Navigating sustainable consumer behavior: A comprehensive study on motivators and message strategies for suboptimal food consumption

The global challenge of food waste drives innovative approaches, especially in post-production, with businesses focusing on selling suboptimal but edible food products. This dissertation investigates consumer motivations and examines the effectiveness of message appeal and sources in influencing responses through an exploratory sequential mixed-method approach. It starts with qualitative interviews to understand motivations related to consuming suboptimal foods and then develops two quantitative studies to test a model of sustainability communication for suboptimal foods. The objectives are: (1) to clarify consumer motivations for reducing food waste and choosing suboptimal foods through a qualitative study, and (2) to assess the impact of message appeal (sensual, guilty, informational) and source (company or social media influencers) on Instagram. The quantitative study focuses on brand attitude, purchase intention, and word-of-mouth (WOM) communication. Qualitative findings highlight food waste avoidance and economic savings as primary motivators. In the quantitative studies, guilty appeals shape brand attitude more effectively, while informational appeals increase purchase intention and positive WOM due to low brand familiarity. Despite existing literature suggesting significant impacts of influencer marketing, this study finds no significant differences in the influence of message source on brand attitude, purchase intention and WOM. This underscores the importance of tailoring message strategies to brand familiarity. The study also examines sustainability communication through the Elaboration Likelihood Model (ELM), revealing that a central route emphasizing detailed information aligns with effective strategies for promoting sustainable behavior. This dissertation provides insights into consumer motivations for reducing food waste and offers practical implications for businesses promoting suboptimal foods as a sustainable waste management solution.