Interventions that Influence Animal-Product Consumption: A Meta-Review

Abstract

Transitioning toward more plant-based diets can alleviate health and sustainability challenges. However, research on interventions that influence animal-product consumption remains fragmented and inaccessible to researchers and practitioners. We conducted an overview of systematic reviews, also known as a meta-review. We searched five databases for reviews that examined interventions that influence (increase or decrease) the consumption of animal products. We quantitatively summarised results using individual studies' directions of effect because reviews rarely reported effect sizes of primary studies. We also discussed the contexts in which the evidence for interventions appeared strongest in light of the broader literature on behaviour change. Eighteen systematic reviews met inclusion criteria, 12 of which examined interventions intended to decrease animal-product consumption and 6 of which examined interventions intended to increase animal-product consumption. In total, only two reviews conducted quantitative meta-analyses. Across all reviews, vote counting based on the direction of individual studies’ estimates indicated that providing information on the environmental impact of meat consumption may reduce consumption, with 10 of 11 estimates suggesting reduced consumption (91% [95% CI 62.3%, 98.4%]; p = .012). Providing information on the health consequences of meat consumption, emphasising social norms, and reducing meat portion sizes also appeared promising, albeit with more limited strength of evidence. Reviews examining interventions that decreased consumption predominately focused on meat (10/12 reviews). Future reviews should conduct quantitative syntheses where appropriate and could more frequently examine interventions that influence the consumption of animal products other than meat.

Effects of experimentally induced self-affirmation on the openness to meat reduction and alternative protein sources

“…Previous studies demonstrate that it is possible to experimentally affect meat consumption, at least in the short term (Cordts et al, 2014;Kunst and Hohle, 2016;Carfora et al, 2017Carfora et al, , 2019Amiot et al, 2018;Dowsett et al, 2018; for meta-analyzes see Grundy et al, 2021;Kwasny et al, 2022). It appears from a review of the interventions that shortterm outcomes, such as the immediate choice of foods, could be more amenable to change than more general habits and attitudes (Dowsett et al, 2018).…”

“…Also, matching messages with the needs of consumers (e.g., their values or decision stages) increases their effectiveness (Kwasny et al, 2022). Finally, contextual factors, such as nudging or enhancing the visibility/ availability of vegetarian options, have proven helpful in encouraging meat-free options (Grundy et al, 2021;Kwasny et al, 2022).…”

The Effects of Exposure to Information About Animal Welfare Reforms on Animal Farming Opposition: A Randomized Experiment

“…There are theoretical reasons to expect that individuals will seek to conform to perceived social norms (e.g., Cialdini & Trost 1998), including in their attitudes and behaviors towards farmed animals (Delon, 2018). Some studies provide evidence that emphasizing information about people's attitudes and behaviors towards animals and how this is changing over time can affect the audience's own attitudes and behavior (e.g., Sparkman & Walton, 2017;Grundy et al, 2021).…”

“…Caldwell's (2016) experiment found that participants who read articles about animal welfare changes "were more likely to intend to reduce their consumption of animal products than participants who read the control articles." More broadly, Mathur et al's (2021) meta-analysis found that providing information about farmed animals or their welfare appeared to consistently reduce reported meat consumption or consumption intentions. However, it is unclear whether animal welfare reforms also affect willingness to support further institutional changes (i.e.…”

Effects of public policy interventions for environmentally sustainable food consumption: a systematic map of available evidence

“…Numerous reviews have explored various measures and policies to promote dietary changes and reduce food waste, but these reviews have limitations in their scope and focus. Some concentrate exclusively on reducing consumption of animal-source foods [24,30], while others examine interventions that aim to induce behaviour changes, without considering environmental impact [21,22,25,31]. Some reviews focus solely on specific types of policies or outcomes, such as digital behavioural interventions [31], climate change mitigation [32,33], food waste reduction [32] or health [20,24,34].…”