The link between dietary glycemic index and nutrient adequacy

Background: Low-glycemic index (low-GI) diets may be less nutritious because of limited food choices. Alternately, high-GI diets could be less healthful because of a higher intake of refined carbohydrate. Objective: The objective was to investigate the association between dietary GI, intakes of carbohydrates from high-GI (CHOhigh GI) and low-GI (CHOlow GI) sources, and the risk of nutrient inadequacy in children and adolescents. Design: Children, aged 2-16 y, who provided 2 plausible 24-h recalls in a national survey were included (n = 4140). The ORs of not meeting the Australian Nutrient Reference Values (NRVs) were calculated by logistic regression. Results: Subjects with higher intakes of CHOhigh GI were found to be at risk of not meeting the NRVs for a wide range of nutrients, including calcium and iodine (both P-trend < 0.001). In comparison with subjects in the lowest quartile of CHOhigh GI, those in the highest quartile had 3 times (adjusted OR: 3.13; 95% CI: 2.47, 3.97; P-trend < 0.001) the risk of not meeting the Estimated Average Requirement for calcium. For iodine, the risk increased >5-fold (adjusted OR: 5.45; 95% CI: 3.97, 7.48; P-trend < 0.001). On the other hand, subjects with higher intakes of CHOlow GI were less likely to meet Adequate Intakes of unsaturated fatty acids (all Ptrend < 0.001), despite having lower risks of not meeting the NRVs for most nutrients. Conclusion: Children and adolescents who consume more CHOlow GI are more likely to meet most nutrient recommendations than those consuming higher GI diets. Am J Clin Nutr 2012;95:694-702.