(P07-009-20) Cardiometabolic Health-Promoting Effects of Low- and High-Glycemic Mediterranean-Style Eating Patterns: The MedGI-Carb Randomized Controlled Trial

Objectives: A Mediterranean-style healthy eating pattern (MED-HEP) and consumption of foods with a lower glycemic index (GI) are potential dietary approaches to reduce the incidence of type 2 diabetes and cardiovascular disease. However, experimental evidence for the effectiveness of MED-HEP and firm evidence of the contribution of GI towards improving indices of cardiometabolic health are lacking. Therefore, the purpose of this study was to assess the effects of MED-HEPs differing in GI on cardiometabolic health indices.

Methods: Fifty-four subjects (33 F, 21 M; age 49 ± 11 y; BMI: 31.3 ± 3.1) completed the randomized, controlled MedGI-Carb Trial. All participants were randomized to consume either an energy-sufficient, isocaloric Low-GI or High-GI MED-HEP, differing only in the GI of half the carbohydrate-foods (CHO), for 12 weeks. Both groups consumed 270 g/d of metabolizable CHO; 135 g of CHO in the Low-GI group came from foods with GI values < 55, while 135 g of CHO in the High-GI group came from foods with GI values > 70. All foods were provided to participants and consumed as part of a 7-day rotating menu. Higher or lower energy content was achieved through modulation of dietary fat and protein in the menus. Fasting plasma glucose, HbA1c, total cholesterol, triglycerides, HDL, LDL, systolic blood pressure (BP), and diastolic BP were assessed before and after the 12-week dietary intervention. Significance level was set at p< 0.05 (denoted by *).

Results: Apart from HbA_1c, there were no between-group differences. Consumption of the High-GI MED-HEP resulted in a decrease in HbA_1c* (-0.1 ± 0.03%, mean ± SD), while there was no change in the Low-GI group (0.0 ± 0.03%). In both groups, fasting glucose (1 ± 1 mg/dL) and triglycerides (-11 ± 10 mg/dL) remained unchanged after the intervention. Total cholesterol* (-12 ± 2 mg/dL), HDL* (-3 ± 1 mg/dL), LDL* (-5 ± 2 mg/dL), systolic BP* (-7 ± 1 mm Hg), and diastolic BP* (-5 ± 1 mm Hg) all decreased during the intervention, with no difference between the High- and Low-GI groups.

Conclusions: Mediterranean-style HEPs are effective in improving indices of cardiovascular health, with largely no differences in the magnitude of improvement between High- and Low-GI groups.

Funding Sources: Barilla International, Barilla USA