Mediterranean Dietary Transition and a Weighted Food-Related Carbon-Pressure Proxy in Portugal: Evidence from Dynamic Time-Series Analysis

Using Portuguese Food Balance Sheet data for 1990–2024, this study examines whether Mediterranean-classified food availability is associated with an annualised per-capita weighted food-related carbon-pressure proxy (WFCPP). A dynamic HAC–Newey–West model (1998–2024; 27 observations) separates dietary composition from analytical total caloric availability through orthogonalisation, while an exploratory ARDL–UECM assesses conditional level relationships. Because the WFCPP, Mediterranean dietary component, and caloric-availability control share food-group series, orthogonalisation reparameterises rather than removes their structural dependence. The baseline Mediterranean coefficient is negative (β = −0.467; p = 0.018) but becomes insignificant under HC3 inference, exclusion of 2012–2013, the Mediterranean Adequacy Index, and the per-calorie WFCPI; all block-bootstrap 95% intervals contain zero. In the selected ARDL, Mediterranean coefficients are insignificant in both the short and long run. Accordingly, H1 is not robustly supported, and H2 is unsupported; no robust Mediterranean-specific negative association is confirmed at either horizon. The analysis concerns apparent food availability and fixed dimensionless weights, not actual consumption, causal effects, or physical greenhouse-gas emissions.