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Recommendations Summary

PDM: Whole Grains and Prevention of Type 2 Diabetes 2014

Click here to see the explanation of recommendation ratings (Strong, Fair, Weak, Consensus, Insufficient Evidence) and labels (Imperative or Conditional). To see more detail on the evidence from which the following recommendations were drawn, use the hyperlinks in the Supporting Evidence Section below.

• Recommendation(s)

  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.
  
   

  Rating: Weak
  Imperative

  • Risks/Harms of Implementing This Recommendation

    None.

  • Conditions of Application

    Research on synergistic effects of nutrients was not evaluated.

  • Potential Costs Associated with Application

    The costs of medical nutrition therapy (MNT).

  • Recommendation Narrative

    A total of two studies were included in the evidence analysis for this recommendation:

    • Two positive-quality randomized controlled trials (RCT) (Katcher et al, 2008; Lankinen et al, 2011).

    In Adults With Metabolic Syndrome

    • Glycemic-related outcomes (FBG, random BG, two-hour post-prandial BG, A1C):
      • Limited research reports no significant impact of whole or refined grains, independent of weight loss, on fasting blood glucose or two-hour post-prandial blood glucose levels in adults with metabolic syndrome
      • Additional longer-term intervention studies are needed to ascertain an effect of whole or refined grains on glycemic-related outcomes in adults with metabolic syndrome with or without meeting the metabolic syndrome criteria for impaired glucose tolerance and impaired fasting glucose
      • Evidence is based on the following: Katcher et al, 2008.
    • Lipid outcomes (TG, HDL):
      • Limited research reports no significant impact of whole or refined grains, independent of weight loss, on triglyceride or HDL cholesterol levels in adults with metabolic syndrome
      • Additional longer-term intervention studies are needed to ascertain an effect of whole or refined grains on lipid outcomes in adults with metabolic syndrome with or without meeting the metabolic syndrome criteria for lipid levels
      • Evidence is based on the following: Katcher et al, 2008.
    • Anthropometric outcomes (WC, WHR):
      • Limited research reports no significant impact of whole or refined grains, independent of weight loss, on waist circumference in adults with metabolic syndrome
      • Additional longer-term intervention studies are needed to ascertain an effect of whole or refined grains on anthropometric outcomes in adults with metabolic syndrome with or without meeting the metabolic syndrome criteria for anthropometric measures
      • Evidence is based on the following: Katcher et al, 2008.
    • Blood pressure outcomes:
      • Limited research reports no significant impact of whole or refined grains, independent of weight loss, on systolic or diastolic blood pressure in adults with metabolic syndrome
      • Additional longer-term intervention studies are needed to ascertain the effect of whole or refined grains on blood pressure in adults with metabolic syndrome with or without meeting the metabolic syndrome criteria for blood pressure
      • Evidence is based on the following: Katcher et al, 2008.
    • Renal outcomes:
      • There were no studies identified to evaluate the impact of whole or refined grains, independent of weight loss, on renal outcomes in adults with metabolic syndrome
      • Intervention studies are needed to ascertain an effect of whole or refined grains on renal outcomes in adults with metabolic syndrome with or without meeting the metabolic syndrome criteria for renal measures. 

    In Individuals With Prediabetes

    • Glycemic-related outcomes (FBG, random BG, two-hour post-prandial BG, A1C):
      • Limited research reports no significant impact of whole or refined grains, independent of weight loss, on fasting blood glucose or two-hour post-prandial blood glucose in individuals with prediabetes
      • Additional intervention studies are needed to ascertain the effect of whole or refined grains on glycemic-related outcomes in individuals with prediabetes
      • Evidence is based on the following: Lankinen et al, 2011.
    • Lipid outcomes (TG, HDL):
      • There were no studies identified to evaluate the impact of whole or refined grains, independent of weight loss, on lipid outcomes in individuals with prediabetes
      • Intervention studies are needed to ascertain the effect of whole or refined grains on lipid outcomes in individuals with prediabetes. 
    • Anthropometric outcomes (WC, WHR):
      • There were no studies identified to evaluate the impact of whole or refined grains, independent of weight loss, on anthropometric outcomes in individuals with prediabetes
      • Intervention studies are needed to ascertain the effect of whole or refined grains on anthropometric outcomes in individuals with prediabetes. 
    • Blood pressure outcomes:
      • There were no studies identified to evaluate the impact of whole or refined grains, independent of weight loss, on blood pressure in individuals with prediabetes
      • Intervention studies are needed to ascertain the effect of whole or refined grains on blood pressure in individuals with prediabetes.  

    From Primary Prevention of Type 2 Diabetes Recommendations from the American Diabetes Association Standards of Medical Care, 2014

    Individuals at high risk for type 2 diabetes should be encouraged to achieve the U.S. Department of Agriculture (USDA) recommendation for dietary fiber (14g fiber per 1, 000kcal) and foods containing whole grains (one half of grain intake) (Grade B).

    From Project IMAGE European Evidence-Based Guideline for the Prevention of Type 2 Diabetes, 2010

    • A diet with high fiber (more than 15g per 1, 000kcal), moderate fat (less than 35% of total energy), reduced saturated and trans fat (less than 10% of total energy) can lower body weight and reduce the risk of T2D and is therefore recommended (Grade B)
    • Comorbidities, particular MetS, should be monitored and taken into account when planning the diet (Grade C).
    • Currently there is no evidence from long-term prevention studies that reducing total dietary carbohydrate prevents T2D. Carbohydrate sources should mainly be whole-grain cereal, fruit, vegetables and legumes (Grade C).

  • Recommendation Strength Rationale

    For Adults with Metabolic Syndrome

    • Grade III evidence is available for the conclusion statements regarding the impact of whole or refined grains intake, independent of weight loss, on the following outcomes:
      • Glycemic-related outcomes (such as fasting blood glucose, random blood glucose, two-hour post-prandial blood glucose, A1C):
      • Lipid (TG, HDL)
      • Anthropometric measures (WC, WHR)
      • Blood pressure.
    • Grade V evidence is available for the conclusion statements regarding the impact of whole or refined grains intake, independent of weight loss, on the following outcomes: Renal measures.

    For Individuals with Prediabetes

    • Grade III evidence is available for the conclusion statements regarding the impact of whole or refined grains intake, independent of weight loss, on the following outcomes: Glycemic-related outcomes (such as fasting blood glucose, random blood glucose, two-hour post-prandial blood glucose, A1C)
    • Grade V evidence is available for the conclusion statements regarding the impact of whole or refined grains intake, independent of weight loss, on the following outcomes:
      • Lipid (TG, HDL)
      • Anthropometric measures (WC, WHR)
      • Blood pressure.

    From Primary Prevention of Type 2 Diabetes Recommendations from the American Diabetes Association Standards of Medical Care, 2014

    • The Academy of Nutrition and Dietetics Prevention of Type 2 Diabetes Work Group concurs with the references cited
    • Evidence in support of the recommendation was grade B.

    From Project IMAGE European Evidence-Based Guideline for the Prevention of Type 2 Diabetes, 2010

    • The Academy of Nutrition and Dietetics Prevention of Type 2 Diabetes Work Group concurs with the references cited
    • Evidence in support of the recommendation was grades B and C.

  • Minority Opinions

    Consensus reached.

• Supporting Evidence

  The recommendations were created from the evidence analysis on the following questions. To see detail of the evidence analysis, click the blue hyperlinks below (recommendations rated consensus will not have supporting evidence linked).

  In individuals with prediabetes, what is the impact of whole or refined grains, independent of weight loss, on glycemic-related outcomes (such as fasting blood glucose, random blood glucose, two-hour post-prandial blood glucose, A1C)?
  
  In individuals with prediabetes, what is the impact of whole or refined grains, independent of weight loss, on lipid outcomes (TG, HDL)?
  
  In individuals with prediabetes, what is the impact of whole or refined grains, independent of weight loss, on anthropometric outcomes (WC, WHR)?
  
  In individuals with prediabetes, what is the impact of whole or refined grains, independent of weight loss, on blood pressure?
  
  In adults with metabolic syndrome, what is the impact of whole or refined grains, independent of weight loss, on glycemic-related outcomes (such as fasting blood glucose, random blood glucose, two-hour post-prandial blood glucose, A1C)?
  
  In adults with metabolic syndrome, what is the impact of whole or refined grains, independent of weight loss, on lipid outcomes (TG, HDL)?
  
  In adults with metabolic syndrome, what is the impact of whole or refined grains, independent of weight loss, on anthropometric outcomes (WC, WHR)?
  
  In adults with metabolic syndrome, what is the impact of whole or refined grains, independent of weight loss, on blood pressure?
  
  In adults with metabolic syndrome, what is the impact of whole or refined grains, independent of weight loss, on renal outcomes?

  • References

    Lankinen M, Schwab U, Kolehmainen M, Paananen J, Poutanen K, Mykkanen H, Seppanen-Laakso T, Gylling H, Uusitupa M, Oresic M. Whole grain products, fish and bilberries alter glucose and lipid metabolism in a randomized, controlled trial: The Sysdimet study. PLos One. 2011; 6(8): e22646.
    
    Katcher HI, Legro RS, Kunselman AR, Gillies PJ, Demers LM, Bagshaw DM, Kris-Etherton PM. The effects of a whole grain-enriched hypocaloric diet on cardiovascular disease risk factors in men and women with metabolic syndrome. Am J Clin Nutr. 2008; 87: 79-90.

  • References not graded in Academy of Nutrition and Dietetics Evidence Analysis Process

    American Diabetes Association. Standards of medical care in diabetes: 2014. Diabetes Care. 2014; 37 Suppl 1: S14-S80.
    
    Lindström J, Neumann A, Sheppard KE, Gilis-Januszewska A, Greaves CJ, Handke U, Pajunen P, Puhl S, Pölönen A, Rissanen A, Roden M, Stemper T, Telle-Hjellset V, Tuomilehto J, Velickiene D, Schwarz PE, Acosta T, Adler M, AlKerwi A, Barengo N, Barengo R, Boavida JM, Charlesworth K, Christov V, Claussen B, Cos X, Cosson E, Deceukelier S, Dimitrijevic-Sreckovic V, Djordjevic P, Evans P, Felton AM, Fischer M, Gabriel-Sanchez R, Gilis-Januszewska A, Goldfracht M, Gomez JL, Greaves CJ, Hall M, Handke U, Hauner H, Herbst J, Hermanns N, Herrebrugh L, Huber C, Hühmer U, Huttunen J, Jotic A, Kamenov Z, Karadeniz S, Katsilambros N, Khalangot M, Kissimova-Skarbek K, Köhler D, Kopp V, Kronsbein P, Kulzer B, Kyne-Grzebalski D, Lalic K, Lalic N, Landgraf R, Lee-Barkey YH, Liatis S, Lindström J, Makrilakis K, McIntosh C, McKee M, Mesquita AC, Misina D, Muylle F, Neumann A, Paiva AC, Pajunen P, Paulweber B, Peltonen M, Perrenoud L, Pfeiffer A, Pölönen A, Puhl S, Raposo F, Reinehr T, Rissanen A, Robinson C, Roden M, Rothe U, Saaristo T, Scholl J, Schwarz PE, Sheppard KE, Spiers S, Stemper T, Stratmann B, Szendroedi J, Szybinski Z, Tankova T, Telle-Hjellset V, Terry G, Tolks D, Toti F, Tuomilehto J, Undeutsch A, Valadas C, Valensi P, Velickiene D, Vermunt P, Weiss R, Wens J, Yilmaz T. Take action to prevent diabetes: The IMAGE toolkit for the prevention of type 2 diabetes in Europe. Horm Metab Res. 2010 Apr; 42 Suppl 1: S37-S55.

    Pajunen P, Landgraf R, Muylle F, Neumann A, Lindström J, Schwarz PE, Peltonen M, Acosta T, Adler M, AlKerwi A, Barengo N, Barengo R, Boavida JM, Charlesworth K, Christov V, Claussen B, Cos X, Cosson E, Deceukelier S, Dimitrijevic-Sreckovic V, Djordjevic P, Evans P, Felton AM, Fischer M, Gabriel-Sanchez R, Gilis-Januszewska A, Goldfracht M, Gomez JL, Greaves CJ, Hall M, Handke U, Hauner H, Herbst J, Hermanns N, Herrebrugh L, Huber C, Hühmer U, Huttunen J, Jotic A, Kamenov Z, Karadeniz S, Katsilambros N, Khalangot M, Kissimova-Skarbek K, Köhler D, Kopp V, Kronsbein P, Kulzer B, Kyne-Grzebalski D, Lalic K, Lalic N, Landgraf R, Lee-Barkey YH, Liatis S, Lindström J, Makrilakis K, McIntosh C, McKee M, Mesquita AC, Misina D, Muylle F, Neumann A, Paiva AC, Pajunen P, Paulweber B, Peltonen M, Perrenoud L, Pfeiffer A, Pölönen A, Puhl S, Raposo F, Reinehr T, Rissanen A, Robinson C, Roden M, Rothe U, Saaristo T, Scholl J, Schwarz PE, Sheppard KE, Spiers S, Stemper T, Stratmann B, Szendroedi J, Szybinski Z, Tankova T, Telle-Hjellset V, Terry G, Tolks D, Toti F, Tuomilehto J, Undeutsch A, Valadas C, Valensi P, Velickiene D, Vermunt P, Weiss R, Wens J, Yilmaz T. Quality indicators for the prevention of type 2 diabetes in Europe: IMAGE. Horm Metab Res. 2010 Apr; 42 Suppl 1: S56-S63.

    Paulweber B, Valensi P, Lindström J, Lalic NM, Greaves CJ, McKee M, Kissimova-Skarbek K, Liatis S, Cosson E, Szendroedi J, Sheppard KE, Charlesworth K, Felton AM, Hall M, Rissannen A, Tuomilehto J, Schwarz PE, Roden M, for the Writing Group: Paulweber M, Stadlmayr A, Kedenko L, Katsilambros N, Makrilakis K, Kamenov Z, Evans P, Gilis-Januszewska A, Lalic K, Jotic A, Djordevic P, Dimitrijevic-Sreckovic V, Hühmer U, Kulzer B, Puhl S, Lee-Barkey YH, AlKerwi A, Abraham C, Hardeman W, on behalf of the IMAGE Study Group: Acosta T, Adler M, AlKerwi A, Barengo N, Barengo R, Boavida JM, Charlesworth K, Christov V, Claussen B, Cos X, Cosson E, Deceukelier S, Dimitrijevic-Sreckovic V, Djordjevic P, Evans P, Felton AM, Fischer M, Gabriel-Sanchez R, Gilis-Januszewska A, Goldfracht M, Gomez JL, Greaves CJ, Hall M, Handke U, Hauner H, Herbst J, Hermanns N, Herrebrugh L, Huber C, Hühmer U, Huttunen J, Jotic A, Kamenov Z, Karadeniz S, Katsilambros N, Khalangot M, Kissimova-Skarbek K, Köhler D, Kopp V, Kronsbein P, Kulzer B, Kyne-Grzebalski D, Lalic K, Lalic N, Landgraf R, Lee-Barkey YH, Liatis S, Lindström J, Makrilakis K, McIntosh C, McKee M, Mesquita AC, Misina D, Muylle F, Neumann A, Paiva AC, Pajunen P, Paulweber B, Peltonen B, Perrenoud L, Pfeiffer A, Pölönen A, Puhl S, Raposo F, Reinehr T, Rissanen A, Robinson C, Roden M, Rothe U, Saaristo T, Scholl J, Schwarz PE, Sheppard KE, Spiers S, Stemper T, Stratmann B, Szendroedi J, Szybinski Z, Tankova T, Telle-Hjellset V, Terry G, Tolks D, Toti F, Tuomilehto J, Undeutsch A, Valadas C, Valensi P, Velickiene D, Vermunt P, Weiss R, Wens J, Yilmaz T. A European evidence-based guideline for the prevention of type 2 diabetes. Horm Metab Res. 2010 Apr; 42 Suppl 1: S3-S36.