Estimates of the Dietary Glycemic Index and Load in a Representative Sample of the Greek Population

Introduction: The dietary glycemic index (GI) and glycemic load (GL) are dietary indicators of how carbohydrate-containing foods affect blood glucose. While the Mediterranean diet’s glycemic impact has been explored, data specific to the Greek population remain limited. This study aims to assess the dietary GI and GL in the HYDRIA survey of a representative sample of Greek adults. Methods: HYDRIA was conducted from June 2013 to December 2014 and collected nationally representative data, including detailed dietary information. GI and GL were analyzed by age, sex, BMI, education, employment, smoking status, and Mediterranean diet adherence. Multivariate analysis was used to identify independent predictors of GI and GL. Results: The analysis included 3951 adults (52% females; median age: 49 years). The average GI was 59.7 (95% CI: 59.4–60.0) and the mean GL 101.7 (95% CI: 99.4–104.0). Males had significantly (p ≤ 0.001) higher mean GI and GL (61.2, 95% CI: 57.4–64.7 and 112.9, 95% CI: 82.1–151.1, respectively) than females (59.2, 95% CI: 55.6–62.8 and 81.9, 95% CI: 62.2–107.8, respectively). Older age (≥55 years) and higher education were associated with lower GI and GL in both sexes. Current smoking was associated with higher GI and GL, particularly in males. Among males, medium and high adherence to the Mediterranean diet was associated with lower GI and GL. This relationship was not observed in females. Discussion: These findings emphasize the role of demographics and lifestyle factors in determining differences in dietary GI and GL of the Greek population. The Mediterranean diet appeared to mitigate the dietary GI and GL mainly in males, suggesting effects that merit further investigation.