This Physician’s Weekly feature covering nutritional recommendations and interventions for diabetes was completed in cooperation with the experts at the American Diabetes Association.
Medical nutrition therapy (MNT) is an important part of preventing prediabetes and diabetes, managing existing diabetes, and preventing or slowing the rate of the development of diabetes complications. MNT is also an integral component of diabetes self-management education and training. The goals of MNT are to achieve and maintain healthy A1C, blood pressure, and cholesterol levels by modifying the intake of nutrients and improving lifestyle behaviors. “The United States has about 57 million people with pre-diabetes, and most of these people have problems with being overweight and obese,” says Wahida Karmally, DrPH, RD, CDE, CLS, FNLA. “In addition, people with diagnosed diabetes are often already overweight or obese. Using MNT and increasing physical activity are paramount to managing these individuals.”
Clinical practice recommendations on MNT, which are based on scientific evidence, have recently been updated by the American Diabetes Association. Available at http://care.diabetesjournals.org, the recommendations can assist clinicians as they provide MNT to patients and offer strategies for specific patient groups (Table 1). “With MNT, it’s important to address individual nutrition needs,” says Dr. Karmally. “That requires taking into account personal and cultural preferences as well as willingness to change. Another goal is to help people maintain the pleasure of eating by only limiting food choices when indicated by scientific evidence.”
Assessing the Evidence
Clinical trials and outcome studies of MNT have reported decreases in A1C of about 1% in type 1 diabetes and 1% to 2% in type 2 diabetes, depending on the duration of the disease. The American Diabetes Association notes that the first nutrition priority in MNT is to encourage patients to implement lifestyle strategies that will improve glycemia, dyslipidemia, and blood pressure (Table 2). Structured, intensive lifestyle programs involving participant education, individualized counseling, reduced dietary energy and fat intake, regular physical activity, and frequent participant contact are necessary to produce long-term weight loss.
“Many patients fail to understand the connection between losing weight and managing diabetes or preventing pre-diabetes,” Dr. Karmally points out. “Weight loss is necessary more for their overall health than for cosmetic value. Physicians need to articulate this to patients and counsel them as to how they can accomplish weight loss. Simply telling patients to lose weight sets them up for failure because they often don’t know how to start or what they should be doing to lose weight. We should encourage even small health changes and provide concrete recommendations to get there. For example, instead of saying that patients need to cut back on their fat intake, explain to them that their dinner plate should be half vegetables, a quarter lean meat, fish, or chicken, and a quarter whole grains. This can help them visualize the advice.”
People who have pre-diabetes or diabetes should receive individualized MNT. While utilizing MNT, it is important to consider the individual being treated. “If a young person has type 1 diabetes, MNT will need to be adjusted to account for body development and growth that comes with age,” explains Dr. Karmally. “If a woman is pregnant and has diabetes, we must think of the woman and her fetus. For people with type 2 diabetes who are overweight or obese, caloric reductions and nutrient supplementation are likely to be different than for other patients with diabetes. Furthermore, cultural differences should be considered. When creating MNT plans, it’s important to ask about what types of foods and snacks patients like to eat and what their families like to eat. After getting this information, healthcare providers can then help patients find ways to eat healthier without giving up their favorite foods.”
Physicians can play an integral role by advising their patients to visit registered dietitians or diabetes educators who are familiar with the components of MNT, Dr. Karmally says. “Research suggests that patients are more likely to follow through with MNT when they are recommended to do so by their physician. Physicians are powerful motivators and can set the stage for successful MNT by encouraging their patients to collaborate with their diabetes care team.”
Lifestyle changes typically do not happen overnight, says Dr. Karmally, and ongoing support is crucial. “Habits form over many years, so clinicians must understand that it may take time before patients make sustained changes in their nutrition and lifestyle and then maintain these changes. Physicians should take a patient-centered approach and provide individuals with the education and information they need to prepare them to take action. Diabetes is a chronic disease that requires ongoing, tailored counseling to ensure that nutritional and lifestyle changes are upheld by patients for the long haul.”
American Diabetes Association, Bantle JP, Wylie-Rosett J, Albright AL, et al. Nutrition recommendations and interventions for diabetes: a position statement of the American Diabetes Association. Diabetes Care. 2008;31(Suppl 1):S61-S78. Available at: http://care.diabetesjournals.org/content/31/Supplement_1/S61.full.
American Diabetes Association. Standards of Medical Care—2010. Diabetes Care. 2010;33(Suppl 1):S11-S61. Available at: http://care.diabetesjournals.org/content/33/Supplement_1/S11.full.
Sigal RJ, Kenny GP, Wasserman DH, Castaneda-Sceppa C, White RD. Physical activity/exercise and type 2 diabetes: a consensus statement from the American Diabetes Association. Diabetes Care. 2006;29:1433–1438.
Pastors JG, Warshaw H, Daly A, Franz M, Kulkarni K. The evidence for the effectiveness of medical nutrition therapy in diabetes management. Diabetes Care. 2002;25:608-613.
American Diabetes Association: Nutrition principles and recommendations in diabetes (Position Statement). Diabetes Care. 2004;27(Suppl 1):S36-S46.