Associations of the Mediterranean diet during pregnancy with impaired glucose tolerance and gestational diabetes: A national prospective cohort study in Lebanon

Abstract Background/objectives This study assessed whether adherence to the Lebanese Mediterranean diet (LMeD) is associated with a lower risk of gestational diabetes mellitus (GDM) and impaired glucose tolerance (IGT) among a national sample of pregnant women in Lebanon. Methods For this longitudinal study, 618 women were recruited in trimester 1. The main outcomes were IGT and GDM. Independent variables included adherence to the LMeD, maternal anthropometry, clinical and biochemical variables collected at 3 trimesters. Hierarchical multiple logistic regression was used to test associations of independent predictors with IGT and GDM. Results The diagnosis of GDM was 5.6%, whereas IGT was more prevalent, and increased from 17% to 24% from T1 to T3, but neither GDM nor IGT risk was associated with adherence to LMeD. A higher consumption of legumes and burghol increased IGT risk in trimester 1 whereas vegetables lowered IGT risk in trimester 3. Family history of diabetes, high gestational weight gain (GWG) and elevated Mean Arterial Pressure (eMAP) were associated with increased GDM risk. Conclusion Findings underscore the importance of early screening for family history of diabetes, excessive gestational weight gain (GWG), stress, and elevated mean arterial pressure (MAP) to target to identify women at risk of IGT and GDM. Trimester-specific dietary strategies, such as reducing overconsumption of burghul and legumes in early pregnancy and promoting vegetable intake later, may help improve maternal glycemia.