Understanding sustainable dietary transitions in Portugal: The role of individual and territorial drivers

This study examines how individual behavioural factors interact with territorial food environments to shape the adoption of sustainable dietary practices in mainland Portugal. Combining the Socio-Ecological Model with the Capability–Opportunity–Motivation behavioural framework, we propose a Multilevel Sustainable Dietary Change Model and apply a two-step methodological strategy. First, 23 Portuguese regions were classified into food-environment typologies using 17 multidimensional indicators spanning socio-demographic, economic, land-use, food-access, and agri-environmental conditions. Four distinct territorial types emerged: rural, semi-urban, multicultural/economic-specialized, and urban. Second, these clusters were integrated into a binary logistic regression using survey data (N = 1,170) to assess how behavioural determinants operate across different territorial contexts. The national model showed good predictive performance (area under the curve = 0.748). Higher education (odds ratio = 1.39), awareness of climate change (odds ratio = 2.74), belief in public-sector responsibility (odds ratio = 1.53), and positive dietary self-perception (odds ratio = 1.36) increased the likelihood of adopting more sustainable dietary practices, whereas limited knowledge (odds ratio = 0.84) and concerns about nutritional adequacy (odds ratio = 0.80) reduced it. Cluster-specific models revealed substantial territorial heterogeneity: urban environments offer more favourable conditions for change, affordability constraints are particularly strong in multicultural and economically specialised regions (odds ratio = 0.39), and rural areas are affected by reduced access to food outlets (odds ratio = 0.63). Overall, the findings demonstrate that sustainable dietary change emerges from the interaction between individual motivations and capabilities and the structural opportunities embedded in food environments. This highlights the need for system-oriented food policies that address both individual behaviours and territorial specificities.