweeteners and Fat Substitutes Nutritive sweeteners such as corn syrup, fruit juice/concentrate, honey, molasses, dextrose, and maltose do not seem to have a greater advantage or disadvantage over sucrose in terms of impact on calorie content or glycemic response, but they need to be accounted for in the meal plan.
Certain sugar alcohols (sorbitol, mannitol, xylitol) that commonly are used as sweeteners can produce a lower glycemic response than sucrose but seem to have no real advantage over sucrose or other nutritive sweeteners when consumed as part of mixed meals. Excessive consumption of sugar alcohols may cause laxative effects. Nonnutritive sweeteners (saccharin, aspartame, acesulfame K) have been approved by the Food and Drug Administration (FDA) for consumption by people with diabetes. These sweeteners are useful because they contribute no calories or carbohydrates to the diet when they are used as tabletop sweeteners or in soft drinks.
However, when sweeteners are used in foods that contain other nutrients and calories (ice cream, cookies, puddings), the foods must be worked into the meal plan. 1 Because many of the fat substitutes currently being used are derived from carbohydrate or protein sources, the content of these compounds is increased above the usual amounts in such products.
Patients need to be advised to review the carbohydrate and/or protein content when using products with fat substitutes. Vitamins and Minerals Supplementation generally is not recommended for people with diabetes when dietary intake is adequate and balanced. Patients who become chromium-deficient as a result of long-term parenteral nutrition may require chromium supplementation.
However, most people with diabetes are not chromium-deficient and do not benefit from supplementation. Similarly, magnesium does not need to be added to the diets of most patients with diabetes unless routine evaluation of serum magnesium reveals a deficiency. Patients taking diuretics may need potassium supplementation. However, hyperkalemia may require potassium restriction in patients with renal insufficiency, or hyporeninemic hypoaldosteronism, or in those taking angiotensin-converting enzyme (ACE) inhibitors. 6 One consideration may be the potential value of antioxidant supplements (vitamins E, C, and beta-carotene) in reducing atherosclerotic lesions and cataracts, both of which are common in type II diabetes. The value of such supplementation is yet to be confirmed.
The same recommendations used for the general population are appropriate for people with type II diabetes. Moderate consumption will not adversely affect blood glucose in patients whose diabetes is well controlled. Calories from alcohol should be included as part of the total calorie intake and reflected in the meal plan as a substitute for fat (one alcoholic beverage = two fat exchanges). For patients taking insulin, one or two alcoholic beverages per day are acceptable (one alcoholic beverage = 12 oz beer, 5 oz wine, or 1ring oz distilled spirits; sweet drinks should be avoided) taken with or in addition to the meal plan. However, some special considerations exist regarding alcohol intake.
Patients taking insulin or sulfonylureas are susceptible to hypoglycemia if alcohol is consumed on an empty stomach. Therefore, these individuals should make sure to take any desired alcohol with a meal. Patients with diabetes and coexisting medical problems such as pancreatitis, dyslipidemias, or neuropathy may need to reduce or abstain from alcohol intake.
- American Diabetes Association.
- Medical Management of Non-insulin-dependent (Type II) Diabetes, 3rd ed. Alexandria, Va: American Diabetes Association; 1994:22-39. American Diabetes Association. Diabetes 1996 Vital Statistics. Alexandria, Va: American Diabetes Association; 1996. Davidson MB.
- Diabetes Mellitus: Diagnosis and Treatment, 3rd ed. New York, NY: Churchill Livingstone; 1991:35-93. Henry RR. Protein content of the diabetic diet. Diabetes Care. 1994;17:1502-1513.
- Mudaliar SR, Henry RR. Role of glycemic control and protein restriction in clinical management of diabetic kidney disease. Endocr Pract. 1996;2:220-226. American Diabetes Association.
- Clinical practice recommendations 1995. Position statement: nutrition recommendations and principles for people with diabetes mellitus. Diabetes Care. 1995;18(suppl 1):16-19. Words/ Pages : 2,592 / 24