• Intervention
    What is the relationship between carbohydrate intake and metabolic outcomes in persons with type 1 and type 2 diabetes?
    • Conclusion

      Nine studies investigated the relationship between carbohydrate intake and metabolic control in type 1 and type 2 diabetes.  Two studies in subjects with Type I diabetes based the adjustment of mealtime insulin to match planned carbohydrate intake and three studies based on day-to-day consistency in carbohydrate intake resulted in improved glycemic control.  Of four studies evaluating differing percentages of carbohydrate, the evidence was inconclusive.

    • Grade: I
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.
    • Search Plan and Results: Carbohydrate Intake 2007
       
  • Basic Research
    What is the relationship between fiber and metabolic outcomes in persons with type 1 and type 2 diabetes?
    • Conclusion
      There is inconclusive evidence that increasing dietary fiber will influence glycemic outcome in people with diabetes.  
       
      Two studies with higher fiber and lower fiber diets both containing similar macronutrient percents of energy  showed no significant difference between diets for A1C, and one study showed a 2% reduction in A1C only in subjects compliant with the 50 gram fiber diet. Three studies found 24-hr glycemic profiles significantly lower on the higher fiber diet vs the lower fiber diet and one study showed significantly lower postprandial glucose levels on the higher fiber vs the lower fiber diet. Two studies with higher fiber and lower fiber diets having different macronutrient percents of energy showed no change in A1C between diets; however, two studies showed significant improvement in A1C with the higher fiber diet vs the lower fiber diet. Three studies found no change in fasting blood glucose between diets, and one study found significant improvement in FBG for the higher fiber vs the lower fiber diet. One cross-sectional study found that fiber intake was inversely related to A1C and the other showed no relationship.
       
      When the above studies are divided according to environment (controlled or free living), type of diabetes, or “good” or “poor” control, they showed the same  results. 

       

      There appears to be conclusive evidence that higher fiber diets will lower total cholesterol significantly vs lower fiber diets. In eight studies lipids were a measured outcome.   Seven studies showed a significant decrease in total cholesterol in the higher fiber group compared to the lower fiber group and one showed no change. Three of the eight studies reported significantly reduced HDL-cholesterol. 

    • Grade: I
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.
    • Search Plan and Results: Dietary Fiber 2007
       
    What is the relationship between glycemic index and metabolic outcomes in persons with type 1 and type 2 diabetes?
    • Conclusion

      Fifteen short-term studies ranging from two to 12 weeks and one longer term (one year) studies report mixed effects on A1C levels.  These studies are complicated by differing definitions of "high GI" and "low GI" diets or quartiles, as well as possible confounding dietary factors. 

    • Grade: II
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.
    • Search Plan and Results: Glycemic Index/Glycemic Load 2007
       
    What is the relationship between sucrose and metabolic outcomes in persons with type 1 and type 2 diabetes?
    • Conclusion

      Sucrose intakes of 10 percent to 35 percent of total energy intake do not have a negative effect on glycemic or lipid responses in persons with either type 1 or type 2 diabetes when sucrose is substituted for isocaloric amounts of starch. Ten randomized crossover/controlled studies, four non-randomized crossover studies and one cross-over study examined the effect of sucrose on glycemic control. All but one study showed no effect of sucrose.

    • Grade: I
      • Grade I means there is Good/Strong evidence supporting the statement;
      • Grade II is Fair;
      • Grade III is Limited/Weak;
      • Grade IV is Expert Opinion Only;
      • Grade V is Not Assignable.
      • High (A) means we are very confident that the true effect lies close to that of the estimate of the effect;
      • Moderate (B) means we are moderately confident in the effect estimate;
      • Low (C) means our confidence in the effect estimate is limited;
      • Very Low (D) means we have very little confidence in the effect estimate.
      • Ungraded means a grade is not assignable.
    • Search Plan and Results: Sucrose Intake 2007