Table 4.

Questions asked and the conclusions of the systematic literature reviews for the dietary guidelines for Americans 2010 regarding the GI

Question	Conclusion	Number of studies
What is the relationship between glycemic index or glycemic load and body weight?	‘Strong and consistent evidence shows that glycemic index and/or glycemic load are not associated with body weight and do not lead to greater weight loss or better weight maintenance.’	Based on 22 studies, 13 randomized TC, 2 prospective, 7 cross sectional.
What is the relationship between glycemic index or glycemic load and type 2 diabetes?	‘A moderate body of inconsistent evidence supports a relationship between high glycemic index and type 2 diabetes.’ ‘Strong, convincing evidence shows little association between glycemic load and type 2 diabetes.’	Based on 10 prospective studies. Based on 10 prospective studies.
What is the relationship between glycemic index or glycemic load and cardiovascular disease?	‘Due to limited evidence, no conclusion can be drawn to assess the relationship between either glycemic index or load and cardiovascular disease.’	Based on 8 studies.
What is the relationship between glycemic index or glycemic load and cancer?	‘Abundant, strong epidemiological evidence demonstrates that there is no association between glycemic index or load and cancer.’	Based on 20 prospective longitudinal studies, 2 case cohort and 5 case control studies.

A description of the Nutrition Evidence Library (NEL) evidence-based systematic review process (a web-based state of the art electronic system) can be found in Part C of the report (http://www.cnpp.usda.gov/Publications/DietaryGuidelines/2010/DGAC/Report/C-Methodology.pdf). It was used to address the majority of the science based research questions posed by the Committee. Additional information about the NEL search strategies and criteria used to review each question can be found online at: www.nutritionevidencelibrary.com