Reducing meat consumption: an experiment on insects, cultured meat, and plant-based alternatives
Global meat consumption is currently too high and is growing (Searchinger et al., 2014). Gram-for-gram meat, particularly red meat, is more harmful to planetary health than any other food that has been evaluated (Clark et al., 2019; Foley et al., 2011; IPCC, 2018). In addition to this, red meat increases the risk of mortality (Micha et al., 2012; Pan et al., 2011, 2012). In order to help people transition towards healthier and more sustainable diets, there is a clear need for meat alternatives. There are several key options that have not been embraced internationally: insects, cultured (lab-grown) meat, and plant-based meat alternatives. First, the recent EAT-Lancet report highlights that insects could be used as an alternate food source as a highly nutritious food with a relatively reduced impact on the environment (Willett et al., 2019). Second, cultured meat offers an alternative to meat that does not cause any harm to animals and with a reduced impact on the environment (Lynch & Pierrehumbert, 2019; Tuomisto & Teixeira de Mattos, 2011). Third, plant-based meat alternatives offer an option that is growing in popularity in countries such as the UK, again with a lower impact on the environment (Clark et al., 2019; Sabaté & Soret, 2014).
There is a growing evidence base that evaluates the public’s willingness to eat and potentially switch to these alternatives. However, these existing studies rely heavily on correlational analyses, and often from small, unrepresentative samples (Jensen & Lieberoth, 2019; Palmieri et al., 2019; Rumpold & Langen, 2019; Siegrist & Hartmann, 2020; Tan et al., 2016; Wassmann et al., 2021). These studies point to several factors that correlate with willingness to eat, including social norms and perceived sustainability. There is also some preliminary experimental evidence that social norm messages (Berger & Wyss, 2020) and environmental-benefit messages (Verneau et al., 2016) can increase willingness to eat insects. The current study aims to firstly replicate these initial findings in a larger sample, but then extend this work by determining if 1) these two interventions combine to yield greater effects, and 2) the findings extend to multiple meat alternatives: insects, cultured-meat, and plant-based meat alternatives.
The registration and statistical analysis plan will be uploaded to the Open Science Framework (OSF | Encouraging sustainable diets).
An online survey experiment in which participants are randomly allocated to 12 groups varying in the presentation of pro-meat alternative messages (i. control group, ii. evidence about the environmental benefits of meat alternatives, iii. message about social-norms, iv. evidence about environmental benefits + social norms message) and the type of meat alternative (i. insects, ii. cultured meat, iii. plant-based).
Group 1 (Control Group): No intervention.
Group 2 (Environmental benefits): A text-based intervention will be developed based on the latest evidence for the environmental costs (in terms of land use, emissions, water use, etc) of meat relative to the meat alternative.
Group 3 (Social norms): A text-based intervention will be developed building on existing social norm research. The intervention will describe a fictional UK survey which shows that a majority of the UK would be willing to try the meat alternatives.
Group 4 (Environmental benefits + Social norms): Interventions from Group 2 and 3 will be combined.
The primary outcome for this study will be willingness to eat meat alternatives. This will be the mean score from the willingness to eat three different products: insects, cultured meat, and plant-based alternatives. Willingness to eat each product will be measured using the single item “Are you willing to eat [meat alternative]?” (Adapted from: Siegrist & Hartmann, 2020) using a 7-point response scale (1 = Certainly not and 7 = Absolutely). An image of each product will be shown to participants when they rate it.
Secondary outcomes include willingness to eat meat alternatives as a replacement for meat: “‘I would be prepared to eat [meat alternative] as a substitute for meat’’ (Verbeke, 2015), measured on a 7-point response scale (1 = Completely disagree and 7= Completely Agree) and perceived taste of meat alternatives “How tasty do you think this [meat alternative] would be?” (Tan et al., 2016) also measured on a 7-point response scale (1 = Not at all tasty, 7 = Extremely tasty).
Other outcomes will include dietary characteristics (e.g., vegetarian/carnivore).
Nine meat alternatives will be selected for the current study; three from each category. The selection was based on the main options proposed for mainstream consumption from researchers and those in the food industry.
- Bug burger
- Crunchy cricket “chicken” nuggets
- Maggot sausages
- Cultured beef burger
- Cultured chicken nuggets
- Cultured pork sausage
- Impossible brand plant burger
- Quorn brand “chicken” pieces
- Linda mccartney brand vegetarian sausages
Pilot study: A pilot study (n = 100) will be used to determine that the primary and secondary outcomes have high internal consistency (defined as α > .80). If this criterion is not met, then a follow up pilot study (also n = 100) will be conducted.
Main study: We will recruit 1356 participants nationally representative of the UK population from Prolific Academic. The sample size calculation was based on: d = .18, α = 0.05, power = .80, design = 4x3 ANOVA. See R code in the OSF folder for the sample size calculation and justification.
Replication study: We will then conduct a replication study using the same methods in a different country, recruiting 1356 participants, nationally representative of the USA population from Prolific Academic.
We will finally conduct an internal meta-analysis of the two samples.
n = 100
Estimated time: 5 minutes
Pilot study 2:
n = 100
Estimated time: 5 minutes
n = 1356
population: nationally representative UK
Estimated time: 10 minutes
n = 1356
population: nationally representative USA
Estimated time: 10 minutes
Total cost: £4922.40
The data, code, and study materials will be uploaded to the OSF upon submission to an open access journal and the manuscript will be uploaded as a preprint to psyarxiv.com.
Berger, S., & Wyss, A. M. (2020). Consumers’ Willingness to Consume Insect-Based Protein Depends on Descriptive Social Norms. Frontiers in Sustainable Food Systems, 4. https://doi.org/10.3389/fsufs.2020.00144
Clark, M. A., Springmann, M., Hill, J., & Tilman, D. (2019). Multiple health and environmental impacts of foods. Proceedings of the National Academy of Sciences, 201906908. https://doi.org/10.1073/pnas.1906908116
de Groot, J. I. M., & Schuitema, G. (2012). How to make the unpopular popular? Policy characteristics, social norms and the acceptability of environmental policies. Environmental Science & Policy, 19–20, 100–107. https://doi.org/10.1016/j.envsci.2012.03.004
Foley, J. A., Ramankutty, N., Brauman, K. A., Cassidy, E. S., Gerber, J. S., Johnston, M., Mueller, N. D., O’Connell, C., Ray, D. K., West, P. C., Balzer, C., Bennett, E. M., Carpenter, S. R., Hill, J., Monfreda, C., Polasky, S., Rockström, J., Sheehan, J., Siebert, S., … Zaks, D. P. M. (2011). Solutions for a cultivated planet. Nature, 478(7369), 337–342. https://doi.org/10.1038/nature10452
IPCC. (2018). Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty.
Jensen, N. H., & Lieberoth, A. (2019). We will eat disgusting foods together – Evidence of the normative basis of Western entomophagy-disgust from an insect tasting. Food Quality and Preference, 72, 109–115. https://doi.org/10.1016/j.foodqual.2018.08.012
Lynch, J., & Pierrehumbert, R. (2019). Climate Impacts of Cultured Meat and Beef Cattle. Frontiers in Sustainable Food Systems, 3. https://doi.org/10.3389/fsufs.2019.00005
Micha, R., Michas, G., & Mozaffarian, D. (2012). Unprocessed red and processed meats and risk of coronary artery disease and type 2 diabetes—An updated review of the evidence. Curr Atheroscler Rep, 14(6), 515–524. https://doi.org/10.1007/s11883-012-0282-8
Palmieri, N., Perito, M. A., Macrì, M. C., & Lupi, C. (2019). Exploring consumers’ willingness to eat insects in Italy. British Food Journal. https://doi.org/10.1108/BFJ-03-2019-0170
Pan, A., Sun, Q., Bernstein, A. M., Schulze, M. B., Manson, J. E., Stampfer, M. J., Willett, W. C., & Hu, F. B. (2012). Red meat consumption and mortality: Results from 2 prospective cohort studies. Arch Intern Med, 172(7), 555–563. https://doi.org/10.1001/archinternmed.2011.2287
Pan, A., Sun, Q., Bernstein, A. M., Schulze, M. B., Manson, J. E., Willett, W. C., & Hu, F. B. (2011). Red meat consumption and risk of type 2 diabetes: 3 cohorts of US adults and an updated meta-analysis. Am J Clin Nutr, 94(4), 1088–1096. https://doi.org/10.3945/ajcn.111.018978
Rumpold, B. A., & Langen, N. (2019). Potential of enhancing consumer acceptance of edible insects via information. Journal of Insects as Food and Feed, 5(1), 45–53. https://doi.org/10.3920/JIFF2018.0041
Sabaté, J., & Soret, S. (2014). Sustainability of plant-based diets: Back to the future. The American Journal of Clinical Nutrition, 100(suppl_1), 476S-482S. https://doi.org/10.3945/ajcn.113.071522
Searchinger, T. (World R. I. U., Hanson, C. (World R. I., Ranganathan, J. (World R. I., Lipinski, B. (World R. I., Waite, R. (World R. I., Winterbottom, R. (World R. I., Dinshaw, A. (World R. I., Heimlich, R. (World R. I., Boval, M. (INRA, Chemineau, P. (INRA, Dumas, P. (Centre de C. I. en R. A. pour le D., Guyomard, H. (INRA, Kaushik, S. (INRA, Markovsky, D. (Centre de C. I. en R. A. pour le D. ), Manceron, S. (INRA, & Ben Ari, T. (INRA. (2014). Creating a sustainable food future. A menu of solutions to sustainably feed more than 9 billion people by 2050. World resources report 2013-14: Interim findings. World Resources Institute. Creating a sustainable food future. A menu of solutions to sustainably feed more than 9 billion people by 2050. World resources report 2013-14 : interim findings
Siegrist, M., & Hartmann, C. (2020). Perceived naturalness, disgust, trust and food neophobia as predictors of cultured meat acceptance in ten countries. Appetite, 155, 104814. https://doi.org/10.1016/j.appet.2020.104814
Tan, H. S. G., Fischer, A. R. H., van Trijp, H. C. M., & Stieger, M. (2016). Tasty but nasty? Exploring the role of sensory-liking and food appropriateness in the willingness to eat unusual novel foods like insects. Food Quality and Preference, 48, 293–302. https://doi.org/10.1016/j.foodqual.2015.11.001
Tuomisto, H. L., & Teixeira de Mattos, M. J. (2011). Environmental Impacts of Cultured Meat Production. Environmental Science & Technology, 45(14), 6117–6123. https://doi.org/10.1021/es200130u
Verbeke, W. (2015). Profiling consumers who are ready to adopt insects as a meat substitute in a Western society. Food Quality and Preference, 39, 147–155. https://doi.org/10.1016/j.foodqual.2014.07.008
Verneau, F., La Barbera, F., Kolle, S., Amato, M., Del Giudice, T., & Grunert, K. (2016). The effect of communication and implicit associations on consuming insects: An experiment in Denmark and Italy. Appetite, 106, 30–36. https://doi.org/10.1016/j.appet.2016.02.006
Wassmann, B., Siegrist, M., & Hartmann, C. (2021). Correlates of the willingness to consume insects: A meta-analysis. Journal of Insects as Food and Feed, 1–14. https://doi.org/10.3920/JIFF2020.0130