Background – In Australia, the concept of the Glycemic Index (GI) was introduced to the general public through dietitians, other health professionals and the popular press in the mid 1990s, with the recommendation to consume more low-GI foods.
Objective – To determine whether general advice to consume more low GI foods has impacted the mean dietary GI of a representative sample of older Australians over the last 10 years.
Design – Prospective cohort study of 3,654 people aged 49 years or older in the Blue Mountains region of NSW. A total of 2,868 people completed a 145-item semi-quantitative food frequency questionnaire satisfactorily in 1992-94 (BMES 1), and were followed up in 1997-1999 (BMES 2), and 2002-4 (BMES 3). This data analysis includes those people who satisfactorily completed the FFQ on all three occasions (n=1166). Nutrient intake data were analysed in a custom-built database using the NUTTAB (1-2) databases and Australian GI values (3). One-way analysis of variance was used to determine differences between mean dietary GI.
Outcomes – Mean dietary GI was 56.5±4.2 in BMES 1, 56.4±4.3 in BMES 2 and 56.2±4.3 in BMES 3 (P=0.037). Post-hoc comparisons using the Tukey HSD test indicated that mean dietary GI for BMES 3 was significantly lower than BMES 1, but BMES 2 did not differ significantly from either BMES 1 or 3.
Conclusion – Mean dietary GI values of older Australians have dropped by a small but significant amount since the mid 1990’s. Recommendations to consume more low-GI foods may be having a positive effect on older Australians’ diets.
References
1 Department of Community Services and Health. NUTTAB 90 Nutrient Data Table for Use in Australia. Canberra: Australian Government Publishing Service, 1990.
2 Department of Community Services and Health. NUTTAB 95 Nutrient Data Table for Use in Australia. Canberra: Australian Government Publishing Service, 1995.
3 Foster-Powell K, Holt SH, & Brand-Miller JC. International table of glycemic index and glycemic load values: 2002. Am J Clin Nutr 2002; 76: 5-56.