An Integrated Conceptual Framework for the Sustainable Adoption of the Mediterranean Diet: The Mediating Role of Plant-Based Foods

Abstract

Sustainable dietary transitions are increasingly recognised as essential for addressing the interconnected challenges of public health, environmental degradation and food system sustainability. Although the Mediterranean Diet (MD) is widely acknowledged as a healthy and sustainable dietary model, adherence has progressively declined across diverse populations. This study develops an integrated conceptual framework to explain the sustainable adoption of the Mediterranean Diet, with particular emphasis on the conceptual mediating role of plant-based foods. A structured conceptual narrative review was conducted using interdisciplinary evidence from nutrition science, sustainability research, behavioural sciences and food policy. The proposed framework integrates individual capacities, socio-cultural contexts, structural environments and ecological awareness within a systems-oriented perspective. The findings suggest that dietary behaviour is shaped by dynamic and context-dependent interactions influenced by feedback mechanisms, life-course transitions and structural constraints. Within this framework, plant-based foods function as integrative leverage points linking health, environmental and cultural dimensions. The study highlights the limitations of individual-centred approaches and emphasises the importance of coordinated multi-level strategies to support sustainable dietary transitions. Overall, the framework provides a theoretically grounded basis for future research, policy development and integrated interventions aimed at promoting resilient and sustainable food systems.

1. Introduction

The global food systems are currently facing complex and interconnected challenges driven by the simultaneous rise in non-communicable diseases, environmental degradation and persistent social inequalities, which collectively threaten both human and planetary health [1,2,3]. Contemporary dietary patterns, characterised by high consumption of ultra-processed foods and animal-based products, contribute significantly to greenhouse gas emissions, excessive natural resource use and the global burden of chronic diseases [4,5,6,7]. In response, the transition towards sustainable dietary patterns has become a central priority within public health, environmental policy and food system governance [2,8].

The Mediterranean Diet (MD) is widely recognised as a robust and evidence-based dietary model for promoting both human health and environmental sustainability [9]. A substantial body of evidence associates adherence to the MD with reduced risk of cardiometabolic diseases, increased longevity and improved overall well-being across diverse populations [10,11]. Characterised by a high intake of plant-based foods, including fruits, vegetables, legumes, whole grains, nuts and olive oil, alongside moderate consumption of fish and dairy products and low intake of red and processed meat, the MD represents a predominantly plant-centred dietary pattern with well-established health benefits [12,13]. In addition, growing evidence indicates that the MD is generally associated with lower environmental impacts compared with Western dietary patterns, particularly in terms of greenhouse gas emissions, land use and resource consumption [14,15,16].

Recent conceptual developments, such as the Med Diet 4.0 framework, have expanded the understanding of the MD beyond a purely nutritional model by integrating health, environmental, socio-cultural and economic dimensions within a unified perspective [17]. This multidimensional framing positions the MD as a reference model for sustainable food systems. However, despite its recognised benefits, adherence to the MD has declined in both Mediterranean and non-Mediterranean countries, largely driven by urbanisation, globalisation of food markets, changing lifestyles and socio-economic constraints [18,19,20].

In parallel, plant-based foods have gained increasing attention as key components of sustainable diets and food system transformation strategies [21]. Dietary patterns rich in plant-based foods are consistently associated with improved health outcomes and reduced environmental footprints, particularly through lower greenhouse gas emissions and reduced resource intensity [6,7,22,23]. Within Mediterranean food cultures, plant-based foods have historically constituted the nutritional and cultural foundation of traditional dietary practices, reflecting long-standing interactions between ecological conditions and socio-cultural traditions [24]. Nevertheless, their role in enabling sustainable adoption of dietary patterns remains insufficiently explored within integrated conceptual frameworks that account for behavioural, social and structural determinants [25].

Existing research on the MD has predominantly focused on clinical outcomes, nutritional adequacy or isolated environmental indicators, providing valuable but partial insights into its broader implications [26]. These approaches often overlook the complex interactions between individual behaviours, socio-cultural norms, structural conditions and environmental awareness that shape dietary practices in real-world contexts [27,28]. The limited availability of integrative and systems-based conceptual models constrains the development of effective, scalable and context-sensitive interventions aimed at promoting long-term dietary change [29].

To address this gap, the present study proposes an integrated conceptual framework to explain the sustainable adoption of the Mediterranean Diet, with particular emphasis on the role of plant-based foods as mediating components within dietary systems. Drawing on interdisciplinary evidence from nutrition science, sustainability research, behavioural sciences and food policy, the framework adopts a systems-oriented perspective that captures the dynamic interactions between individual, socio-cultural, structural and ecological determinants of dietary behaviour [28]. This framework contributes to a more sophisticated and context-sensitive grasp of sustainable food transitions, underpinning the design of integrated research goals, strategic policies, and actionable interventions for varied socio-economic landscapes [8].

In the present framework, the mediating role of plant-based foods is conceptual rather than statistical. Plant-based foods are viewed as integrative elements that connect health, environmental, socio-cultural and food-system dimensions, thereby facilitating the sustainable adoption of Mediterranean dietary patterns.

2. Methodology

2.1. Study Design

This study adopts a structured conceptual narrative review to synthesise interdisciplinary evidence regarding the sustainable adoption of the Mediterranean Diet, with particular emphasis on plant-based dietary practices. A narrative and concept-oriented approach was considered the most appropriate due to the multidisciplinary, complex and evolving nature of the topic, which intersects nutrition science, sustainability research, behavioural sciences, public health and food policy [30,31]. Rather than aiming to provide an exhaustive quantitative synthesis of the literature, the review seeks to develop a theoretically grounded and integrative understanding of the determinants, mechanisms and systemic interactions shaping sustainable dietary behaviours. The study further aims to propose a conceptual framework capable of reflecting the complexity, interdependence and context sensitivity of contemporary food systems.

2.2. Search Strategy and Data Sources

A structured literature search was conducted between December 2025 and February 2026 across major academic databases, including PubMed, Scopus, Web of Science and Google Scholar, to identify relevant peer-reviewed publications. To ensure a broader and interdisciplinary perspective, the search was complemented by the inclusion of grey literature, including reports and policy documents from international organisations such as the Food and Agriculture Organization (FAO), the World Health Organization (WHO) and the High Level Panel of Experts on Food Security and Nutrition (HLPE).

Search terms were developed iteratively and combined using Boolean operators (AND, OR). The search strategy included combinations of terms such as “Mediterranean Diet”, “plant-based diet”, “sustainable diet”, “dietary behaviour”, “food systems”, “food environment”, “nutrition transition” and “sustainability”. Example search strings included (“Mediterranean Diet” AND sustainability AND “plant-based”), (“Mediterranean Diet” AND “food systems”), and (“dietary behaviour” AND sustainability AND “plant-based diet”). No strict restrictions were applied regarding publication date; however, priority was given to literature published between 2010 and 2026, with particular emphasis on recent developments related to sustainable diets, plant-based food systems and food system transformation. Supplementary Table S1 provides details regarding databases, search terms, eligibility criteria and study selection procedures.

2.3. Eligibility Criteria and Study Selection

The selection of studies was conducted in two stages. Initially, titles and abstracts were screened to assess conceptual relevance and alignment with the objectives of the review. Subsequently, full-text assessment was performed based on predefined inclusion and exclusion criteria.

Studies were included if they (i) addressed determinants of dietary behaviour within sustainability frameworks; (ii) examined Mediterranean dietary patterns and/or plant-based diets; (iii) explored structural, socio-cultural, environmental or behavioural influences on food choices; and/or (iv) contributed conceptually or empirically to the understanding of sustainable food systems and dietary transitions.

Studies were excluded if they (i) focused exclusively on clinical or biomedical outcomes without broader behavioural, social or systemic context; (ii) did not address sustainability or food system dimensions; or (iii) lacked conceptual or analytical relevance to the objectives of the present review.

The study selection process was iterative and flexible, allowing additional relevant sources to be identified through reference screening and snowball sampling, particularly in relation to conceptual, policy-oriented and interdisciplinary literature. Following the screening and eligibility assessment stages, 104 sources met the inclusion criteria and were incorporated into the final conceptual synthesis.

2.4. Analytical Approach

A thematic and conceptual analysis was conducted to synthesise the selected literature and identify the principal dimensions shaping sustainable dietary adoption. The analytical process involved iterative coding, categorisation and integration of key themes related to (i) individual determinants, including knowledge, motivation, food literacy and self-efficacy; (ii) socio-cultural influences, including norms, traditions, identity and social practices; (iii) structural conditions, including food environments, affordability, accessibility and policy frameworks; and (iv) ecological and sustainability-related factors, including environmental awareness, climate concerns and perceived environmental responsibility.

These themes were progressively integrated to identify patterns, interdependencies and interaction mechanisms across domains. Particular attention was given to the non-linear, adaptive and context-dependent nature of dietary behaviour within complex food systems. The conceptual framework proposed in this study emerged from this integrative synthesis, reflecting both the convergence of interdisciplinary evidence and the identification of key leverage points for sustainable dietary transitions.

2.5. Methodological Considerations

Given the conceptual and narrative nature of this review, the literature identification and synthesis process was iterative rather than strictly linear and did not follow a formal systematic review protocol such as PRISMA [32]. Consequently, the objective was not to provide an exhaustive inventory of all available studies, but rather to identify representative, high-quality and conceptually relevant evidence capable of supporting the development of an integrated theoretical framework.

Although efforts were made to ensure methodological transparency, analytical rigor and interdisciplinary breadth, the findings should be interpreted as a conceptual synthesis rather than as a quantitative or statistically generalisable assessment of the literature. In addition, the proposed framework is intended to function as a systems-oriented and theoretically informed model, with the mediating role of plant-based foods interpreted conceptually rather than statistically.

3. Mediterranean Diet and Sustainability

The MD is widely recognised as one of the most comprehensive dietary patterns for promoting both human health and environmental sustainability within contemporary food systems [3,9,17]. Originally described in the mid-twentieth century based on traditional dietary practices in Southern European populations, the MD reflects a balanced integration of nutritional adequacy, cultural heritage and ecological adaptation [12,24].

From a nutritional perspective, the MD is characterised by a high intake of fruits, vegetables, legumes, whole grains, nuts and olive oil, alongside moderate consumption of fish, dairy products and poultry, and limited intake of red and processed meat [17]. This composition provides substantial amounts of dietary fibre, unsaturated fatty acids, micronutrients and bioactive compounds, which have been consistently associated with reduced risk of cardiovascular disease, type 2 diabetes, obesity and certain cancers [11,33,34].

Beyond its established health benefits, increasing attention has been directed towards the environmental performance of the MD within sustainability frameworks [3,17]. Life cycle assessment studies indicate that Mediterranean-aligned dietary patterns generally generate lower greenhouse gas emissions, require fewer natural resources and exert reduced pressure on biodiversity compared with Westernised diets [6,7,35]. These advantages are largely driven by the predominance of plant-based foods and the lower reliance on resource-intensive animal products [4,6].

Recent empirical evidence further supports the relevance of the MD within sustainability-oriented dietary transitions, showing that higher adherence is associated with healthier food choices and more sustainable consumption behaviours across diverse populations [36,37,38]. Comparative analyses also suggest that the MD provides a favourable balance between environmental, economic and health outcomes when contrasted with alternative dietary scenarios, although results vary depending on methodological assumptions and contextual factors [39,40,41]. Nevertheless, adherence levels remain suboptimal, reflecting a persistent gap between dietary recommendations and real-world practices [36,42].

Contemporary frameworks, such as Med Diet 4.0, have expanded the conceptualisation of the MD by integrating health, environmental, socio-cultural and economic dimensions within a unified perspective [17,43]. This multidimensional approach positions the MD as a reference model for sustainable food systems rather than a purely nutritional guideline [37,43].

However, a significant proportion of the literature relies on aggregated indicators and modelled scenarios that may not fully capture real-world complexity [26]. These approaches often overlook socio-economic inequalities, regional food system constraints and variations in food affordability, which critically shape dietary practices [44,45]. As a result, the sustainability potential of the MD may be overestimated when structural barriers and market dynamics are insufficiently considered [46].

Despite its recognised potential, adherence to the MD has declined substantially in recent decades due to urbanisation, globalisation of food markets, time constraints and changes in household structures [47,48]. This nutritional transition has been accompanied by increased consumption of ultra-processed foods and animal-based products, contributing to both declining diet quality and increased environmental pressures [5,20].

Importantly, the sustainability of the MD cannot be understood solely through its nutritional composition or environmental indicators, as it is embedded within broader socio-cultural, economic and institutional contexts [28,49,50]. Factors such as agricultural policies, food pricing structures, retail environments and public procurement systems play a decisive role in enabling or constraining access to Mediterranean-aligned food choices, thereby shaping real-world dietary behaviours and sustainability outcomes [51,52].

To capture the heterogeneity of plant-based foods and their differentiated implications for health, sustainability and policy,

Table 1. Characteristics and multidimensional sustainability implications of plant-based food categories within the Mediterranean Diet.

Category	Examples	Health Implications	Environmental Impacts	Key Limitations	Policy and Practice Implications
Fresh Seasonal Produce	Fruits, vegetables	Rich in micronutrients, fibre and antioxidants; associated with reduced risk of chronic diseases [11,53].	Low environmental footprint when locally and seasonally produced; reduced emissions and resource use [6,49].	Seasonality constraints, price variability, limited access in urban settings [44].	Strengthen local supply chains, support short food circuits and seasonal consumption [49].
Legumes and Whole Grains	Beans, lentils, chickpeas, oats, barley	High in plant protein, fibre and low glycaemic index; support metabolic health [11,54].	Low land, water and carbon footprint compared to animal protein sources [6,35].	Declining consumption, longer preparation time, cultural shifts [47].	Promote culinary education, dietary guidelines and public procurement inclusion [55].
Minimally Processed Plant Foods	Olive oil, nuts, seeds, dried fruits	Source of healthy fats and bioactive compounds; cardioprotective effects [13].	Moderate environmental impact depending on production systems [15].	Risk of overconsumption due to high energy density [3].	Promote balanced consumption through nutrition education and labelling [49].
Imported Plant-Based Products	Avocados, quinoa, exotic fruits	Nutrient-dense foods contributing to diet diversity [22].	Higher environmental impact due to transport, storage and global supply chains [4].	High carbon footprint, supply chain inequalities [50].	Encourage transparent labelling, sustainable sourcing and consumer awareness [55].
Ultra-Processed Plant-Based Products	Meat substitutes, plant-based snacks	Highly variable nutritional quality; may contain additives, refined ingredients [5,54].	High energy use, processing intensity and packaging waste [4,56].	Misperception as “healthy”, high cost, ultra-processing concerns [5].	Strengthen marketing regulation, front-of-pack labelling and reformulation policies [28].

summarises key characteristics across major food categories.

The decline in adherence to the Mediterranean Diet reflects a series of interconnected socio-economic, cultural and food-system transformations that have progressively reshaped food environments, dietary practices and traditional food cultures [17,28,47]. As illustrated in Figure 1, processes such as urbanisation, globalisation and the industrialisation of food systems have contributed to the increased availability of ultra-processed foods, changes in lifestyles and eating practices, and the erosion of culinary traditions [5,57,58]. Collectively, these transformations have contributed to reduced adherence to the Mediterranean Diet and generated both health and environmental challenges [3,45,55].

4. Role of Plant-Based Foods in the Mediterranean Diet

Plant-based foods constitute the nutritional, cultural and ecological foundation of the traditional Mediterranean Diet, representing the core components that underpin both its health-promoting properties and its sustainability profile [12,17]. Fruits, vegetables, legumes, whole grains, nuts and seeds form the basis of this dietary pattern, shaping its nutritional quality and environmental performance across diverse contexts [3,43].

From a nutritional perspective, plant-based foods provide essential micronutrients, dietary fibre, phytochemicals and unsaturated fatty acids that play a central role in metabolic regulation, cardiovascular protection and inflammation control [11,54]. High consumption of legumes and whole grains supports glycaemic stability and satiety, while fruits and vegetables supply antioxidant compounds associated with reduced oxidative stress and improved immune function [53,59]. These characteristics underpin the well-established protective effects of Mediterranean dietary patterns against chronic non-communicable diseases [60,61].

Recent evidence further highlights that the health effects of plant-based diets are strongly dependent on dietary quality and degree of processing [54,62]. Diets rich in whole and minimally processed plant foods are consistently associated with improved cardiometabolic outcomes, whereas patterns dominated by refined carbohydrates and ultra-processed plant-based products may not confer similar benefits [54,63]. Large-scale cohort and meta-analytic evidence supports the protective role of high-quality plant-based dietary patterns in reducing the risk of chronic diseases, although heterogeneity across populations remains significant [62,64].

From an environmental perspective, plant-based foods generally exhibit lower greenhouse gas emissions, reduced land and water use and diminished impacts on biodiversity compared with animal-derived products [6,7]. Life cycle assessment studies consistently demonstrate that plant-based dietary patterns generate substantially smaller ecological footprints, particularly when based on locally sourced and minimally processed foods [4,35]. Within Mediterranean food systems, the traditional reliance on seasonal produce, local varieties and low-input agricultural practices further enhances environmental resilience and reduces dependence on resource-intensive production systems [17,49].

However, the environmental performance of plant-based foods is not inherently uniform and must be interpreted within specific production and supply chain contexts [4,22]. Intensive monoculture systems, long-distance transportation, energy-intensive greenhouse production and excessive packaging may substantially increase environmental burdens, thereby challenging simplified assumptions regarding the sustainability of all plant-based foods [5,65]. Similarly, the rapid expansion of industrial plant-based alternatives raises concerns regarding energy use, ingredient sourcing and waste generation within global food systems [5,56].

Beyond their nutritional and environmental attributes, plant-based foods play a central role in Mediterranean cultural identity and culinary traditions [43,66]. Traditional dishes based on legumes, vegetables and whole grains reflect long-standing adaptive responses to local ecological conditions and socio-economic constraints, supporting culinary skills, intergenerational knowledge transmission and social cohesion [66,67]. These cultural dimensions reinforce the embeddedness of plant-based eating within everyday practices and contribute to the resilience of Mediterranean dietary patterns [43,68,69].

Nevertheless, contemporary dietary transitions have progressively eroded the centrality of plant-based foods in Mediterranean societies [5,47]. Increased consumption of ultra-processed foods, refined carbohydrates and animal-based products has displaced traditional plant-based meals, contributing to declining diet quality and increased environmental pressures [5,20]. Recent studies also indicate that adherence to plant-based dietary patterns is strongly influenced by socio-economic status, food environments and lifestyle factors, highlighting persistent inequalities in access to sustainable diets [70,71].

Importantly, the promotion of plant-based foods within the Mediterranean Diet framework should not be interpreted as a shift towards restrictive or exclusionary dietary models [3,17,72]. Instead, it reflects a flexible and culturally grounded approach that emphasises proportionality, diversity and moderation, allowing for contextual adaptation while preserving the core principles of the Mediterranean dietary pattern [3,43].

Taken together, plant-based foods function as critical integrative elements linking nutritional adequacy, environmental sustainability and socio-cultural continuity, while supporting the resilience of Mediterranean food systems [45,55,58]. As illustrated in Figure 2, plant-based foods occupy a central position within the Mediterranean Diet by connecting multiple dimensions that collectively support its sustainable adoption.

By simultaneously contributing to health promotion, environmental protection, cultural preservation and food system resilience, plant-based foods function as key integrative components within the proposed framework. Their central role helps explain how the Mediterranean Diet can generate co-benefits across multiple domains and support sustainable dietary transitions [3,55].

5. Determinants of Sustainable Adoption

The long-term adoption of the Mediterranean Diet and plant-based dietary practices is shaped by a complex and dynamic interplay of individual, social, structural and environmental determinants operating across multiple levels of influence [28,55,73]. Understanding these interacting factors is essential for explaining why evidence-based dietary models often fail to translate into sustained behavioural change in real-world settings characterised by competing constraints and contextual variability [28,55]. Recent evidence further indicates that adherence to Mediterranean dietary patterns is increasingly challenged by globalised food systems, urbanisation processes and shifting consumption behaviours, particularly among younger populations exposed to highly processed food environments [5,58].

5.1. Individual Determinants

At the individual level, dietary adoption is shaped by a combination of cognitive, motivational and behavioural factors, including nutritional knowledge, food literacy, environmental awareness and perceived self-efficacy [74,75,76]. Individuals with higher levels of food literacy and a clearer understanding of the health and environmental benefits associated with plant-based foods are more likely to adopt and maintain Mediterranean dietary patterns over time [3,77,78].

Beyond knowledge, motivation, taste preferences, culinary skills and time management capacities play a central role in shaping everyday food choices, particularly within food environments characterised by the widespread availability and convenience of ultra-processed products [5,68]. These factors interact with psychological mechanisms such as habit formation, emotional regulation and risk perception, which can either reinforce or undermine sustained dietary change [79,80].

Recent evidence further emphasises the importance of perceived behavioural control and self-regulation processes in translating intentions into consistent dietary practices, especially in contexts where competing environmental pressures are present [74,76,81]. In this sense, individual capacity to act is not solely determined by knowledge, but also by the ability to manage constraints, maintain motivation and adapt behaviours across changing circumstances [28,82].

However, despite widespread awareness of the health benefits associated with the Mediterranean Diet, empirical evidence consistently shows that knowledge alone is insufficient to ensure adherence, as behavioural change is frequently constrained by structural, social and environmental barriers [28,75]. This highlights the need to situate individual determinants within broader systems of influence, where personal capabilities interact with external conditions to shape dietary outcomes [50,55].

5.2. Social and Cultural Determinants

Food practices are deeply embedded within social relationships, cultural norms and gender roles, reflecting the relational and symbolic dimensions of eating behaviours [68]. In Mediterranean contexts, family routines, shared meals and intergenerational transmission of culinary knowledge have historically reinforced plant-based dietary patterns and contributed to the maintenance of traditional food cultures, which remain strongly associated with diet quality and adherence to the Mediterranean dietary pattern [17,25,43,66].

However, contemporary socio-cultural transformations, including changes in labour patterns, increased time scarcity, urban lifestyles and evolving household structures, have progressively weakened these traditional practices [28,47,58]. The erosion of culinary traditions, combined with increased reliance on convenience foods and ultra-processed products, reflects broader nutritional and lifestyle transitions that undermine the social and cultural foundations of sustainable dietary behaviours [5,47].

Social norms and peer influences play a critical role in shaping dietary expectations and consumption patterns, particularly in contexts where food choices are socially negotiated, culturally embedded and identity-driven [67,68]. In this sense, the social acceptability of plant-based diets and Mediterranean dietary practices can either facilitate or constrain their adoption depending on cultural values, symbolic meanings and group-level dynamics [21,83,84].

Social support networks, including family systems, peer groups, educational environments and healthcare professionals, constitute key enabling factors for sustained dietary change by providing both instrumental and normative reinforcement [28,50,55]. Conversely, conflicting household preferences, weakening of shared meals and reduced intergenerational food transmission may compromise adherence and reinforce less sustainable consumption patterns, particularly among younger, urbanised and socio-economically diverse populations [20,85,86].

5.3. Structural and Economic Determinants

Structural and economic conditions exert a profound influence on dietary behaviour by shaping food availability, affordability and accessibility within everyday food environments [28,50,55]. Price differentials between fresh, minimally processed foods and ultra-processed products, combined with retail concentration and globalised supply chain dynamics, play a decisive role in influencing consumer choices and dietary patterns across populations [4,5,6]. These structural drivers contribute to the normalisation of energy-dense, nutrient-poor diets, particularly in urban and economically constrained settings, where food environments are increasingly dominated by ultra-processed products and commercial influences [5,28,57].

Recent evidence highlights that access to healthy and sustainable diets remains a major global challenge, with billions of individuals unable to afford nutritionally adequate diets, thereby constraining the adoption of Mediterranean dietary patterns across diverse socio-economic contexts [44,45,50]. These economic barriers are further exacerbated by structural inequalities in food systems, including disparities in food distribution, territorial accessibility, infrastructure and market integration, which disproportionately affect vulnerable populations and reinforce dietary inequalities [55].

In parallel, globalised food markets and industrialised food systems have significantly increased the availability, affordability and aggressive marketing of ultra-processed foods, reinforcing dietary patterns that are both unhealthy and environmentally unsustainable [5,28,56]. These conditions create structural constraints that limit individuals’ capacity to adopt healthier and more sustainable dietary practices, regardless of personal motivation or knowledge, thereby highlighting the limitations of individual-centred approaches to behaviour change [28,55,87].

At the same time, structural environments may function as enabling systems when supported by coherent governance frameworks and policy alignment across sectors [49,50]. Public policies play a decisive role in shaping food environments through mechanisms such as agricultural subsidies, fiscal instruments, food labelling regulations, public procurement strategies and urban planning interventions [28,55]. Policies that incentivise local production, short supply chains and agroecological systems can enhance the availability, affordability and cultural relevance of plant-based foods, thereby facilitating healthier and more sustainable dietary patterns [49,51].

Conversely, fragmented or misaligned policy environments may reinforce structural barriers, perpetuate socio-economic inequalities and hinder the transition towards sustainable diets, particularly when economic and commercial interests override public health and environmental priorities [28,50,55]. These dynamics highlight the need for integrated, cross-sectoral policy approaches capable of aligning food system transformation with health, sustainability and equity objectives [3,28,49,50,55].

5.4. Environmental Awareness and Perception

Environmental awareness has emerged as an increasingly important determinant of dietary behaviour in the context of climate change, resource scarcity and sustainability transitions [3,22,55]. Individuals who recognise the links between food consumption and environmental impacts, including greenhouse gas emissions, land use, water use and biodiversity loss, are more likely to adopt plant-based and Mediterranean dietary patterns [6,7,58].

Empirical evidence indicates that dietary patterns aligned with Mediterranean principles are associated with lower environmental impacts, including reduced greenhouse gas emissions, lower resource use and improved biodiversity outcomes [7,14,35]. However, the translation of environmental awareness into consistent dietary practices remains uneven across populations and contexts, reflecting variability in access, motivation and enabling conditions [58,88,89].

This discrepancy reflects the well-documented value–action gap in sustainable consumption, whereby positive environmental attitudes do not necessarily result in behavioural change due to competing priorities, habitual practices and structural constraints [28,88]. Within this context, perceived environmental efficacy plays a critical mediating role, as individuals are more likely to adopt sustainable dietary behaviours when they believe that their actions can contribute meaningfully to environmental outcomes [74,88].

At the same time, environmental motivations are shaped by social norms, cultural expectations and structural conditions, highlighting the interdependence between individual awareness and broader food system dynamics [50,55,68]. Without supportive environments, including accessible plant-based food options and enabling policy frameworks, environmental awareness alone is unlikely to sustain long-term dietary change [22,28,49].

Collectively, these processes operate within a dynamic and interdependent system characterised by feedback mechanisms and contextual dependencies that shape dietary practices over time [28,73,90]. As such, the sustainability of the Mediterranean Diet is influenced by a combination of structural, socio-economic and behavioural factors that extend beyond individual control, reinforcing the need for integrated and systemic approaches [50,55,58].

Consequently, interventions targeting single determinants are unlikely to generate durable behavioural change, as they fail to address the complexity of food systems and the multiple constraints faced by individuals [28,50]. Instead, coordinated multi-level strategies that simultaneously address individual capacities, social norms, structural environments and environmental awareness are required to support the sustainable adoption of the Mediterranean Diet and plant-based dietary practices [3,49,55].

6. The Conceptual Framework for Sustainable Adoption

Although the four domains are analytically distinct, they operate through continuous interactions. Individual capacities primarily reflect cognitive, motivational and practical resources; socio-cultural contexts encompass shared norms, identities and social practices; structural environments refer to the material, economic and institutional conditions shaping food choices; and ecological awareness captures environmental values, sustainability beliefs and perceived environmental responsibility. Ecological awareness functions as a bridging domain, linking individual perceptions with broader socio-environmental concerns and sustainability goals.

6.1. Core Domains of the Framework

The proposed framework is structured around four interrelated domains that jointly shape dietary behaviour: individual capacities, socio-cultural contexts, structural environments and ecological awareness [28,73]. These domains represent distinct yet interconnected spheres of influence operating across multiple levels, from personal resources and social practices to broader institutional and environmental conditions [50,55]. Rather than acting independently, these domains interact through dynamic and reciprocal processes that influence both short-term food choices and long-term dietary trajectories [90,91]. Changes within one domain may generate cascading effects across others, reinforcing or constraining the adoption of Mediterranean and plant-based dietary practices [28,90]. This integrative perspective allows dietary behaviour to be understood as an emergent property of complex systems, shaped by continuous interactions between individual agency, social dynamics, structural constraints and environmental considerations [55,73].

6.1.1. Individual Capacities

The individual domain encompasses cognitive, motivational and practical resources that enable dietary change and shape behavioural responses to food environments [75,77]. Key components include nutritional knowledge, food literacy, culinary competence, health motivation, environmental values and perceived self-efficacy, which collectively influence individuals’ capacity to engage with sustainable dietary practices [3,74]. These capacities determine individuals’ ability to interpret dietary information, navigate increasingly complex food environments and translate intentions into sustained behaviours [28,81]. Inadequate cooking skills, low confidence in meal preparation and fragmented knowledge may undermine adherence, even when favourable attitudes towards Mediterranean and plant-based dietary patterns are present [75,77]. Furthermore, reliance on information-based interventions in the absence of practical skill development and behavioural support may result in short-term compliance rather than sustained change, particularly in contexts characterised by structural constraints [28,81]. Importantly, individual capacities are dynamic and evolve through education, social interaction and experiential learning. This highlights the importance of lifelong nutrition education and community-based, participatory approaches in supporting sustainable dietary transitions [50,55].

6.1.2. Socio-Cultural Contexts

The socio-cultural domain reflects the relational and symbolic dimensions of food practices, shaping how dietary behaviours are constructed, shared and maintained [67,68,92]. Family routines, gender roles, cultural traditions, social norms and peer influences play a central role in structuring dietary expectations and everyday food choices [68,92,93]. In Mediterranean societies, shared meals and intergenerational transmission of culinary knowledge have historically reinforced plant-based dietary patterns and supported the continuity of traditional food cultures, contributing to higher adherence to Mediterranean dietary patterns and improved diet quality [17,43,66]. However, socio-economic transformations, including urbanisation, labour market pressures and changing household structures, have progressively disrupted these practices, contributing to the erosion of traditional dietary behaviours [5,28,47,58,94]. Social support functions as a key moderating mechanism, as collective engagement, shared practices and positive role modelling can strengthen adherence to Mediterranean and plant-based diets and facilitate behavioural maintenance over time [55,95]. Conversely, social fragmentation, conflicting preferences and the decline of shared eating practices may undermine long-term dietary change and reinforce less sustainable consumption patterns, particularly among younger and more urbanised populations [85,86,94].

6.1.3. Structural Environments

The structural domain encompasses the material, institutional and economic conditions under which food choices are made, including food availability, pricing systems, retail infrastructures, marketing practices and regulatory frameworks [50,55,96]. These factors define the “choice architecture” within which individuals operate, shaping available options and constraining behavioural autonomy [28,97,98]. Food environments characterised by a high availability and accessibility of ultra-processed products systematically undermine the adoption of healthy and sustainable dietary patterns, regardless of individual motivation [50,87]. Evidence shows that these products contribute to environmental pressures while reshaping consumption patterns through affordability, convenience and intensive marketing strategies [4,5,56]. Conversely, supportive infrastructures, including local food systems, short supply chains and sustainable public procurement, can enhance access to Mediterranean-aligned foods and promote plant-centred dietary practices [49,55,94]. Structural environments thus function not only as constraints but also as enabling systems that expand opportunities for sustainable choices and reinforce behavioural change through improved accessibility and availability [94,99]. Policy coherence across agricultural, health and environmental domains is essential to support these transitions, as fragmented governance structures may perpetuate structural barriers, reinforce inequalities and limit the effectiveness of interventions [49,50,94,100].

6.1.4. Ecological Awareness

The ecological awareness domain captures individuals’ perceptions of environmental impacts, climate responsibility and ecosystem vulnerability associated with food consumption [3,101]. It reflects the extent to which sustainability considerations are integrated into dietary decision-making processes [102,103]. Despite increasing awareness, its translation into consistent behaviour remains uneven across contexts [88,104]. This gap is often explained by competing priorities, habitual practices and structural constraints that limit the implementation of sustainability-oriented intentions [28,105]. Perceived environmental efficacy acts as a key mediating factor, as individuals are more likely to adopt sustainable diets when they believe their actions can have meaningful environmental impact [74,88]. However, environmental motivation alone is insufficient without supportive social norms and enabling structural conditions [50,55]. The framework therefore emphasises that alignment between ecological awareness, individual capacities, socio-cultural dynamics and structural environments is essential to sustain long-term dietary change [28,55].

6.2. Dynamic Interactions and Feedback Mechanisms

A central feature of the proposed framework is its emphasis on dynamic interactions and reciprocal feedback mechanisms across domains, reflecting the complexity of dietary behaviour within socio-ecological systems [90,91]. Rather than following linear cause–effect relationships, dietary practices are understood as outcomes of adaptive processes in which changes in one domain can influence others [73,91].

These interactions generate reinforcing and balancing feedback loops that shape the stability and evolution of dietary behaviours over time [28,90]. For example, participation in community-based cooking programmes may enhance individual capacities, strengthen social cohesion and increase awareness of local food systems, thereby creating synergistic effects that support sustainable dietary practices [55,81]. Such reinforcing mechanisms can increase behavioural confidence, facilitate habit formation and support long-term adherence to Mediterranean-aligned diets [79,81].

Conversely, destabilising feedback processes may emerge in contexts characterised by adverse socio-economic conditions, where structural constraints interact with individual and social factors to undermine dietary change [28,50]. Economic insecurity, time scarcity and social isolation can reduce motivation, weaken support networks and increase reliance on convenience and ultra-processed foods, progressively shifting dietary practices away from plant-based patterns [5,28].

These processes are often cumulative and path-dependent, constraining future behavioural options and reinforcing existing consumption patterns [90,91]. Over time, unsustainable practices may become embedded within routines, environments and social norms, increasing resistance to change [28,68].

Within this perspective, dietary adoption is conceptualised as a continuous process of negotiation between individual intentions, social influences and structural conditions, rather than a discrete outcome [55,73]. Sustainable change is therefore understood as a dynamic equilibrium that depends on ongoing reinforcement through supportive environments, institutional coherence and policy alignment [49,50].

6.3. Mediating Role of Plant-Based Foods

Within the proposed framework, plant-based foods occupy a central mediating position, functioning as integrative connectors that link individual, socio-cultural, structural and ecological domains within dietary systems [3,17]. Their multidimensional attributes enable the simultaneous activation of behavioural, symbolic and material pathways that support the sustainable adoption of Mediterranean dietary patterns [55,90].

From a health perspective, regular consumption of plant-based foods is associated with improvements in metabolic regulation, energy balance and weight management, reinforcing behavioural engagement through perceived physiological benefits and positive health feedback [11,54]. These embodied outcomes contribute to strengthening perceived self-efficacy and behavioural confidence, thereby supporting the maintenance of dietary change over time [74,79].

From an environmental perspective, awareness of the reduced ecological footprints associated with plant-based diets, including lower greenhouse gas emissions and resource use, can enhance moral engagement and sustainability-oriented identities [6,7]. However, the translation of environmental concern into sustained dietary practices remains contingent upon enabling structural conditions and supportive social norms, reflecting the persistent value–action gap observed in sustainable consumption behaviours [28,88].

Culturally, plant-based foods are embedded within traditional culinary practices, seasonal food systems and shared eating rituals that reinforce identity, belonging and social cohesion within Mediterranean contexts [43,66]. These symbolic and relational dimensions strengthen emotional attachment to dietary routines and increase their resilience in the face of competing market influences and lifestyle changes [67,68].

Importantly, the mediating role of plant-based foods is not uniform but is shaped by factors such as food quality, degree of processing, production systems and socio-economic accessibility [5,56]. Highly processed plant-based products, globally traded commodities and premium-priced foods may weaken the alignment between health, environmental and social objectives, highlighting the need to distinguish between minimally processed and ultra-processed plant-based options within sustainability frameworks [5,65].

Through these convergent and context-dependent mechanisms, plant-based foods function as leverage points within the system, generating cumulative reinforcement effects that stabilise long-term dietary adoption [90,91]. When nutritional benefits, environmental values and cultural meanings are simultaneously activated and aligned with supportive environments, plant-based practices can facilitate system-level transformations towards more sustainable and resilient food systems [50,55].

6.4. Temporal Dynamics and Life-Course Transitions

The proposed framework incorporates a temporal dimension, recognising that dietary practices evolve across the life course in response to changing social roles, economic conditions and health trajectories [68,106]. Rather than remaining stable over time, food routines are continuously reshaped through cumulative experiences, social transitions and shifting environmental contexts, reflecting the dynamic nature of dietary behaviour within complex systems [73,90].

Life-course transitions such as entering higher education, parenthood, changes in employment status, illness, migration or retirement frequently disrupt established dietary patterns and domestic food practices [106,107]. These transitional phases are often characterised by increased uncertainty, time constraints and renegotiation of household responsibilities, which may weaken existing support structures for Mediterranean-aligned dietary practices [28,68].

At the same time, these periods represent critical windows of opportunity for behavioural reconfiguration, as disruptions in routine may reduce habitual inertia and increase openness to change [79]. Empirical evidence suggests that life-course transitions are particularly sensitive moments for habit discontinuity and reformation, during which individuals may be more receptive to adopting new dietary behaviours [81,108].

Targeted interventions delivered during these phases, including tailored nutrition counselling, community-based support programmes and institutional food provision strategies, may therefore facilitate the adoption and consolidation of more sustainable dietary practices [49,55]. Such interventions can leverage transitional periods to align individual motivation with supportive social and structural conditions, enhancing the likelihood of long-term adherence [28,50].

Conversely, unaddressed disruptions may reinforce unsustainable habits through processes of routinisation and behavioural reinforcement, leading to long-term path dependencies that constrain future dietary change [79,91]. Early and repeated exposure to energy-dense, convenience-oriented food environments during transitional periods may exert lasting effects on preferences and consumption patterns, reinforcing trajectories associated with ultra-processed food consumption [5,28].

These dynamics highlight the importance of anticipatory, adaptive and life-course-sensitive policy responses that account for temporal variability in dietary behaviour [50,55]. Integrating dietary sustainability considerations into education systems, workplace environments, healthcare services and social protection frameworks may enhance the capacity of individuals and households to navigate transitions without compromising long-term dietary quality [28,49,109].

6.5. Implications for Intervention Design

By elucidating multi-level determinants and interaction mechanisms, the proposed framework provides a structured foundation for designing integrated interventions aimed at promoting the sustainable adoption of the Mediterranean Diet within complex food systems [37,73]. Rather than targeting isolated behavioural factors, effective strategies must simultaneously engage individual capacities, socio-cultural dynamics, structural conditions and ecological values to reflect the systemic nature of dietary behaviour [55,80,100].

Interventions that rely exclusively on information provision or individual motivation are unlikely to produce durable effects, particularly in environments characterised by strong structural constraints and commercial pressures [5,28]. Such approaches risk reinforcing narratives of individual responsibility while leaving underlying determinants unaddressed, thereby limiting their effectiveness and scalability [50,55].

In contrast, coordinated multi-component programmes that integrate nutrition education, culinary skill development, community mobilisation, food environment restructuring and policy incentives are more likely to generate synergistic and self-reinforcing effects across domains [81,90,110]. Aligning educational initiatives with supportive retail environments, sustainable public procurement strategies and regulatory measures can enhance intervention coherence and reinforce behavioural change over time [28,49].

The framework further emphasises the importance of context-sensitive adaptation, recognising that dietary behaviours are shaped by local socio-economic conditions, cultural practices and institutional arrangements [55,90]. Interventions designed without consideration of contextual variability are unlikely to achieve sustained impact across diverse populations and settings [28,50].

Participatory design processes involving communities, practitioners and policymakers can strengthen intervention relevance, legitimacy and long-term effectiveness by aligning strategies with lived experiences and local food system dynamics [2,55,90]. Such approaches facilitate co-creation of solutions and enhance the integration of behavioural, social and structural levers within intervention design [50,73].

By guiding the alignment of these multi-level components, the framework supports the development of interventions that move beyond short-term behaviour modification towards systemic transformation of food practices [28,55,73]. This shift is essential for addressing the complexity of contemporary food systems and enabling sustainable dietary transitions at population level [49,50].

6.6. Conceptual Validation and Theoretical Positioning

The proposed framework is theoretically grounded in established models of health behaviour, social practice theory and socio-ecological approaches to health and sustainability, providing a multidimensional basis for understanding dietary change [28,73,111]. By integrating these complementary perspectives within a food systems framework, the model transcends disciplinary boundaries and advances a more comprehensive and context-sensitive understanding of sustainable dietary adoption [50,55].

From a behavioural perspective, the framework aligns with theories emphasising self-efficacy, habit formation and motivational processes, while extending these approaches through the explicit incorporation of structural and institutional determinants that shape behavioural possibilities [74,100]. This integration allows for a more realistic representation of dietary behaviour as both agent-driven and context-dependent, rather than solely the outcome of individual decision-making [28,55].

From a social practice perspective, the framework recognises that dietary behaviours are embedded within material, symbolic and relational dimensions of everyday life, reflecting shared practices rather than isolated individual choices [68,96]. This perspective highlights the importance of routines, social norms and cultural meanings in shaping food consumption patterns and sustaining behavioural change over time [67,80,92].

Similarly, socio-ecological models are extended through the incorporation of environmental ethics and food system governance, positioning dietary behaviour within broader socio-economic, political and environmental contexts [28,50,55]. This integrative positioning reflects the growing recognition that sustainable dietary transitions require alignment between individual behaviour, social practices, structural conditions and policy environments [3,28,49].

By combining these theoretical perspectives, the framework enhances its explanatory scope and mitigates the limitations associated with single-theory approaches that prioritise either individual agency or structural determinism [73,90,112]. The model instead adopts a relational and systems-oriented perspective that captures the complexity of real-world food practices and their embeddedness within dynamic and adaptive systems [90,91].

Continuous refinement through empirical validation, participatory stakeholder engagement and cross-cultural comparison will be essential to strengthen the theoretical coherence, external validity and practical relevance of the framework [50,55]. Longitudinal and comparative research designs may further elucidate how interactions between domains evolve across diverse socio-economic, cultural and institutional contexts [28,73].

As illustrated in Figure 3, the framework positions sustainable dietary adoption at its core, with plant-based foods acting as a central mediating component that connects domains and reinforces behavioural pathways [3,17]. The four domains are represented as interconnected spheres reflecting individual capacities, socio-cultural contexts, structural environments and ecological awareness, while bidirectional arrows illustrate reciprocal influences and feedback mechanisms between domains and the adoption process [90,91]. The outer layer represents life-course and temporal dynamics, emphasising that dietary practices evolve across critical transitions and contextual conditions [68,106].

To enhance analytical clarity and facilitate practical application,

Table 2. Core domains, determinants, barriers and intervention implications for the sustainable adoption of the Mediterranean Diet.

Domain	Key Determinants	Main Barriers	Policy and Practice Implications
Individual Capacities	Food literacy, culinary skills, motivation, self-efficacy, health and environmental knowledge [27,55,74,77,94].	Time constraints, low confidence, limited cooking skills, fragmented or inconsistent information [27,28,50,75].	Nutrition education, culinary training, experiential learning and behaviour-change interventions [28,81,94,113],
Socio-Cultural Contexts	Family practices, social norms, cultural traditions, peer influence, gender roles [55,67,68,92].	Conflicting household preferences, erosion of traditions, social pressure, reduced shared meals [5,36,47,58].	Community-based interventions, social marketing strategies, family-oriented and culturally adapted programmes [28,50,94,96].
Structural Environments	Food availability, affordability, pricing systems, retail infrastructure, public procurement, regulation [44,82,114].	High cost of fresh foods, unequal access, dominance of ultra-processed products, market concentration [5,40,50,57].	Subsidies for healthy foods, sustainable public procurement, food environment regulation and fiscal policies [45,50,94].
Ecological Awareness	Environmental values, climate risk perception, moral engagement, perceived behavioural efficacy [3,88,94].	Low perceived individual impact, information overload, competing priorities and habitual behaviours [28,50,88].	Sustainability communication, eco-labelling, behavioural nudges and public awareness campaigns [49,89,94].

synthesises the core domains, key determinants, major barriers and corresponding policy and practice implications associated with the sustainable adoption of the Mediterranean Diet [50,55].

7. Implications for Policy and Practice

The proposed conceptual framework provides a strategic foundation for the design of integrated and multisectoral interventions aimed at promoting the sustainable adoption of the Mediterranean Diet and plant-based dietary practices within complex food systems [28,50,55]. The framework highlights how traditional, siloed interventions fail by neglecting the complex interplay between individual, social, and structural factors. Instead, it suggests that integrated, systems-based approaches may be more effective than isolated interventions for supporting long-term dietary transformation [28,50,90].

In the field of public health, nutrition education programmes should move beyond information provision and incorporate experiential learning, culinary skill development and critical food literacy to effectively support behavioural change [27,50,77,113]. School-based interventions, community cooking initiatives and workplace health programmes can play a central role in fostering long-term engagement with Mediterranean-aligned dietary practices, particularly when embedded within supportive food environments and broader community contexts [27,28,55,81].

From a food policy perspective, coherent and cross-sectoral regulatory frameworks are essential to enable sustainable dietary choices and reduce structural barriers [49,50,55]. Agricultural and fishery policies that incentivise local production, short supply chains and agroecological practices can enhance the availability, affordability and resilience of plant-based food systems [49,50]. In addition, public procurement standards in schools, hospitals and other public institutions may contribute to normalising Mediterranean dietary patterns while supporting local sustainable markets and supply chains [28,50].

Urban planning, transport policies and retail regulation also play a critical role in shaping everyday food environments and influencing dietary behaviour [28,115]. The promotion of fresh food markets, neighbourhood retail infrastructures and accessible urban food environments can facilitate healthier and more sustainable food practices by improving both physical and economic access to plant-based foods [50,94]. In parallel, transparent food labelling, restrictions on misleading environmental claims and responsible marketing policies are necessary to counteract commercial pressures associated with ultra-processed food environments [5,28].

In clinical and primary care settings, health professionals should adopt integrated counselling approaches that address the nutritional, social and environmental dimensions of dietary behaviour [3,55,94,116]. Tailored interventions that consider household dynamics, cultural preferences and socio-economic constraints are more likely to support sustained behavioural change and improve adherence to Mediterranean dietary patterns [28,76,89]. Interdisciplinary collaboration between healthcare providers, social services and community organisations may further enhance intervention effectiveness by aligning individual-level support with broader structural and social determinants [29,94,100].

Overall, the framework supports a shift from isolated behavioural interventions towards systemic policy strategies that align health promotion, environmental sustainability and social equity objectives within food systems [7,28,100]. This transition is consistent with global calls for food system transformation that emphasise integrated, multi-level approaches to addressing the complex drivers of dietary behaviour [3,8,50].

To facilitate the translation of the proposed framework into actionable strategies,

Table 3. Policy, practice and system-level implications of the conceptual framework for sustainable adoption of the Mediterranean Diet.

Level	Target Area	Recommended Actions	Expected Impact
Individual	Food literacy, skills and behaviour	Culinary education, experiential learning, personalised nutrition counselling and behaviour-change interventions [77,81,94].	Increased self-efficacy, improved dietary quality and sustained adherence to Mediterranean dietary patterns.
Community	Social norms, cultural practices and support networks	Community cooking programmes, peer support networks, social marketing and culturally adapted local initiatives [28,50,55].	Strengthened social reinforcement, improved acceptability and long-term maintenance of dietary change.
Institutional	Schools, workplaces and public settings	Healthy catering standards, sustainable menus, public procurement policies aligned with Mediterranean principles [28,49,50].	Normalisation of plant-based dietary patterns and increased population-level exposure to healthy and sustainable foods.
Market	Food environments and supply chains	Regulation of food marketing, incentives for local and seasonal products, support for short supply chains and retail environment redesign [5,28,50].	Improved availability and accessibility of sustainable foods and reduced exposure to ultra-processed products.
Policy	Governance, regulation and food systems	Integrated food policies, agricultural incentives, fiscal measures, eco-labelling and cross-sectoral policy alignment [49,50,94].	System-level alignment between health, environmental and socio-economic objectives and reduction of structural barriers.
Healthcare	Primary care and public health services	Integrated dietary counselling, interdisciplinary support, preventive care strategies and sustainability-oriented nutrition guidance [3,50,94].	Improved prevention and management of diet-related diseases and reinforcement of sustainable dietary behaviours

synthesises the main multi-level implications derived from the present analysis, linking domains, determinants and intervention pathways across different levels of governance [50,94]. This multi-level perspective highlights the need for coordinated actions across sectors and scales to support sustainable dietary transitions. However, the effectiveness of these strategies depends on context-specific institutional capacities, governance arrangements and socio-economic conditions, reinforcing the importance of adaptive and context-sensitive implementation approaches [28,49,90].

This multi-level synthesis underscores that sustainable dietary transitions require coordinated action across individual, social, institutional and policy domains rather than isolated interventions. The proposed framework highlights that sustainable dietary transitions cannot be achieved through individual behaviour change alone. Instead, coordinated actions across multiple levels of governance and society are required to address the diverse determinants influencing dietary practices. As illustrated in Figure 4, effective interventions should simultaneously target policy environments, food systems, institutions, communities and individual capacities to support the sustainable adoption of the Mediterranean Diet [28,50,55].

Figure 4 translates the proposed framework into a set of interconnected intervention pathways operating across multiple levels of governance and society. This perspective reinforces the need for integrated and cross-sectoral approaches capable of aligning public health, environmental sustainability and food system objectives. By acting simultaneously across policy, market, institutional, community and individual domains, interventions are more likely to generate synergistic effects and support long-term dietary change than isolated or single-component strategies [28,49,55].

8. Research Agenda

Future research should prioritise the empirical validation and contextual adaptation of the proposed conceptual framework across diverse socio-cultural, economic and geographical settings in order to strengthen its applicability and external validity [50,55,90]. Comparative and cross-national studies are particularly relevant to examine how interactions between individual, socio-cultural, structural and ecological determinants evolve over time and shape dietary trajectories under different institutional and policy environments [28,57,71]. Such approaches can support the identification of context-specific drivers and barriers, while also revealing transferable mechanisms that may facilitate sustainable dietary adoption across populations [50,90,94].

The development and validation of standardised measurement instruments to operationalise the key components of the framework represent a critical priority for advancing research in sustainable nutrition [77,94]. The availability of robust and harmonised tools to assess food literacy, ecological awareness, structural constraints and social practices would enhance cross-study comparability and support cumulative knowledge generation across different research contexts [55,82,116].

Mixed-methods research designs integrating quantitative modelling, longitudinal data and in-depth qualitative approaches are essential to capture the complexity of dietary behaviours and the mechanisms underlying sustainable adoption [73,90,117]. In particular, systems-based modelling approaches, including agent-based models and network analyses, may provide valuable insights into feedback processes, non-linear dynamics and potential leverage points for intervention within food systems [91,118].

Experimental, quasi-experimental and natural experiment designs should be further employed to test multi-level interventions informed by the framework in real-world settings, with particular attention to implementation processes, contextual variability and behavioural drivers [28,81,87]. Evaluating scalability, cost-effectiveness and long-term sustainability remains essential for translating research evidence into effective and actionable policy strategies [45,49,50,94].

Further research is also needed to examine the economic, social and distributional implications of plant-based Mediterranean dietary patterns, including affordability, accessibility, labour conditions and impacts on food system equity [3,45,49]. The transition towards plant-based diets may generate both opportunities and trade-offs across food value chains, requiring integrated assessments that explicitly consider socio-economic impacts, environmental trade-offs and policy alignment [2,6,40].

In addition, greater attention should be given to behavioural and contextual determinants shaping dietary choices across different population groups, particularly among younger consumers, for whom affordability, convenience, social norms and cultural familiarity represent key influencing factors [68,85,86]. Understanding these dynamics is essential for designing interventions that are both effective and socially acceptable across diverse settings [55,81].

Finally, future research should further explore the role of governance mechanisms, policy coherence and private-sector engagement in shaping sustainable dietary transitions within complex food systems [28,50,94]. Analysing the effects of fiscal policies, regulatory frameworks, public procurement strategies and corporate practices on dietary sustainability remains critical for advancing systemic change and ensuring equitable food system transformation [3,49,50]. In parallel, greater attention should be given to inconsistencies in the literature and to context-dependent trade-offs associated with sustainable dietary transitions, in order to avoid oversimplified interpretations of sustainability outcomes and strengthen the robustness of future evidence [55,90].

9. Limitations

This study presents several limitations. As a conceptual narrative review, the proposed framework depends on the selection and interpretation of the literature. Although a structured search strategy was applied, the absence of a formal systematic review protocol may limit the comprehensiveness and reproducibility of the synthesis. In addition, the framework has not been empirically validated. The lack of primary data prevents the assessment of causal relationships and the evaluation of the model’s predictive capacity, and it should therefore be interpreted as a theoretically informed construct. The framework may also be sensitive to contextual variability, as it does not fully capture differences in socio-economic conditions, cultural practices and food system structures across settings. Furthermore, some macro-level drivers, including political and economic factors, are only partially addressed. Despite these limitations, the proposed framework offers a coherent and integrative perspective that can inform future empirical research, policy development and the design of multi-level interventions for sustainable dietary transitions. However, it has not yet been empirically validated and should therefore be regarded as a theoretical model requiring further testing, contextual adaptation and validation across diverse populations and settings.

10. Conclusions

This study proposes an integrated conceptual framework to explain the sustainable adoption of the Mediterranean Diet centred on plant-based foods within contemporary food systems. By combining individual, socio-cultural, structural and ecological dimensions, the framework highlights the complexity and interdependence of factors shaping dietary behaviour. A key contribution of this work lies in the positioning of plant-based foods as mediating components that connect health, environmental sustainability and cultural practices within a systems perspective. In addition, the integration of feedback mechanisms and life-course dynamics provides a more nuanced understanding of dietary change as a non-linear and context-dependent process. These insights suggest that sustainable dietary transitions require coordinated, multi-level strategies that go beyond isolated behavioural interventions and address the broader structural and social conditions shaping food choices. Overall, the framework offers a theoretically grounded basis for advancing research, informing policy and supporting the design of integrated and context-sensitive interventions aimed at promoting sustainable dietary patterns.