Understanding sustainable diets in older Vietnamese migrant communities: cultural and social drivers of food choices in Sydney, Australia

Introduction Sustainable diets encompass environmental, nutritional, cultural and economic dimensions and are central to planetary and human health. However, little is known about how older migrant communities understand and engage in sustainable diets. Vietnamese migrants represent a large and aging population in Australia, yet the sociocultural and structural factors shaping their engagement with sustainable diets remain underexplored. This study aims to examine how Vietnamese migrants conceptualize sustainable diets and to identify the sociocultural and environmental influences shaping their food choices and practices.Method This study draws on a sustainable diet framework and dietary acculturation theory to examine how migration and changing food environments shape food choices. A critical realist approach positions food choices as embedded within broader sociocultural and structural contexts. Sixteen Vietnamese migrants aged ≥40 years participated in six in-person data collection sessions conducted in Sydney, Australia. Discussions were conducted in Vietnamese by native-speaking facilitators and analyzed using reflexive thematic analysis.Results The participants demonstrated limited familiarity with sustainable diets, often associating sustainability with waste management and food quality. Food choices are shaped by priorities of health, quality, and trust in the Australian food system. The motivation to change for environmental reasons was low, reflecting skepticism about impact and limited access to Vietnamese-language information.Conclusion These findings highlight the need for culturally and contextually grounded approaches that engage with participants’ existing food values and practices. Future research should use co-design approaches to identify and evaluate culturally meaningful ways of communicating sustainable diets within Vietnamese migrant communities.