**Background:** To limit global warming to 1.5°C above pre-industrial levels, substantial reductions in greenhouse gas (GHG) emissions are necessary in a variety of sectors, one of them being the food system. Current diets, particularly those high in meat and other animal protein, and the production practices that support them are estimated to account for about one third of total GHG. On the demand-side, policies based on behavioural insights have been identified as a promising tool to promote more environmentally friendly food choices in general and reducing meat consumption in specific. Designing choice settings with so-called “green defaults” has been shown to be effective in various consumption contexts, robust across cultures and target groups, and highly accepted by consumer citizens. While the body of evidence and syntheses on behavioural interventions in general is growing, to the best of our knowledge, no comprehensive systematic review has been conducted to date that focuses on the effectiveness of defaults in the area of food consumption. The primary aim of the proposed research is therefore to compile the empirical evidence regarding whether and in which specific contexts which type of green defaults work that aim to reduce the GHG emissions resulting from meat consumption.
**Methods:** The systematic review will examine empirical studies that provide primary data on the implementation of defaults to reduce meat consumption. To identify relevant studies, we use the database of a prior systematic mapping study. We extend this database by updating the literature using pre-defined search strings in eleven bibliographic databases, Google Scholar, a theses repository, specialised academic journals, and specialist websites as well as conducting backward searches in the literature of review studies identified via search. Search results are screened for inclusion in a three-stage process at title, abstract, and full-text level in accordance to a set of predetermined inclusion and exclusion criteria. We critically appraise all studies included after full-text screening and exclude those of low quality. We extract descriptive and statistical information from all studies included after critical appraisal and account for their validity in the evidence synthesis.
Contact johanna.meier@rub.de for further details on the project.
