Promoting Healthy and Sustainable Eating Behaviors: Multidimensional Interventions Across Childhood and Young Adulthood

Introduction: Unhealthy and unsustainable dietary patterns represent a major public health challenge, contributing to the rising burden of obesity, non-communicable diseases, and environmental degradation. Access to healthy and sustainable diets is shaped by complex interactions between individual, social, and environmental determinants, which vary across the life course and across contexts. Evidence increasingly shows that isolated, individual-focused interventions are insufficient to produce equitable and lasting changes in dietary behaviors, highlighting the need for context-specific and multidimensional strategies. Aim: This thesis aims to explore how multidimensional, context-adapted interventions can promote access to healthy and sustainable eating behaviors across different life stages and population groups. Specifically, it examines the feasibility, acceptability, and implications for policy of interventions implemented in school settings (childhood), university food environments (young adulthood), and collective catering contexts for individuals with clinical and functional vulnerabilities. Methods: Three applied intervention studies were conducted. The LIVELY project implemented a school-based nutrition education program with family involvement in a multicultural, low socioeconomic urban setting. The FOOD-HACK project tested environmental nudging strategies in a university cafeteria to promote healthier and more sustainable food choices. The AUT-MENU project evaluated the feasibility of sensory-informed, nutritionally tailored menu adaptations combined with caregiver education in collective catering settings for individuals with autism spectrum disorder. Quantitative and qualitative data were collected using anthropometric measures, questionnaires, food consumption assessments, and acceptability evaluations, depending on the context. Results: Across the three studies, interventions were feasible and generally well accepted by participants and stakeholders. While short-term changes in dietary behaviors and consumption were modest and context-dependent, all interventions demonstrated the potential to improve food environments without compromising acceptability. School-based education enhanced nutrition knowledge and engagement; nudging strategies influenced food selection toward healthier and more sustainable options; and sensory-informed menu adaptations supported the inclusion of nutritionally relevant foods in vulnerable populations. Structural and contextual factors, including institutional constraints, cultural diversity, and sensory sensitivities, strongly influenced outcomes. Discussion: Taken together, the findings indicate that improving access to healthy and sustainable diets requires flexible, context-sensitive, and integrated approaches rather than uniform solutions. The evidence supports a shift from isolated educational actions toward multidimensional strategies that combine education, environmental modification, and policy support across the life course. These results provide a basis for informing food policies that prioritize feasibility, equity, and sustainability, and that can be adapted and scaled across diverse institutional settings to promote healthier and more inclusive food environments.