In recent years, a great deal of research has been conducted on consumers' attitudes and beliefs in favor and against alternative proteins (AP). By contrast, a much more limited research effort has been devoted to understanding stakeholders' point of view. The current work provides a first systematic review of the existing literature on stakeholders' beliefs towards alternative protein sources. Moreover, a secondary content analysis was carried out on the selected studies, providing an overview of the major themes emerging from the existing literature in relation to utilitarian, normative, and control beliefs that stakeholders hold towards AP. Results showed that stakeholders' beliefs are very different from those that emerged from previous research on consumers' views. Overall, stakeholders appear much more aware, compared to consumers, of the implications of using alternative proteins in relation to the main pillars of sustainability (economic, environmental, social). Stakeholders' beliefs were grouped into 13 categories, such as "economics", "consumers", and "rules". With respect to future scenarios, they attribute an important role to political institutions, with respect to both economic and communication aspects, which they consider crucial to overcome persistent consumer skepticism.
Keywords: cultured meat; edible insect; plant-based; rational action approach; sustainability; thematic analysis.