Favoring plant instead of animal protein sources: Legitimation by authority, morality, rationality and story logic

A shift to a more healthy and sustainable diet (as recommended by the EAT Lancet Commission report) is currently hampered by persistent choices for meat, which are based on stable preferences and positive feedback mechanisms at the individual, social, and economic/organizational level. This paper puts forward the view that proposals for a diet shift will fall short without broad social legitimation, aimed at a change in social norms. That what previously belonged to the domain of morally acceptable practices (eating animal protein sources) has to be strongly limited, whereas what was previously not considered particularly noteworthy (eating plant protein sources) should become an accepted and, subsequently, a preferable alternative. This process of reordering has been set into motion by a typically expert-based legitimation, but the pace of its progress will depend on many other forces operating throughout society. Building on van Leeuwen's framework of persuasive strategies, this conceptual review paper aims to improve understanding of the various categories of legitimation, related to authority, moral evaluation, rationality, and story logic. Each category is examined with a view to how it may support (or oppose) the reordering of protein sources necessary for a diet shift. Key strategies are a further revision of the existing authority-based dietary guidelines, using the diversity of rationality-based legitimations to support them, avoiding polarization of moral-based ideologies and being cautious of myths, micro-myths and stories.