Citation:
Hu FB, van Dam RM, Liu S. Diet and risk of Type II diabetes: The role of types of fat and carbohydrate. Diabetologia. 2001 Jul; 44(7): 805-817.
PubMed ID: 11508264
Study Design:
Meta-analysis or Systematic Review
Class:
M -
Click here for explanation of classification scheme.
Research Design and Implementation Rating:
POSITIVE: See Research Design and Implementation Criteria Checklist below.
Research Purpose:
To review current evidence on the association between types of fat and carbohydrates and insulin resistance and type 2 diabetes (T2D).
Inclusion Criteria:
- Epidemiologic studies that examine the associations between dietary fat and carbohydrate and risk of developing hyperglycemia and T2D
- Included both prospective cohort studies and cross-sectional studies
- Examined specific fatty acids
- Subjects without T2D or impaired glucose tolerance (IGT).
Exclusion Criteria:
- Human diet intervention trials
- Did not examine specific fatty acids
- Subjects with T2D or IGT
- Animal studies.
Description of Study Protocol:
Recruitment
14 epidemiologic studies and five cross-sectional studies of dietary fat and carbohydrate and association with hyperglycemia and T2D.
Design
Systematic review.
Dietary Intake/Dietary Assessment Methodology
Food-frequency questionnaires (FFQs) and diet history.
Data Collection Summary:
Date Range
1974 to 2001.
Dependent Variables
Type 2 diabetes.
Independent Variables
Types of dietary fatty acids and carbohydrates.
Description of Actual Data Sample:
- Initial N: 20 to 4,903
- Age: Adults (age range 25 to 89 years)
- Ethnicity: International
- Other relevant demographics: Observational studies conducted on men and women in specific sub-populations in the US, Europe and Israel
- Location: US, Europe, Israel.
Summary of Results:
Key Findings
- Higher intakes of polyunsaturated fatty acids (PUFA) could improve glucose metabolism and insulin resistance
- Long-chain PUFA may also improve glucose metabolism and insulin resistance
- Higher intakes of saturated fatty acids (SFA) adversely affect glucose metabolism and insulin resistance
- High intakes of vegetable fat and PUFA were associated with a decreased risk of T2D.
Author Conclusion:
Replacing SFA with PUFA could appreciably reduce risk of type 2 diabetes.
Reviewer Comments:
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Research Design and Implementation Criteria Checklist: Review Articles
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Relevance Questions
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1.
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Will the answer if true, have a direct bearing on the health of patients? |
Yes
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2.
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Is the outcome or topic something that patients/clients/population groups would care about? |
Yes
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3.
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Is the problem addressed in the review one that is relevant to nutrition or dietetics practice? |
Yes
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4.
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Will the information, if true, require a change in practice? |
Yes
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Validity Questions
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1.
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Was the question for the review clearly focused and appropriate? |
Yes
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2.
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Was the search strategy used to locate relevant studies comprehensive? Were the databases searched and the search termsused described? |
Yes
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3.
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Were explicit methods used to select studies to include in the review? Were inclusion/exclusion criteria specified and appropriate? Were selection methods unbiased? |
Yes
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4.
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Was there an appraisal of the quality and validity of studies included in the review? Were appraisal methods specified, appropriate, and reproducible? |
???
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5.
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Were specific treatments/interventions/exposures described? Were treatments similar enough to be combined? |
Yes
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6.
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Was the outcome of interest clearly indicated? Were other potential harms and benefits considered? |
Yes
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7.
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Were processes for data abstraction, synthesis, and analysis described? Were they applied consistently across studies and groups? Was there appropriate use of qualitative and/or quantitative synthesis? Was variation in findings among studies analyzed? Were heterogeneity issued considered? If data from studies were aggregated for meta-analysis, was the procedure described? |
Yes
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8.
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Are the results clearly presented in narrative and/or quantitative terms? If summary statistics are used, are levels of significance and/or confidence intervals included? |
Yes
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9.
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Are conclusions supported by results with biases and limitations taken into consideration? Are limitations of the review identified and discussed? |
Yes
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10.
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Was bias due to the review’s funding or sponsorship unlikely? |
Yes
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