The bodies of evidence examining the relationship between dietary patterns and risk of type 2 diabetes were limited or insufficient, but they generally supported consumption of a dietary pattern rich in fruits and vegetables and low in high-fat dairy and meats.
Conclusion Statements: Dietary Patterns and Risk of Type 2 Diabetes
Limited or Insufficient Evidence:
There 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 high-fat dairy, assessed using an index or score, is associated with decreased risk of type 2 diabetes.
(Grade: III - Limited) (Index Analysis)
Limited and inconsistent evidence from epidemiological studies indicates that in adults, dietary patterns derived using factor or cluster analysis, characterized by vegetables, fruits, and low-fat dairy products tend to have an association with decreased risk of type 2 diabetes and those patterns characterized by red meat and sugarsweetened foods and drinks, French fries, refined grains, and high-fat dairy products tended to show an increased association for risk of type 2 diabetes. Among studies, there was substantial variation in food group components and not all studies with similar patterns showed significant association.
(Grade: III - Limited) (Factor or Cluster Analysis)
There is insufficient evidence on a relationship between adherence to a Mediterranean-style or vegetarian diet pattern and incidence of type 2 diabetes. There is limited, inconsistent evidence that adherence to a Mediterranean-style, DASH or modified DASH, or Nordic dietary pattern results in improved glucose tolerance and insulin resistance.
(Grade: IV - Not Assignable - Incidence of type 2 diabetes; Grade: III – Limited - Glucose tolerance and insulin resistance) (Other Methods)
There is insufficient evidence, due to a small number of studies, to examine the relationship between dietary patterns derived using reduced rank regression and risk of type 2 diabetes. The differences in the methods used and populations studied made it difficult to compare results, and therefore no conclusions were drawn.
(Grade: IV - Not Assignable) (Reduced Rank Regression)