The association between carbohydrate quality and nutrient adequacy in Australian adults

To examine the association between various carbohydrate quality indicators and nutrient adequacy in Australian adults.

Dietary data from adult participants of the 2011-2012 Australian Health Survey (weighted n = 6150) who had completed two 24 h recalls were analyzed. Glycaemic indices (GI) of foods were estimated based on a published method. Quartiles of dietary GI (dGI) and glycaemic load (dGL), and intakes of high (CHO_highGI) and low-GI carbohydrates (CHO_lowGI) were derived. Estimated marginal means and standard errors of nutrient and food group intakes by quartiles were calculated using ANCOVA. Odds ratios of not meeting the nutrient reference values for Australia and New Zealand (NRVs) by quartiles of the carbohydrate quality indicators were calculated by logistic regression. Analyses were adjusted for known confounders.

Participants with higher CHO_highGI had lower intakes of the majority of nutrients examined, except sodium and %energy from free sugars. They were also more than 100% more likely to not meet the NRVs of vitamin A (2.19, 95% CI 1.89, 2.84), vitamin C (3.93, 95% CI: 1.61, 9.60), vitamin E (2.63, 95% CI: 2.08, 3.31), iron (2.27, 95% CI: 1.48, 3.49), magnesium (2.50, 95% CI: 2.01, 3.12), potassium (2.25, 95% CI: 1.79, 2.83), %EFS (2.74, 95% CI: 2.22, 3.38), and LCn3PUFA (2.35, 95% CI: 1.76, 3.16). Similar results were observed for dGI and dGL, while trends for CHO_lowGI were in opposite direction in general.

Of the carbohydrate quality indicators examined, CHO_highGI was the strongest predictor of nutrient adequacy. Improvement in nutrient adequacy likely contributed to the health protective effect of a low-GI diet.