Diabetes Prevention

PDM: Executive Summary of Recommendations (2014)

Executive Summary of Recommendations

Below are the major recommendations and ratings for the Academy of Nutrition and Dietetics Prevention of Type 2 Diabetes (PDM) Evidence-Based Nutrition Practice Guideline. More detail (including the evidence analysis supporting these recommendations) is available on this website to Academy members and EAL subscribers by clicking Major Recommendations.

To see a description of the Academy Recommendation Rating Scheme (Strong, Fair, Weak, Consensus, Insufficient Evidence), click here.

The Prevention of Type 2 Diabetes Recommendations are listed below. [Note: If you mouse-over underlined acronyms and terms, a definition will pop up.]

  • Screening and Referral
    PDM: Screen for Type 2 Diabetes Risk
    The registered dietitian nutritionist (RDN) should ensure that all individuals are screened for risk of type 2 diabetes, using a recognized screening tool (such as the American Diabetes Association Type 2 Diabetes Risk Test, http://www.diabetes.org/diabetes-basics/prevention/diabetes-risk-test/). The prevalence and socioeconomic burden of type 2 diabetes and associated co-morbidities are rising worldwide, and individuals who are at high risk for type 2 diabetes should be prioritized for intensive intervention to delay the onset of disease.    
    Consensus
    Imperative
    PDM: Determine Appropriate Action Based on Screening
    The registered dietitian nutritionist (RDN) should collaborate with other healthcare providers to determine the appropriate actions to be taken, based on the results of the screening:
    • Re-screening three years later if tests are normal
    • General advice about risk factors and development of diabetes
    • Referral to healthcare provider for laboratory work and other medical tests
    • Referral for weight reduction, including medical nutrition therapy (MNT) for Adult Weight Management
    • Referral for type 2 diabetes prevention program, including MNT for Prevention of Type 2 Diabetes in high-risk groups
    • Referral for diabetes therapy, including MNT for Diabetes.
    The prevalence and socioeconomic burden of type 2 diabetes and associated co-morbidities are rising worldwide, and individuals who are at high risk for type 2 diabetes should be prioritized for intensive intervention to delay the onset of disease.
    Consensus
    Imperative
    PDM: MNT for Prevention of Type 2 Diabetes in High Risk Groups
    The registered dietitian nutritionist (RDN) should provide medical nutrition therapy (MNT) encounters for individuals who are at high risk for type 2 diabetes and increase the frequency of encounters to optimize outcomes. In adults with metabolic syndrome, research regarding the impact of medical nutrition therapy (MNT) reported significant improvements:
    • Decreased fasting blood glucose by 2.5mg to 9mg per dL (0.1mmol to 0.5mmol per L)
    • Decreased A1C by 0.12% to 0.23% 
    • Decreased triglycerides by 21mg to 35mg per dL (0.2mmol to 0.4mmol per L) 
    • Increased HDL cholesterol by 2.4mg per dL (0.06mmol per L)
    • Decreased body weight by 2.5kg to 4.1kg
    • Decreased waist circumference by 1.9cm to 4.8cm
    • Decreased systolic blood pressure by 4.9mm Hg.
    In individuals with prediabetes, research regarding the impact of medical nutrition therapy (MNT) reported significant improvements:
    • Decreased fasting blood glucose by 2mg to 9mg per dL (0.1mmol to 0.5mmol per L)
    • Decreased two-hour post-prandial blood glucose by 9mg to 16.2mg per dL (0.5mmol to 0.9mmol per L).
    • Decreased waist circumference by 3.8 - 5.9 cm
    In addition, studies reported that increased frequency of visits resulted in greater improvements in certain metabolic and anthropometric outcomes.
    Strong
    Imperative
  • Nutrition Assessment
    PDM: Assessment in High-risk Groups
    • The registered dietitian nutritionist (RDN) should assess the following, but not limited to, for individuals who are at high risk for type 2 diabetes:
      • Glycemia (fasting blood glucose, two-hour post-prandial blood glucose and A1C)
      • Anthropometrics (weight, BMI, waist circumference, waist-to-hip ratio)
      • CVD risk factors (lipid profile and blood pressure)
      • Physical activity
      • Medications and supplements
      • Dietary factors
      • History of depression
      • Obesigenic/diabetogenic environment
      • Socio-economic status (SES).
    • These factors allow the RDN to determine the appropriate interventions to prevent type 2 diabetes.
    Consensus
    Imperative
  • Nutrition Intervention
    PDM: Weight Loss and Prevention of Type 2 Diabetes
    • For individuals who are at high risk for type 2 diabetes who are overweight or obese, the registered dietitian nutritionist (RDN) should prescribe a weight-reducing diet and support weight loss using evidence-based nutrition practice guidelines
    • In adults with metabolic syndrome, research regarding a weight loss achieved via lifestyle modification over at least a three-month period ranging from 1.1kg to 13kg reported significant improvements:
      • Decreased A1C by 0.12% to 0.3%
      • Decreased triglycerides by 20mg to 132mg per dL (0.23mmol to 1.5mmol per L)
      • Decreased waist circumference by 1.5cm to 11cm
      • Decreased systolic blood pressure by 4.9mm Hg to 10mm Hg.
    • In individuals with prediabetes, research regarding a weight loss achieved via lifestyle modification over at least a three-month period ranging from 2.6kg to 7.1kg reported significant improvements:
      • Decreased fasting glucose levels by 2.2mg to 9.2mg per dL (0.12mmol to 0.5mmol per L)
      • Decreased triglyceride levels by 30.9mg per dL (0.35mmol per L)
      • Decreased waist circumference by 1.3cm to 5.9cm
      • Decreased systolic blood pressure 3.5mm Hg to 6mm Hg and diastolic blood pressure by 5mm Hg.
    • In individuals with prediabetes, research regarding a weight loss achieved via bariatric surgery of up to 47kg or 41% of excess BMI over a period of three to five years reported significant improvements:
      • Decreased fasting glucose levels by 16.2mg to 20.9mg per dL (0.9mmol to 1.16mmol per L)
      • Decreased two-hour post-prandial glucose levels by 16mg per dL (0.9mmol per L)
      • Decreased A1C by 0.5%.
      • Decreased triglyceride levels by 70.6mg per dL (0.8mmol per L)
      • Increased HDL cholesterol levels by 1.9mg per dL (0.05mmol per L)
      • Decreased systolic blood pressure by 6mm Hg.
    Strong
    Conditional
    PDM: Nutrition Prescription for Macronutrients
    The registered dietitian nutritionist (RDN) should individualize the nutrition prescription for macronutrients based on the Dietary Reference Intakes (DRI), which are 10% to 35% protein, 20% to 35% fat, and 45% to 65% carbohydrate, for individuals who are at high risk for type 2 diabetes. Research is inconclusive regarding the effect of macronutrient distribution as a percentage of energy, independent of weight loss, on outcomes in both adults with metabolic syndrome and individuals with prediabetes, related to the varying macronutrient distributions in study diets.
    Fair
    Imperative
    PDM: Fiber and Prevention of Type 2 Diabetes
    The registered dietitian nutritionist (RDN) should encourage individuals who are at high risk for type 2 diabetes to consume fiber at the level recommended by the USDA Dietary Guidelines (14g per 1,000kcal). Limited research regarding fiber intake, independent of weight loss, reported no significant impact on outcomes in adults with metabolic syndrome or individuals with prediabetes. However, a high-fiber diet can help reduce body weight and therefore reduce the risk of type 2 diabetes.

       
    Fair
    Imperative
    PDM: Whole Grains and Prevention of Type 2 Diabetes
    The registered dietitian nutritionist (RDN) should encourage individuals who are at high risk for type 2 diabetes to consume whole grains at the level recommended by the USDA Dietary Guidelines (one-half of grain intake). Limited research regarding whole grain intake, independent of weight loss, reported no significant impact on outcomes in adults with metabolic syndrome or individuals with prediabetes. However, a high-fiber diet can help reduce body weight and therefore reduce the risk of type 2 diabetes.

       
    Weak
    Imperative
    PDM: Vegetable-Based Protein and Prevention of Type 2 Diabetes
    If the consumption of vegetable-based protein is proposed for the prevention of type 2 diabetes, the registered dietitian nutritionist (RDN) should advise individuals who are at high risk for type 2 diabetes that the source of dietary protein alone, without weight loss, may or may not be beneficial. There were no studies identified to evaluate the impact of vegetable-based protein intake vs. animal-based protein intake, independent of weight loss, on outcomes in adults with metabolic syndrome or individuals with prediabetes.
     
    Insufficient Evidence
    Conditional
    PDM: Type of Fat and Prevention of Type 2 Diabetes
    The registered dietitian nutritionist (RDN) should educate individuals who are at high risk for type 2 diabetes that the type of fat consumption alone, without weight loss, may not prevent type 2 diabetes. Most studies regarding the type of fat intake, independent of weight loss, reported no significant impact on outcomes in adults with metabolic syndrome or individuals with prediabetes.
    Fair
    Imperative
    PDM: Fruits and Vegetables and Prevention of Type 2 Diabetes
    If modifying the consumption of fruits and vegetables is proposed for the prevention of type 2 diabetes, the registered nutritionist (RDN) should advise individuals who are at high risk for type 2 diabetes that fruit and vegetable consumption alone, without weight loss, may or may not be beneficial. There were no studies identified to evaluate the impact of fruit and vegetable intake, independent of weight loss, on outcomes in adults with metabolic syndrome or individuals with prediabetes.
    Insufficient Evidence
    Conditional
    PDM: Sugar and Prevention of Type 2 Diabetes
    If avoiding the consumption of sugar is proposed for the prevention of type 2 diabetes, the registered dietitian nutritionist (RDN) should advise individuals who are at high risk for type 2 diabetes that limiting sugar consumption, without weight loss, may or may not be beneficial. There were no studies identified to evaluate the impact of sugar intake, independent of weight loss, on outcomes in adults with metabolic syndrome or individuals with prediabetes. However, higher intake of added sugars may contribute to higher energy intake and increased body weight, and therefore increase the risk of type 2 diabetes.



     
    Insufficient Evidence
    Conditional
    PDM: Glycemic Index/Glycemic Load and Prevention of Type 2 Diabetes
    If the use of glycemic index/glycemic load is proposed for the prevention of type 2 diabetes, the registered dietitian nutritionist (RDN) should advise individuals who are at high risk for type 2 diabetes that a reduction in glycemic index/glycemic load alone, without weight loss, may or may not be beneficial. Limited research in both adults with metabolic syndrome and individuals with prediabetes reported that a reduction in glycemic index/load results in improvements in postprandial blood glucose values, independent of weight loss.
    Weak
    Conditional
    PDM: Physical Activity and Prevention of Type 2 Diabetes
    • The registered dietitian nutritionist (RDN) should educate individuals who are at high risk for type 2 diabetes that physical activity alone, without weight loss and dietary change, has limited impact on the prevention of type 2 diabetes
    • However, in adults with metabolic syndrome, research regarding moderate intensity physical activity, at a level of 135 to 180 minutes per week, independent of weight loss and dietary change, reported significant improvements:
      • Decreased triglycerides by 33mg per dL (0.37mmol per L)
      • Decreased waist circumference by 3cm
      • Decreased systolic blood pressure by 6mm Hg
      • Decreased diastolic blood pressure by 3mm Hg.
     
    Weak
    Imperative
    PDM: Nutrition-related Effects of Medications
    For individuals at high risk for type 2 diabetes who have been prescribed medications, the registered dietitian nutritionist (RDN) should educate on potential food and drug interactions and nutrition-related adverse effects. Pharmacotherapy may be prescribed to treat various aspects related to the prevention of diabetes; however, these medications may be poorly tolerated and have contraindications.  
    Strong
    Conditional
    PDM: Nutrition Counseling
    The registered dietitian nutritionist (RDN) should counsel individuals who are at high risk for type 2 diabetes based on established, well-defined behavior change strategies, such as (but not limited to) the following:
    • Goal setting
    • Motivational interviewing
    • Practice of new behavior
    • Relapse prevention
    • Self-monitoring
    • Self-talk
    • Social support
    • Time management.
    These strategies are associated with initiation and maintenance of behavior change.
    Strong
    Imperative
    PDM: Coordination of Care
    For individuals who are at high risk for type 2 diabetes, the registered dietitian nutritionist (RDN) should implement medical nutrition therapy (MNT) and coordinate care with a multi-disciplinary team and important others (e.g., family, friends and colleagues) in a wide variety of settings. This approach is necessary to effectively integrate MNT into overall management for individuals who are at high risk for type 2 diabetes.      
    Strong
    Imperative
  • Nutrition Monitoring and Evaluation
    PDM: Monitoring and Evaluation in High-risk Groups
    • The registered dietitian nutritionist (RDN) should monitor and evaluate the following, but not limited to, for individuals who are at high risk for type 2 diabetes:
      • Glycemia (fasting blood glucose, two-hour post-prandial blood glucose and A1C)
      • Anthropometrics (weight, BMI, waist circumference, waist-to-hip ratio)
      • CVD risk factors (lipid profile and blood pressure)
      • Physical activity
      • Medications and supplements
      • Dietary factors.
    • These factors allow the RDN to evaluate the effectiveness of medical nutrition therapy (MNT) for the prevention of type 2 diabetes in high-risk groups.
    Consensus
    Imperative