* People with diabetes should receive individualized MNT as needed to achieve treatment goals, preferably provided by a registered dietitian familiar with the components of diabetes MNT. (B)
* Both the amount (grams) of carbohydrate as well as the type of carbohydrate in a food influence blood glucose level. Monitoring total grams of carbohydrate, whether by use of exchanges or carbohydrate counting, remains a key strategy in achieving glycemic control. (A)
* The use of the glycemic index/glycemic load may provide an additional benefit over that observed when total carbohydrate is considered alone. (B)
* Low-carbohydrate diets (restricting total carbohydrate to <130 g/day) are not recommended in the management of diabetes. (E)
* To reduce the risk of nephropathy, protein intake should be limited to the recommended dietary allowance (RDA) (0.8 g/kg) in those with any degree of CKD. (B)
* Saturated fat intake should be <7% of total calories. (A)
* Intake of trans fat should be minimized. (E)
* Weight loss is recommended for all overweight (BMI 25.0’29.9 kg/m2) or obese (BMI 30.0 kg/m2) adults who have, or are at risk for developing, type 2 diabetes. (E)
* The primary approach for achieving weight loss is therapeutic lifestyle change, which includes a reduction in energy intake and an increase in physical activity. A moderate decrease in caloric balance (500’1,000 kcal/day) will result in a slow but progressive weight loss (1’2 lb/week). For most patients, weight loss diets should supply at least 1,000’1,200 kcal/day for women and 1,200’1,600 kcal/day for men. (E)
* Initial physical activity recommendations should be modest and based on the patient’s willingness and ability, gradually increasing the duration and frequency to 30’45 min of moderate aerobic activity, 3’5 days/week (goal at least 150 min/week). Greater activity levels of at least 1 h/day of moderate (walking) or 30 min/day of vigorous (jogging) activity may be needed to achieve successful long-term weight loss. (E)
* Drug therapy for obesity and surgery to induce weight loss may be appropriate in selected patients. (E)
* Nonnutritive sweeteners are safe when consumed within the acceptable daily intake levels established by the Food and Drug Administration (FDA). (A)
* If adults with diabetes choose to use alcohol, daily intake should be limited to a moderate amount (one drink per day or less for adult women and two drinks per day or less for adult men); one drink is defined as 12 oz beer, 5 oz wine, or 1.5 oz distilled spirits. (A)
* Routine supplementation with antioxidants, such as vitamins E and C and ??-carotene, is not advised because of lack of evidence of efficacy and concern related to long-term safety. (A)
* Benefit from chromium supplementation in people with diabetes or obesity has not been conclusively demonstrated and, therefore, cannot be recommended. (E)
MNT is an integral component of diabetes prevention, management, and self-management education. In addition to its role in preventing and controlling diabetes, the ADA recognizes the importance of nutrition as an essential component of an overall healthy lifestyle. These guidelines are based on principles of good nutrition for the overall population from the 2005 Dietary Guidelines and the RDAs from the Institute of Medicine of the National Academies of Sciences. A review of the evidence and detailed information can be found in the 2002 ADA technical review on this topic and the 2004 ADA Statements regarding dietary carbohydrate and weight management.
Goal of MNT that applies to individuals with pre-diabetes:
* Decrease the risk of diabetes and CVD by promoting physical activity and healthy food choices that result in moderate weight loss that is maintained or, at a minimum, prevents weight gain.
Goal of MNT that applies to all individuals with diabetes:
* Prevent and treat the chronic complications of diabetes by attaining and maintaining optimal metabolic outcomes, including blood glucose and A1C level, LDL and HDL cholesterol and triglyceride levels, blood pressure, and body weight (Table 6).
Achieving nutrition-related goals requires a coordinated team effort that includes the active involvement of the person with pre-diabetes or diabetes. Because of the complexity of nutrition issues, it is recommended that a registered dietitian who is knowledgeable and skilled in implementing nutrition therapy into diabetes management and education be the team member who provides MNT. However, it is essential that all team members are knowledgeable about nutrition therapy and are supportive of the person with diabetes who needs to make lifestyle changes.
MNT involves a nutrition assessment to evaluate the patient’s food intake, metabolic status, lifestyle, readiness to make changes, goal setting, dietary instruction, and evaluation. To facilitate adherence, the plan should be individualized and take into account individual cultural, lifestyle, and financial considerations. Monitoring of glucose and A1C, lipids, blood pressure, and renal status is essential to evaluate nutrition-related outcomes. If goals are not met (Table 6), changes must be made in the overall diabetes care and management plan.
Overweight and obesity are strongly linked to the development of type 2 diabetes and can complicate its management. Obesity is also an independent risk factor for hypertension and dyslipidemia as well as CVD, which is the major cause of death in those with diabetes. Moderate weight loss improves glycemic control, reduces CVD risk, and can prevent the development of type 2 diabetes in those with pre-diabetes. Therefore, weight loss is an important therapeutic strategy in all overweight or obese individuals who have type 2 diabetes or are at risk for developing diabetes. The primary approach for achieving weight loss, in the vast majority of cases, is therapeutic lifestyle change, which includes a reduction in energy intake and an increase in physical activity. A moderate decrease in caloric balance (500’1,000 kcal/day) will result in a slow but progressive weight loss (1’2 lb/week). For most patients, weight loss diets should supply at least 1,000’1,200 kcal/day for women and 1,200’1,600 kcal/day for men.
In selected patients, drug therapy to achieve weight loss as an adjunct to lifestyle change may be appropriate. However, it is important to note that regain of weight commonly occurs on discontinuation of medication. In patients with severe/morbid obesity, surgical options, such as gastric bypass and gastroplasty, may be appropriate and allow significant improvement in glycemic control with reduction or discontinuation of medications. It is important to fully evaluate the patient for existing or risk for CVD and improve glycemic control preoperatively in order to decrease the risk of complications. It is important to counsel patients on the risks of surgery, including mortality, depression, hypoglycemia, nutritional deficiencies, osteoporosis, and weight regain over the long term. Very little data are currently available on the long-term consequences of surgery for weight loss in people with diabetes. The potential benefits should be weighed against short- and long-term risks.
Physical activity is an important component of a comprehensive weight-management program. Regular moderate-intensity physical activity enhances long-term weight maintenance. Regular activity also improves insulin sensitivity, glycemic control, and selected risk factors for CVD (i.e., hypertension and dyslipidemia), and increased aerobic fitness decreases the risk of coronary heart disease (CHD). Initial physical activity recommendations should be modest, based on the patient’s willingness and ability, gradually increasing the duration and frequency to 30’45 min of moderate aerobic activity, 3’5 days/week, when possible. Greater activity levels of at least 1 h/day of moderate (walking) or 30 min/day of vigorous (jogging) activity may be needed to achieve successful long-term weight loss.
Regulation of blood glucose to achieve near-normal levels is a primary goal in the management of diabetes, and thus, dietary techniques that limit hyperglycemia following a meal are important in limiting the complications of diabetes. Both the amount (grams) and type of carbohydrate in a food influence blood glucose level. The total amount of carbohydrate consumed is a strong predictor of glycemic response, and thus, monitoring total grams of carbohydrate, whether by use of exchanges or carbohydrate counting, remains a key strategy in achieving glycemic control. A recent analysis of the randomized controlled trials that have examined the efficacy of the glycemic index (a measure of the effect of type of carbohydrate) on overall blood glucose control indicates that the use of this technique may provide an additional benefit over that observed when total carbohydrate is considered alone.
Low-carbohydrate diets are not recommended in the management of diabetes. Although dietary carbohydrate is the major contributor to postprandial glucose concentration, it is an important source of energy, water-soluble vitamins and minerals, and fiber. Thus, in agreement with the National Academy of Sciences’Food and Nutrition Board, a recommended range of carbohydrate intake is 45’65% of total calories. In addition, because the brain and central nervous system have an absolute requirement for glucose as an energy source, restricting total carbohydrate to <130 g/day is not recommended.
In the U.S., mean protein intake from foods (not including supplements) accounts for 15’20% of average energy intake, is fairly consistent across all ages from childhood to old age, and appears to be similar in individuals with diabetes. The dietary reference intake (DRI)-acceptable macronutrient distribution range for protein is 10’35% of energy intake and the RDA is 0.8 g high-quality protein ?� kg body wt’1 ?� day’1.
Dietary intake of protein is similar to that of the general public in individuals with diabetes and usually does not exceed 20% of energy intake. Intake of protein in this range may be a risk factor for the development of diabetic nephropathy. Based on studies in patients with varying stages of nephropathy, it seems prudent to limit protein intake in those with diabetes to the RDA (0.8 g/kg), which would be 10% of total calories.
Saturated and trans fatty acids are the principal dietary determinant of plasma LDL cholesterol, the major risk factor for CVD. In nondiabetic individuals, reducing saturated and trans fatty acids and cholesterol intake decreases plasma total and LDL cholesterol but may also reduce HDL cholesterol. Importantly, the ratio of LDL to HDL cholesterol is not adversely affected. Studies in individuals with diabetes demonstrating the effects of specific percentages of dietary saturated and trans fatty acids and specific amounts of dietary cholesterol on CVD risk are not available. However, those with diabetes are considered to be at similar risk to those with a past history of CVD. Therefore, because of a lack of specific information, the goal for dietary fat intake (amount and type) for individuals with diabetes is the same as for those without diabetes with a history of CVD. The most recent guidelines from the National Cholesterol Education Program recommend that total fat be 25’35% of total calories and saturated fat <7%. Guidelines from the American Heart Association also recommend that saturated fat be <7% in those with diabetes, given their increased risk of CVD. Intake of trans fat should be minimized.
Optimal macronutrient mix
For those individuals seeking guidance regarding macronutrient distribution, the DRIs may be helpful The DRI report recommends that to meet the body’s daily nutritional needs while minimizing risk for chronic diseases, adults (in general, not specifically those with diabetes) should consume 45’65% of total energy from carbohydrate, 20’35% from fat, and 10’35% from protein. Although numerous studies have attempted to identify the optimal combination of macronutrients for those with diabetes, it is unlikely that any one such combination of macronutrients exists. The best mix of carbohydrate, protein, and fat appears to vary depending on individual circumstances.
Similar to the general population, people with diabetes are encouraged to choose a variety of fiber-containing foods, such as legumes, fiber-rich cereals ( 5 g fiber/serving), as well as fruits, vegetables, and whole-grain products because they provide vitamins, minerals, fiber, and other substances important for good health.
Reduced calorie sweeteners
Reduced calorie sweeteners approved by the FDA include sugar alcohols (erythritol, hydrogenated starch hydrolysates, isomalt, lactitol, maltitol, mannitol, sorbitol, and xylitol) and tagatose. Studies using subjects with and without diabetes have shown that sugar alcohols produce a lower postprandial glucose response than sucrose or glucose and have lower available energy. Sugar alcohols contain, on average, 2 calories/gram (one-half the calories of other sweeteners such as sucrose). With foods containing sugar alcohols, subtraction of one-half of sugar alcohol grams from total carbohydrate grams is appropriate, particularly when using the carbohydrate counting method for meal planning. There is no evidence that the amounts of sugar alcohol likely to be consumed will result in significant reduction in energy intake or long-term improvement in glycemia. The use of sugar alcohols appears to be safe.
The FDA has approved five nonnutritive sweeteners for use in the U.S.: acesulfame potassium, aspartame, neotame, saccharin, and sucralose. All have undergone rigorous scrutiny and have been shown to be safe when consumed by the public, including people with diabetes and women who are pregnant.
Since diabetes may be a state of increased oxidative stress, there has been interest in prescribing antioxidant vitamins to individuals with diabetes. While observational studies have shown a correlation between dietary or supplemental consumption of antioxidants and a variety of clinical outcomes such as prevention of disease states, large placebo-controlled clinical trials have failed to show a benefit and, in some instances, have suggested adverse effects.
Several small studies have suggested a role for chromium supplementation in the management of glucose intolerance, body weight, GDM, and corticosteroid-induced diabetes. Also, placebo-controlled studies conducted in China found that chromium supplementation had beneficial effects on glycemia, although it is important to note that the study population in China may have had marginal baseline chromium status. A recent FDA statement indicated that there is insufficient evidence to support any of the proposed health claims for chromium supplementation. The FDA concluded that although a small study suggested that chromium picolinate may reduce the risk of insulin resistance, the existence of a relationship between chromium picolinate and either insulin resistance or type 2 diabetes was highly uncertain (see “chromium picolinate and insulin resistance” at www.cfsan.fda.gov/ dms/qhccr.html). In addition, a meta-analysis of randomized controlled trials suggested no benefit of chromium picolinate supplementation in reducing body weight.
For individuals with diabetes, the same precautions apply regarding the use of alcohol that apply to the general population. If individuals choose to use alcohol, alcohol-containing beverages should be limited to a moderate amount (less than one drink per day for adult women and less than two drinks per day for adult men). One alcohol containing beverage is defined as 12 oz beer, 5 oz wine, or 1.5 oz distilled spirits. Each contains 15 g alcohol.
AMERICAN DIABETES ASSOCIATION
DIABETES CARE, VOLUME 27, SUPPLEMENT 1, JANUARY 2004
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