Mediterranean Diet and Global Dietary Shifts, 1990–2018: Population-Level Analysis Using Global Dietary Database

Background: The Mediterranean diet (MD) has well-established health benefits, yet modern food systems are driving a nutrition transition. Quantifying how Mediterranean countries have shifted relative to global trends is essential for evidence-based public health. Aim: Dietary changes between 1990 and 2018 were examined in Mediterranean coastline countries (MED) in comparison with high-income non-Mediterranean countries (HIC non-MED) and middle-/low-income non-Mediterranean countries (MLIC non-MED). Methods: Using the Global Dietary Database, within-country changes (1990 vs. 2018) for 13 food categories were analysed across 185 nations in three groups: MED countries (n = 21), HIC non-MED (n = 18), and MLIC non-MED (n = 146). MED countries were further grouped into Southern Europe (SE), Western Asia (WA), and North Africa (NA). Paired unweighted country-level analyses were the primary analyses; population-weighted analyses were sensitivity checks. Benjamini–Hochberg’s false-discovery-rate correction and centred log-ratio compositional analysis were applied. Results: MED seafood intake rose from 20.5 to 33.8 g/day (Δ = +13.3 g/day; 95% CI: +6.2 to +18.4; q = 0.003), and non-starchy vegetables increased from 135.5 to 173.6 g/day (Δ = +38.0 g/day; q = 0.626). Refined/starchy carbohydrate intake rose by 63.3 g/day in MED countries while declining by 33.6 g/day in HIC non-MED countries (between-group divergence +96.9 g/day; q = 0.006). Nuts and seeds rose across all groups; legumes declined modestly in MED countries. Saturated fatty acids + omega-6 polyunsaturated fatty acids (% kcal) rose by +0.6 percentage points in MED countries but fell in HIC non-MED countries. Monounsaturated fatty acids were stable. MED-WA showed the greatest overall divergence from the SE 1990 pattern. Conclusions: These findings highlight a public health paradox: the MD is globally promoted as a model of healthy eating, yet adherence within its region of origin is declining. Targeted, region-specific strategies are urgently needed to preserve beneficial MD elements while addressing emerging diet-related risks.