Psychological Theoretical Frameworks of Healthy and Sustainable Food Choices: A Systematic Review of the Literature

Background: Non-sustainable diets are associated with several environmental and health-related problems. Psychology research is interested in the study of food choice determinants, and several theoretical frameworks have been applied to study mechanisms underlying behavioral change and to develop theory-based interventions. The present systematic review is aimed at reviewing the existing literature on the psychological theoretical frameworks used to study sustainable and/or healthy food choices and their application for the development of interventions promoting such food choices, both in general and clinical populations. Methods: A systematic search of PubMed, PsycInfo, and Scopus was conducted according to PRISMA criteria. Results: Forty-five articles met the inclusion criteria and thirty-five theoretical frameworks emerged, mostly pertaining to social psychology and with the most widely used being the Theory of Planned Behavior. The majority of studies had a cross-sectional design, were conducted in general populations, and focused on healthy food choices. Only a few studies tested theory-based interventions. Internal (i.e., self-efficacy, personal values, and motivation) and external (i.e., peers, family, and social media influence) factors emerged as relevant healthy and sustainable eating determinants. Conclusions: The current review underlines that an integrative perspective combining prompts from different psychology fields is needed in order to identify the psychological factors influencing food choices and to develop psychological interventions for the promotion of more sustainable diets.