What is the relationship between adherence to dietary guidelines/recommendations or specific dietary patterns, assessed using an index or score, and risk of type 2 diabetes?
ConclusionThere is limited evidence that adherence to a dietary pattern rich in fruits, vegetables, legumes, cereals/whole grains, nuts, fish, and unsaturated oils, and low in meat and red meat and high-fat dairy, assessed using an index or score, is associated with decreased risk of type 2 diabetes.
GradeIII – Limited
- Among included studies there was variation in the types of indices or scores used, without a preponderance of studies with any one index related to either risk of type 2 diabetes or fasting blood glucose and insulin resistance, making it difficult to draw overarching conclusions related to a specific dietary pattern.
- The different scores showed varied predictability of incident type 2 diabetes:
- In European populations, adherence to the MDS was associated with reduced incidence of type 2 diabetes. Additionally, among women in a U.S. cohort, the AHEI had similar relationships.
- For other scores considered, such as the Total Diet Score, German Food Pyramid Index, DQI-2005, as well as the MDS in a U.S. population, there was no relationship between diet quality and incidence of type 2 diabetes.
- One study assessing the DASH score in a U.S. population showed an association in Whites but not in Blacks. A second study showed no association between DQI-2005 and T2D incidence in Black or White young adults.
- The different scores showed varied association with glucose tolerance and/or insulin resistance:
- For impaired fasting glucose or insulin resistance, there was some agreement with the MDS and MSDPS being protective for the measures examined.
- There were mixed findings for Total Diet Score, DQI-2005, and an authors’ a priori score. For the mixed results, the findings differed by sex, type of intermediate outcome examined, and race/ethnicity.
What is the evidence that supports this conclusion? For more information, click on the Evidence Summary link below.
Overall, there is a need for more coordinated studies involving multiple U.S. cohorts, all of which examine the same scores or indices assessed in a standardized way. In addition, more analysis of key subpopulation groups, with sufficient sample sizes, would further inform policy in this area.
Search Plan and Results
What were the search parameters and selection criteria used to identify literature to answer this question? For more information, click on the Search Plan and Results link below.