Nutritional Recommendations and Principles

Transcription

1 Position Statement Nutritional Recommendations and Principles for Individuals With Diabetes Mellitus: 1986 AMERICAN DIABETES ASSOCIATION In 1979 the Committee on Food and Nutrition of the American Diabetes Association published a special report entitled "Principles of Nutrition and Dietary Recommendations for Individuals With Diabetes Mellitus." Publication of the report was prompted by new and emerging information regarding effects of diet on blood glucose concentration in diabetic people and by information relating aberrations of blood lipid levels, particularly cholesterol, with atherosclerosis in the general population. Since 1979, much new information has been generated in the field of nutrition for management of diabetes. Questions have arisen as to the optimal carbohydrate, protein, and fat intake; the use of fiber; the role of the glycemic index and its relation to food exchanges; and the value of eicosapentanoic acid or fish oil. The 1980s also witnessed a transformation in the approach to nutrition education. Health care should be provided by a team of professionals, with each member of the team contributing a particular area of expertise. Ever-growing recognition of the needs of minority populations has dictated closer inspection of these requirements and a need to formulate new and more relevant approaches. This report updates the original principles and recommendations, based on information accumulated since 1979, and the evolving patterns of nutritional management. Nutritional recommendations for people with diabetes are similar to those of the American Heart Association, the National Cancer Institute (American Cancer Society), the Nutritional Committee for Recommendations for Children with Diabetes of the American Academy of Pediatrics, and the 1985 U.S. Dietary Guidelines. RECOMMENDATIONS Calories. Calories should be prescribed to achieve and maintain a desirable body weight. Carbohydrate intake. 1. The amount of carbohydrates should be liberalized, ideally up to 55-60% of the total calories, and individualized, with the amount dependent on the impact on blood glucose and lipid levels and individual eating patterns. 2. Whenever acceptable to the patient, foods containing unrefined carbohydrate/with fiber should be substituted for highly refined carbohydrates, which are low in fiber. 3. In some individuals, modest amounts of sucrose and other refined sugars may be acceptable, contingent on metabolic control and body weight. Protein intake. Americans in general consume too much protein. The recommended dietary allowance (RDA) for protein is 0.8 g/kg of body weight for adults. Elderly subjects may require more than the RDA. There are circumstances where the protein intake may be reduced, e.g., in patients with incipient renal disease. Total fat and cholesterol intake. Total fat and cholesterol intake should be restricted. Total fat should comprise <30% of total calories and cholesterol <300 mg/day. This level of intake may not be achievable within the context of the nutritional prescription and palatability. If total fat is reduced, all components should be proportionally reduced. Replacement of saturated fat with unsaturated fat may slow the progression of atherosclerosis. The addition of certain fats such as eicosapentanoic acid and monounsaturated fats may be acceptable; however, more research is needed to define their value. Alternative sweeteners. The use of various nutritive and nonnutritive sweeteners is acceptable in the management of diabetes. Salt intake. Many Americans eat more salt (NaCl) than is necessary. The recommended sodium intake is 1000 mg/ 1000 kcal not to exceed 3000 mg/day. In hypertensive subjects, salt may be harmful, and therefore intake should be reduced. Severe sodium restriction could also be harmful for certain individuals with poorly controlled diabetes, postural hypotension, and fluid imbalance. Alcohol. The same cautions regarding the use of alcohol that apply to the general public apply to people with diabetes. Specific problems may occur with hypoglycemia, neuropathy, glycemic control, obesity, and/or hyperlipidemia. 126 DIABETES CARE, VOL. 10 NO. 1, JANUARY-FEBRUARY 1987

2 Recommended daily intake (to be tailored to individual needs) Carbohydrate ^60 Protein (g/kg) 0.8* PUS 6-8 Fat (%)t S <10 MS 30-(PUS + S) Cholesterol (mg) <300 Fiber (g) 'The recommended dietary allowance for protein is 0.8 g/kg body wt for adults. Patients with incipient renal failure may require lower protein intakes. tlf total fat is reduced, all components, i.e., polyunsaturated (PUS), saturated (S), and monounsaturated (MS) fat, should be reduced proportionally. $25 g/1000 kcal for people taking low-calorie diets. Vitamins and minerals. Vitamins and minerals should meet the recommended requirements for health. There is no evidence unique to the patient with diabetes to warrant supplementation of vitamin and mineral intake unless the patient is on a very-low-calorie diet or other special circumstances exist. Calcium supplements may be necessary under special circumstances. GOALS FOR DIABETES MANAGEMENT 1. Restore normal blood glucose and optimal lipid levels. Maintain blood glucose as near to physiologic as possible to 1) prevent hyperglycemia and/or hypoglycemia, 2) prevent or delay the development of long-term cardiovascular, renal, retinal, neurologic complications associated with diabetes mellitus, 3) contribute to a normal outcome of pregnancies for women with diabetes. 2. Maintain normal growth rate in children and adolescents as well as the attaining and maintaining reasonable body weight in adolescents and adults. Any abnormal or unexplained deviation in growth rate or weight gain and/or loss as plotted on standard grids warrants an assessment of diabetes control, eating behavior, and caloric intake as well as consideration of alternative problems and/or diagnosis. 3. Provide adequate nutrition for the pregnant woman, the fetus, and lactation. 4- Stay consistent in the timing of meals and snacks to prevent inordinate swings in blood glucose levels for people using exogenous insulin. 5. Determine a meal plan appropriate for the individual's life-style and based on a diet history. Blood glucose monitoring results can then be used to integrate insulin therapy with the usual, as well as unanticipated, eating and exercise pattern. 6. Manage weight for obese people with non-insulin-dependent diabetes mellitus (NIDDM). Weight management involves specific changes in food intake and eating behaviors as well as increased activity level. Continued support and follow-up by qualified health professionals are important if long-term life-style changes are to be made. 7. Improve the overall health of people with diabetes through optimal nutrition. 40* METHODS TO ACHIEVE GOALS The ultimate goal and approach to nutrition education and counseling is to promote positive behavioral changes. For this to occur, a phased plan for nutrition counseling of people with diabetes that aims to achieve more than just education is important. The key components are listed. Initial or "survival" phase. In the first stage, a simplified, individualized meal plan and an introduction to the basics of meal planning are needed. In-depth and continuing phase. During this phase, the person basically learns how to make decisions. Continuing education and counseling are needed by everyone with diabetes. All adults should be seen by a nutritionist every 6 mo to 1 yr so that subtle changes in life-style can be noted and appropriate nutritional changes made. Some people, especially those who need to control their weight, may require more frequent evaluation and counseling. Children and adolescents with diabetes should be seen by a nutritionist at least every 6 mo, preferably every 3 mo. Nutrition is a changing field, and continuing evaluation and education are essential for people with diabetes to incorporate these changes in their management programs. Team approach. Whenever possible, a team approach to education and counseling should be used that includes the person with diabetes as an integral member. Family members and "significant others" also need to be an integral part of the education program. A meal-plan prescription and its implementation should be planned by the physician and dietitian in conjunction with other members of the healthcare team. A registered dietitian with expertise in diabetes management is the ideal member of the multidisciplinary team to provide this education and counseling. Individualization. It is essential that the meal plan, education, and counseling program be individualized for the person with diabetes. With the basic goals of meal planning in mind, the individual's plan needs to be realistic and provide as much flexibility as possible, allowing integration of therapeutic measures into his/her life-style. Educational tools that are appropriate for the individual should be selected, taking into account age and educational level as well as the level of existing nutritional knowledge. Exercise. Regular activity should be encouraged and incorporated into the daily schedule; aerobic exercise is recommended. Individuals >30 yr old or who have had diabetes for 5=10 yr should have physician approval to begin an exercise program. For people with insulin-dependent diabetes mellitus (IDDM), the major benefits of exercise are cardiovascular conditioning, weight maintenance, and lowering of lipid levels. For people with NIDDM, conditioning may also be a benefit, but even light exercise can be important in a management program to control blood glucose and lipid levels. PRINCIPLES OF GOOD NUTRITION IN DIABETES Carbohydrates, fiber, and glycemic index. Current evidence suggests that high-fiber diets, especially of the soluble variety, DIABETES CARE, VOL. 10 NO. 1, JANUARY-FEBRUARY

3 and soluble-fiber supplements offer some improvement in carbohydrate metabolism, lower total cholesterol and lowdensity lipoprotein (LDL) cholesterol, and have other beneficial effects. The insoluble fibers, e.g., wheat bran, may not have these beneficial effects. Current estimates of the dietary fiber intake of adults in the United States range from ~10 to 30 g/day, with men averaging 19 g/day and women 13 g/day. A practical goal would be to establish the level of intake and to gradually increase it with the goal of doubling the intake for most individuals. An intake of up to 40 g of fiber/day or 25 g/1000 kcal of food intake appears to be beneficial; in many individuals on weight-reducing diets, higher levels may be unacceptable because of gastrointestinal side effects. However, the level of maximum benefit has not been determined, but a maximum intake of 50 g seems reasonable. Fiber supplementation appears to be beneficial only if given with a diet comprising at least 50% of the calories as carbohydrate. Foods should be selected with moderate to high amounts of dietary fiber from a wide variety of foods. These foods include legumes, lentils, roots, tubers, green leafy vegetables, all types of whole-grain cereals (e.g., wheat, barley, oats, corn, and rye), and fruits. Fruits and vegetables should be eaten raw to maximize the fiber effect, and not pureed, which causes loss or reduction of the fiber effect. The 1986/ 1987 exchange lists compliled by the American Diabetes Association in conjunction with the American Dietetic Association will highlight foods with a high fiber content. Children may also benefit from an increase in the fiber content of their diets, but younger children may not tolerate large amounts of fiber. Pregnant diabetic women appear to tolerate fiber well, but there are too few studies to advise for or against its use in pregnancy. Insufficient data are available on the long-term safety of high-fiber supplements. It is possible that people at risk for deficiencies, e.g., postmenopausal women, the elderly, or growing children, may require supplements of calcium and trace minerals. People with upper gastrointestinal dysfunction risk bezoar formation and are cautioned against a diet high in fiber of the leafy vegetable type. Careful attention must be paid to insulin dose, because hypoglycemia can result if there is a radical change in fiber intake and insulin dose is not reduced appropriately. Care must be exercised in the use of "novel" fibers, e.g., the wood celluloses, because little is known of their safety and efficacy. Abdominal cramping, discomfort, loose stools, and flatulence can be minimized by starting with small servings and increasing the portions gradually. Factors other than fiber may result in a food producing relatively flat blood glucose profiles. These foods may favorably influence blood lipids. Classification of foods by their glycemic effects may facilitate application of this information in day-to-day management. Currently the consistencies in estimations of the glycemic indices suggest that glycemic indexing of foods may be used, in simplified form, as part of the exchange system. There are inconsistencies, however, that suggest this is not the time for general application. A considerable amount of multifaceted research is required to evaluate the relative value of the glycemic index of foods versus the exchange system. In the meantime, however, glycemic index tables provide a means of identifying the starchy foods with lower glycemic potential that may be offered on trial to people with diabetes. The text of the exchange-list booklet has been rewritten to make it more useful in the education of people with diabetes and will reflect current nutritional trends in management for people with diabetes. Hyperlipidemia. Almost all of the risk factors for atherosclerosis and coronary heart disease identified in population studies are overrepresented in diabetes. Of these risk factors, plasma lipids and lipoproteins are the targets for altered dietary habits. Such alteration must be qualified with an understanding of the relationship between diabetes mellitus and lipoprotein metabolism and evidence of a favorable outcome of a fat-modified diet on this relationship. The following conclusions can be drawn from the literature. I) In untreated diabetes mellitus, the serum concentration of LDL cholesterol is within normal limits. Hyperlipidemia, if present, involves an increase in serum triglyceride, very-low-density lipoprotein (VLDL) triglyceride, and VLDL cholesterol concentrations. High-density lipoprotein (HDL) cholesterol levels may also be decreased, particularly in NIDDM. 2) Diabetes mellitus and familial hyperlipoproteinemias are not genetically coinherited. Their frequent coexistence could result from their independent association with other metabolic disorders such as obesity. 3) The mechanism of the lipoprotein disorder in diabetes affects the metabolism of plasma VLDL, LDL, and HDL. The disorder greatly relates to the metabolic milieu of the diabetic syndrome, although the mechanism(s) of increased apolipoprotein B production and decreased HDL cholesterol concentration observed in some diabetic individuals remains unknown. 4) Treatment of hyperglycemia is associated with improvement in plasma VLDL and LDL concentrations and can be accompanied by improvement in plasma HDL levels, particularly when associated conditions such as obesity are simultaneously treated. 5) Epidemiological surveys, dietary intervention trials, and studies in experimental animals provide strong evidence that fat and cholesterol restriction could exert favorable influences on plasma lipid and lipoprotein levels as well as on cardiovascular risk. Based on these conclusions, the following recommendations are made. I) Because of the high risk of cardiovascular disease (CVD) among subjects with diabetes, and the known association between abnormalities in plasma lipids and lipoprotein concentrations and increased CVD risk, and because of the established favorable effects of a fat-modified diet on plasma lipids and lipoprotein concentrations, as a minimal requirement, subjects with diabetes should be prescribed a fat-modified diet in which total fat is restricted to <30% of the total calories: saturated fat <10%, polyunsaturated fat <10% (preferably 6-8%), and the rest as monounsaturated fat. The cholesterol content should not be >300 mg/day. These recommendations are comparable with those of the American Heart Association (AHA) Phase I, recom- 128 DIABETES CARE, VOL. 10 NO. 1, JANUARY-FEBRUARY 1987

4 mended for the American public at large. Liberalization of the carbohydrate intake, of the unrefined variety, may also be beneficial in the management of hyperlipidemia. 2) Because normolipemia may not be achieved with optimal antidiabetic therapy in some subjects, presumably due to coexistence of diabetes and a disorder of lipoprotein metabolism, a stricter fat-modified diet (comparable with that of the AHA Phase II: fat 25% of calories; cholesterol mg/day; or Phase III: fat 20% of calories, cholesterol mg/ day) should be prescribed for individuals who continue to exhibit persistently elevated LDL cholesterol. Note that under these circumstances, protein intake will have to be liberalized. These diet plans should be carefully constructed by a nutritionist. Additional hypolipidemic agents may also be necessary. Individuals who continue to exhibit an increase in VLDL triglyceride and cholesterol concentrations are not likely to benefit from the stricter fat-modified diets of AHA Phases II and III. Because these are probably due to lipoproteinemic disorders, e.g., familial combined hyperlipidemia, their management, in addition to the AHA Phase I diet, includes hypolipidemic agents appropriate for the treatment of these disorders. 3) In the unusual circumstance of massive hypertriglyceridemia (plasma triglycerides mg/dl) in which the danger of acute pancreatitis is high, the dietary fat intake should be restricted initially to 10-20% of total calories together with appropriate antidiabetic therapy, management of accompanying causes of secondary hyperlipidemia, and possibly a fibric acid derivative. These recommendations should be further modified to accommodate the nutritional management of accompanying disorders, e.g., obesity, hypertension, and renal disease. In addition, appropriate medical management of other risk factors for coronary heart disease, e.g., cigarette smoking and hypertension, should be emphasized. Protein intake. The average American eats more protein than is necessary to maintain normal health. Traditionally, diabetic dietary recommendations have emphasized protein. However, there is growing evidence that protein intake should be reduced in individuals who are identified at risk for or who have clinical evidence of nephropathy. The Recommended Dietary Allowance (RDA) for protein is 0.8 g/kg body wt for adults. Many of the foods that are being encouraged for their fiber content, e.g., legumes, are also high in protein, and care must be exercised in their prescription. An acute catabolic state will increase the need for protein that must be met. During gestation, lactation, and periods of rapid growth, there is a modest increased need for protein. Elderly subjects may have greater protein requirements than the RDA. Exercise and energy requirements. The energy content of the diet should be adjusted to meet the energy requirements of the individual patient. Because most people with IDDM are thin when first diagnosed, a diet adequate for normal growth and development in children and adolescents and adults should be a major goal. Attention should be given to meet the energy needs of the individual's habitual level of physical activity and to compensate for the increased nutritional requirements of special situations, e.g., pregnancy, lactation, or other hypermetabolic conditions. When obesity is present, as is common with NIDDM, the energy content of the diet should be 2=500 kcal/day below energy requirements to promote weight loss and attainment of a reasonable body weight. Sodium. Individuals with diabetes, as well as the general public, are cautioned to avoid using too much sodium. Sodium is essential to the human body, but most Americans consume much more than necessary, especially from processed foods. Table salt, which is 40% sodium, is added to many foods in processing. A daily intake of 1000 mg of sodium per 1000 kcal not to exceed 3000 mg is recommended by the AHA. The principal concern with high sodium consumption is directed toward people with hypertension and those susceptible to the development of hypertension. Not everyone is sodium sensitive, but because people with diabetes are frequently hypertensive, it seems prudent, especially in relationship to complications, to make modest restrictions on sodium intake. In patients with diabetes that is severely out of control or who have problems with fluid balance or postural hypotension, salt may be beneficial, and medical recommendations for its use should be made. Alternative sweeteners. 1. The use of alternative sweeteners of both the noncaloric (e.g., aspartame and saccharin) and the caloric varieties (e.g., fructose and sorbitol) is acceptable in the management of diabetes. However, the use of caloric sweeteners (e.g., fructose and sorbitol) in the belief that their energy contribution is not significant may undermine efforts to lose weight and could lead to weight gain. They cannot be substituted into the meal plan for noncaloric sweeteners, because their caloric contribution may be substantial and must be accounted for in the meal plan. Individuals in whom diabetes is reasonably well controlled may use fructose or sorbitol without adverse short-term effects on blood glucose. The metabolic effects of chronic ingestion of diets containing fructose and/or sorbitol need further study to establish whether their use as part of diabetes management is beneficial. There is no evidence, however, that ingested sorbitol can gain access to the internal cellular milieu and contribute to the complications of diabetes. 2. If sweeteners are used, the use of various sweeteners, each with its particular advantages, is recommended to distribute any potential risks. 3. Excessive intake of any sweetener requires nutritional counseling. Individual ingestion of sweetener should be limited to the established safe levels when such figures are available. The limitation of any sweetener, however, should be individualized and take into consideration other sweetener use and overall diet and nutritional adequacy. 4. Better labeling is needed to inform consumers about the sweeteners contained in food. Food labels should list the specific individual sweeteners and their amounts (in mg or g) per serving. 5. Continued research is needed to identify the risks as well as metabolic effects of long-term use of individual sweet- DIABETES CARE, VOL. 10 NO. 1, JANUARY-FEBRUARY

5 eners and combinations of sweeteners in humans, particularly in individuals with diabetes. Because their intake as a group may be greater than that of the general population, specific studies on children, adolescents, and adults are needed. More information is needed about the diabetic palate and the preference for sweetness in children and adults to determine actual needs for alternative sweeteners. Alcohol. The same precautions regarding the use of alcohol that apply to the general public apply to people with diabetes. There are, however, additional considerations for glycemic control, prevention of hypoglycemia, hyperlipidemia, and weight control. If used, alcohol should be taken in moderation, i.e., not more than 2 equivalents of an alcoholic beverage once or twice a week. One equivalent or 1 oz of liquor is equal to the amount of alcohol in a 1.5-oz shot of distilled beverage, a 4-oz glass of wine, or 12 oz of beer. Light beer and dry wine may be better choices because of the lesser carbohydrate content than regular beer or wine. Alcoholic beverages should be consumed with food. For IDDM individuals, 2 oz of an alcoholic beverage may be taken in addition to the regular meal plan. No food should be omitted, because alcohol-induced hypoglycemia may occur and because alcohol does not require insulin for its metabolism. For NIDDM individuals, alcohol is best substituted for fat exchanges because it is high in kilocalories and because it is metabolized like fat (1 oz = 2 fat exchanges). These recommendations should not be used to encourage alcohol use in people with diabetes who risk alcohol abuse. SPECIAL CONSIDERATIONS FOR IDDM The meal plan is important for avoiding hyperglycemia, preventing hypoglycemia, and maintaining metabolic balance. Whether it plays a specific role in preventing or delaying the neuropathic, microvascular, or macrovascular complications associated with IDDM is still under review. Consistency of food intake is very important in the treatment of IDDM. The following must be considered when preparing a meal plan for infants, children, adolescents, and adults with IDDM: I) timing of meals and snacks; 2) composition of food; 3) energy content; 4) level of physical activity; 5) age, sex, and pubertal status of patient; 6) growth assessment; and 7) pregnancy and lactation needs. Timing and consistency of food. The time at which meals are taken, how much time elapses between insulin injection and food intake, and the number of meals and snacks eaten each day should be dictated by individual needs. The needs can be determined by capillary blood glucose monitoring and attention to life-style, physical activity, insulin effect, and administration. Day-to-day consistency is crucial to counterbalance other aspects of IDDM treatment. Timing of snacks may change with the use of pure pork or human insulin and their different peak effects and duration of action. Meal plan composition. For most patients with IDDM, nutritional recommendations are those in the general outline. Energy content. Height and weight data must be plotted routinely until growth is completed and to help prevent obesity. Nutritional prescriptions should be adjusted to meet the needs for normal growth. Special situations. Although all meal plans should be individualized, certain circumstances require attention in patients with IDDM: 1) the youngster who is a picky eater (i.e., no vegetables); 2) people with eating disorders (i.e., obesity, bulimia, anorexia nervosa); 3) people with gastrointestinal disease (i.e., Crohn's colitis, celiac disease, giardiasis, immunoglobulin A deficiency); 4) people with low iron stores (i.e., positive gastroparietal antibodies with achlorhydria), which may require vitamin or mineral supplementation; and 5) people, especially pregnant women and very young children with IDDM, who use nutritive and nonnutritive sweeteners. In IDDM people, total daily energy intake should be distributed consistently throughout the day with at least three regular meals, a bedtime snack, and one or more betweenmeal snacks. If the patient is taking two or more injections of short-acting insulin daily or is using short-acting insulin as a supplement to the longer-acting insulins, greater flexibility in meals may be allowed by adjustment of insulin dosage. This decision, however, should be made after discussion with the physician and nutritionist and should be based on the results of glucose monitoring. Dietary adjustments for exercise. Because physical activity may vary considerably from day to day, adjustments in energy intake and insulin dosage may be required to avoid hypoglycemia in insulin-treated patients. Metabolic fuel utilization during exercise depends on many factors, e.g., the intensity and duration of exercise, the level of physical training, the antecedent diet, and the metabolic state of the individual. In IDDM individuals, vigorous exercise should be undertaken only if blood glucose is in the range of mg/dl and there is no ketosis. If the preexercise blood glucose concentration is too low, exercise may result in hypoglycemia; if it is too high and there is insulin deficiency, exercise may cause a further increase in blood glucose and ketosis. Several strategies may be used to avoid hypoglycemia during or after vigorous, prolonged, or nonhabitual exercise in IDDM patients. Supplemental carbohydrate-containing snacks may be taken before and during exercise to maintain blood glucose within the normal range, and increased energy intake, primarily as carbohydrate, may be needed for up to 24 h after exercise to provide for repletion of muscle as well as liver glycogen stores and to prevent postexercise hypoglycemia. The amount and frequency of supplemental feedings may be estimated from predicted rates of glucose oxidation during exercise or empirically from self-monitoring of blood glucose. In addition, adjustments in insulin dosage and timing may be needed to prevent exercise-induced hypoglycemia. This should always be done after consultation with the physician and the health-care team. Individuals taking a single dose of intermediate-acting insulin may, after consultation with the physician, decrease the usual dose by 30-35% before vigorous or prolonged exercise and may take a second dose later in 130 DIABETES CARE, VOL. 10 NO. 1, JANUARY-FEBRUARY 1987

6 the day if necessary. Those on combined intermediate- and short-acting insulin schedules may need to reduce or omit the short-acting insulin and decrease the intermediate-acting insulin before exercise. If a multiple-dose regimen with primarily short-acting insulin or an insulin-infusion device is used, the dosage before exercise may need to be reduced by ^50% and supplemental insulin taken after exercise, depending on the results of glucose self-monitoring. In general, it is best to avoid exercise within 1 h after an insulin injection to prevent rapid absorption and hyperinsulinemia during exercise. When this is not possible, the preexercise dose of insulin should be injected in a nonexercising area to minimize the exercise-enhanced absorption. Because individual patterns of exercise are extremely variable, the most effective combination of supplemental feeding and adjustment of insulin dosage may depend on frequent glucose self-monitoring and previous experience. Intensified insulin therapy. This poses two potential problems. If successful, hypoglycemic events may occur more frequently. Such intensified therapies (multidose insulin and/ or continuous subcutaneous insulin infusion are also associated with weight gain reflected in more positive energy balance. SPECIAL CONSIDERATIONS FOR N1DDM There are special needs for obese patients. Dietary interventions directed toward weight reduction and improvement in blood glucose and lipids of the obese person with NIDDM have the greatest potential for a significant positive effect on morbidity and mortality. Individuals who are both obese and have diabetes are at far greater risk than those who are only obese. The metabolic improvements achieved with weight reduction of obese diabetic patients are indisputable and include reduction in hyperglycemia, hyperlipidemia, hypertension, and proteinuria. Weight reduction also leads to more general benefits, including improved pulmonary function, reduced risks at operation, and reduction of musculoskeletal problems. In addition, the improvement in glucose tolerance with reduction of caloric intake may reduce or eliminate the need for oral hypoglycemic agents or insulin. The timing of weight loss relative to the progression of diabetes may be of critical importance to the long-term prognosis and, possibly, to the delay of onset or prevention of the development of complications. Attention should be given to individuals with upper-body fat localization because this form of obesity, even when mild, is associated with higher glucose levels, exacerbated insulin resistance, greater abnormality of the lipoprotein profile, and increased cardiovascular risk. Although much is still unknown about the relative merits of various weight-reduction regimens, and the optimal methods for producing sustained weight loss have to be identified, several features should be considered in making a choice among the available approaches. 1. The diet should be nutritionally balanced and the calorie level restricted. A weight-reducing diet should be nutritionally complete, providing for various foods. Moderate caloric restriction of kcal below usual daily food intake levels may be optimal in producing gradual sustained weight loss. Under professional supervision, very-low-calorie diets ( kcal/day) can be effective and safe for severely obese NIDDM individuals, particularly where there is a need for rapid and significant weight reduction. Vitamin and mineral supplementation should be used to meet the RDA. 2. A maintenance program should be provided. After successful weight loss, there is often great difficulty in sustaining the reduced body weight. It appears that stabilization of body weight at a reduced level requires the continued ingestion of a restricted calorie level and a lifelong commitment to sustaining the reduced weight. The prevention of recidivism with regaining of lost weight requires greater attention if the benefits of reducing body weight of the obese are to be realized. Although normalization of body weight is a desirable goal, even modest caloric restriction per se may be beneficial due to the positive effects on blood glucose and requirements for insulin and oral antidiabetic agents. 3. Energy requirements for exercise in NIDDM individuals are not significantly different from those of nondiabetic people. Supplemental food before and during exercise is not needed to prevent hypoglycemia and is not recommended, except under conditions of severe, prolonged exercise such as endurance sports. In patients taking sulfonylureas there is a slight increased risk of hypoglycemia during exercise, and supplemental intake may be required in some cases. This may be determined by glucose self-monitoring. NIDDM individuals taking insulin should usually decrease their insulin dosage before exercise and may take supplemental food if needed to prevent hypoglycemia during or after exercise. Physical exercise may be used as an adjunct to low-calorie diets for weight reduction in obese NIDDM patients. Exercise alone, without concurrent caloric restrictions, rarely results in significant weight loss. When the energy content of the diet is severely restricted (<1000 kcal/day), carbohydrate intake should be maintained to preserve normal muscle glycogen stores and the capacity for vigorous exercise and endurance. SPECIAL NEEDS OF MINORITY PATIENTS Diet therapy for minority patients must be directed to the most common form of diabetes, NIDDM, and tailored to the culture of the population. Educators must utilize techniques and written materials appropriate for the patient and the family. Nutrition information can be divided into sequential, manageable steps, which can then be individualized into the patient's setting. Appropriate traditional, ethnic, and cultural foods can be encouraged. No simple set of exchange lists will suffice for all minority groups. Because food grouping may be abstract, exchange lists may be inappropriate for all situations. Simple, single-concept messages should be developed that can be adapted to the foods of specific groups. DIABETES CARE, VOL. 10 NO. 1, JANUARY-FEBRUARY

7 SUMMARY The management of diabetes requires a careful balance between nutrient intake, energy expenditure, and the dose and timing of oral hypoglycemic agents and/or insulin. Meal planning should commence with an initial teaching of survival skills and a goal-oriented progression through phases of increasing information acquisition, incorporation of information into new knowledge and skills, a program of continuing education, and reinforcement with an ultimate change in the behavior pattern. These tasks are best accomplished by a multidisciplinary team approach that uses various skills in nutrition planning and health care. The use of preprinted, handout diet plans is strongly discouraged. The need for essential basic nutrients is the same for all people of equivalent age, sex, and size, diabetic or not. The nutrient needs of diabetic people can usually be met without the use of special dietetic or diabetic foods. Calories should be prescribed according to energy needs to achieve and maintain a desirable body weight. The amount of carbohydrate should be liberalized. Whenever possible and acceptable to the patient, natural foods containing unrefined carbohydrate should be substituted for the highly refined carbohydrates that are low in fiber. The use of supplemental fiber is acceptable within the limits defined above. In some individuals, modest amounts of refined carbohydrates are acceptable, depending on weight control and impact on blood glucose and serum lipid concentrations. The high risk of macrovascular disease in patients with diabetes and associated hyperlipidemia dictates a need to restrict total fat intake and cholesterol and replace saturated fats with unsaturated fats to slow the progression of atherosclerotic disease. The use of supplemental eicosapentanoic acids may be acceptable, but more research into the benefits is needed. Foods with low glycemic indices may be tried for their overall effect in the diets of given individuals. Recommendations made for meal planning should be based on an updated version of the food exchanges. At a later stage these lists may be formally supplemented with information on low glycemic index selections. No food exchange list is applicable to all groups of people. However, in minority groups, specialized and simplified initial single-concept approaches are recommended. Food selection in these groups must take into consideration socioeconomic, cultural, and ethnic factors. Americans eat far more protein and salt than is required for optimum nutrition. Protein intake should be restricted to the RDA except in groups at risk of negative nitrogen balance. In the future, tests may be devised to predict which individuals are at risk of nephropathy and would benefit from severe protein restriction. Limited salt intake is also advised. Particular nutritive and nonnutritive sweeteners are not encouraged but are acceptable. Use of various nonnutritive sweeteners is encouraged to offset the possible disadvantages that may result from excessive consumption of a single agent. People with diabetes are under the same restrictions in regard to the use of alcohol as the general population, with particular attention to alcoholic hypoglycemia. These recommendations are based on current knowledge. Nutrition science is a rapidly growing and dynamic field in which what is sound practice today may not be so tomorrow. These recommendations are, however, similar to those advocated by diabetes associations throughout the world and by the American Heart and Cancer Associations and the Amercian Academy of Pediatrics. Nonetheless, there are many unanswered questions, and answers will only be possible with support for diligent research into these areas. By continued endeavors and timely revisions of these guidelines, Americans should benefit greatly from new knowledge in the area of nutrition. The recommendations and principles were approved by the Board of Directors, 18 October 1986, and developed by a task force of the American Diabetes Association: Aaron I. Vinik, MD, Chairman Phyllis A. Crapo, RD, Vice-Chairman Stuart J. Brink, MD Marion J. Franz, RD, MS Dorothy M. Gohdes, MD Barbara C. Hansen, PhD Edward S. Horton, MD David Jenkins, MD Ahmed Kissebah, MD Andrea Lasichak, RD Judith Wylie-Rosett, EDD, RD 132 DIABETES CARE, VOL. 10 NO. 1, JANUARY-FEBRUARY 1987