Nutrition Counseling

NC: CBT Duration and Health/Food Behavior Change (2007-2008)

• Intervention
  What is the evidence that cognitive-behavioral therapy (CBT), of short, intermediate or long duration targeted to reduce cardiovascular disease and diabetes risk factors, diabetes management and/or weight loss, results in health/food behavior change in adults counseled in an out patient/clinic setting?

  • Conclusion

    Overall

    18 positive-quality RCTs, five neutral-quality RCTs, two neutral-quality non-randomized trial and two neutral-quality quasi-experimental studies provide evidence that cognitive behavioral therapy (CBT) is beneficial in facilitating modification of targeted dietary habits (e.g., decreased calories from fat, decreased sodium, increased intake of fruits and vegetables), weight and cardiovascular and diabetes risk factors. Evidence is particularly strong in patients with type 2 diabetes receiving intensive, intermediate-duration CBT (six to 12 months in duration) and long-term (more than 12 months duration) CBT targeting prevention or delay in onset of type 2 diabetes, hypertension and other cardiovascular disease risk factors. 

    Short-Term CBT (Less than six month treatment phase)

    Four positive-quality RCTs, one neutral-quality RCT and one neutral-quality non-randomized trial provide evidence that short-term CBT results in positive lifestyle change, yielding a reduction in weight, lipid levels, fat intake and improved glucose control.

    Intermediate Length CBT (6-12 treatment phase)

    Five positive-quality RCTs, three neutral-quality RCTs and two neutral-quality, quasi-experimental non-randomized trials provide evidence that intermediate length CBT, compared to standard treatment results in significant improvements in weight management, cardiovascular risk factors and type 2 diabetes. Evidence is strongest among patients with type 2 diabetes, due to the number, size and quality of studies.

    Long-Term CBT (Greater than 12 month treatment phase)

    Nine positive-quality RCTs, one neutral-quality RCT, one neutral-quality non-randomized trial and one neutral-quality quasi-experimental study provide evidence that long-term CBT  (greater than 12-months), facilitates positive lifestyle change, which may result in significant reductions in weight, lipid levels, blood pressure and incidence of hypertension. Interventions targeting prevention of type 2 diabetes were highly successful, but those targeting diabetes management indicated difficulty sustaining most outcomes over the long-term.

  • 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.