International Journal of Environmental Research and Public Health Review People’s Values and Preferences about Meat Consumption in View of the Potential Environmental Impacts of Meat: A Mixed-methods Systematic Review Claudia Valli 1,2,3, * , Małgorzata Maraj 4 , Anna Prokop-Dorner 5 , Chrysoula Kaloteraki 3 , Corinna Steiner 3 , Montserrat Rabassa 3 , Ivan Solà 3,6 , Joanna Zajac 4 , Bradley C. Johnston 7,8 , Gordon H. Guyatt 9 , Malgorzata M. Bala 4 and Pablo Alonso-Coello 3,6 1 Department of Paediatrics, Obstetrics, Gynaecology and Preventive Medicine, Universidad Autónoma de Barcelona, 08193 Barcelona, Spain 2 Avedis Donabedian Research Institute (FAD), 08037 Barcelona, Spain 3 Iberoamerican Cochrane Centre, Biomedical Research Institute San Pau (IIB Sant Pau), 08025 Barcelona, Spain 4 Chair of Epidemiology and Preventive Medicine, Department of Hygiene and Dietetics, Jagiellonian University Medical College, 31-034 Krakow, Poland 5 Chair of Epidemiology and Preventive Medicine, Department of Medical Sociology, Jagiellonian University Medical College, 31-034 Krakow, Poland 6 CIBER de Epidemiología y Salud Pública (CIBERESP), 28029 Madrid, Spain 7 Department of Nutrition, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX 77843, USA 8 Department of Epidemiology and Biostatistics, School of Public Health, Texas A&M University, College Station, TX 77843, USA 9 Department of Medicine, McMaster University, Hamilton, ON L8N 3Z5, Canada * Correspondence: claudia.valli89@gmail.com Abstract: Background: Health is not the only aspect people consider when choosing to consume meat; Citation: Valli, C.; Maraj, M.; environmental concerns about the impact of meat (production and distribution) can influence people’s Prokop-Dorner, A.; Kaloteraki, C.; meat choices. Methods: We conducted a mixed-methods systematic review, searched six databases Steiner, C.; Rabassa, M.; Solà, I.; Zajac, from inception to June 2020, and synthesised our findings into narrative forms. We integrated the J.; Johnston, B.C.; Guyatt, G.H.; et al. evidence from quantitative and qualitative data sets into joint displays and assessed the confidence People’s Values and Preferences about Meat Consumption in View of in the evidence for each review finding following the GRADE-CERQual approach. Results: Of the the Potential Environmental Impacts 23,531 initial records, we included 70 studies: 56 quantitative, 12 qualitative, and 2 mixed-methods of Meat: A Mixed-methods studies. We identified four main themes: (1) reasons for eating meat; (2) reasons for avoiding meat; Systematic Review. Int. J. Environ. (3) willingness to change meat consumption; and (4) willingness to pay more for environmentally Res. Public Health 2023, 20, 286. friendly meat. The overall confidence was low for the reasons for eating and/or buying meat, for https://doi.org/10.3390/ avoiding meat, and for willingness to change meat consumption, and was moderate for willingness ijerph20010286 to pay more for environmentally friendly meat. Conclusions: Regardless of people’s general beliefs Academic Editor: Gilbert Ramirez about meat and its impact on the environment, most people may be unwilling to change their meat consumption. Future research should address the current limitations of the research evidence to Received: 8 November 2022 assess whether people are willing to make a change when properly informed. Revised: 14 December 2022 Accepted: 15 December 2022 Keywords: food preferences; consumer behaviour; meat consumption; environmental concerns; Published: 24 December 2022 values and preferences; mixed methods; systematic review Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. 1. Introduction This article is an open access article Besides the availability of and access to food, individuals’ food choices are influenced distributed under the terms and by a wide range of factors [1], including biological, psychological, social, cultural, and conditions of the Creative Commons historical influences [2]. These factors can be unconscious while others are more rational [2]. Attribution (CC BY) license (https:// For example, many people consider meat a healthy food and an important source of creativecommons.org/licenses/by/ nutrients that must be part of their diet, whereas other people avoid or limit their meat 4.0/). Int. J. Environ. Res. Public Health 2023, 20, 286. https://doi.org/10.3390/ijerph20010286 https://www.mdpi.com/journal/ijerph Int. J. Environ. Res. Public Health 2023, 20, 286 2 of 25 intake because they believe that meat is harmful given its alleged association with chronic diseases such as cancer [3]. Health, however, is not the only aspect people consider when choosing to consume meat; other factors such as concern for animal welfare and the environmental impact of meat (production and distribution) can influence people’s meat choices and thus its consumption [4]. If one believes that guidelines should reflect people’s values and preferences (rather than prescribing what a panel thinks people should do according to the panel’s values and preferences), understanding people’s overall meat values and preferences becomes crucial for producing trustworthy nutritional recommendations [5,6]. However, many dietary guidelines, including meat recommendations, do not explicitly address their target population’s values and preferences on meat intake [5,7,8]. Previously, as part of the NutriRECS initiative (www.nutrirecs.com (accessed on 17 March 2020)), we published a systematic review specifically addressing the health- related values and preferences regarding meat consumption [3]. The evidence informed the recommendations for unprocessed red meat and processed meat intake [9]. Cognizant of the increasing evidence suggesting that large-scale meat production facilities, by depleting the availability of fresh water and as a major source of anthropogenic greenhouse gas emissions, are a substantive driver for global warming and environmental degradation, some people have limited their meat consumption as a result of these environmental concerns [10–12]. We have therefore conducted a systematic review to evaluate how environmental concerns may influence meat consumption behaviours. 2. Methods We conducted a systematic review according to a protocol registered in PROSPERO (CRD42018088854) [13] and adhered to the PRISMA (Preferred Reporting Items for System- atic Reviews and Meta-Analyses) reporting statement [14]. 2.1. Data Sources and Searches We designed and conducted an exhaustive search in MEDLINE (via PubMed), EM- BASE (via Ovid), Web of Science (Institute for Scientific Information), CAB abstracts (via CABI; Centre for Agriculture and Bioscience), AGRIS (International System for Agricul- tural Science and Technology), and FSTA (Food Science and Technology Abstracts) from inception to June 2020. We defined search terms related to meat consumption; consumer behaviour; and values, preferences, and attitudes and combined them with relevant terms from the controlled vocabulary from each database. We did not restrict our search by publication status or date of publication (Table S1). We also reviewed reference lists of the included articles and relevant systematic reviews. 2.2. Study Selection We included studies exploring how environmental values and preferences can in- fluence meat consumption in adults (≥80% of the sample were 18 years or older). If studies did not report the participants’ age, we assumed that >80% of the participants were ≥18 years old. We included studies that obtained data by qualitative (e.g., inter- views, focus groups), quantitative (e.g., cross-sectional survey), or mixed methods (e.g., both interviews or focus groups and a cross-sectional survey). We included only studies published from 2000 onwards conducted in Europe, Australia, Canada, and the United States (USA) because we considered them a homogeneous set of countries reflecting similar socio-economic characteristics and values. If a study was conducted in multiple countries, including countries that did not fulfil the eligibility criteria, it was included. We excluded experimental/intervention studies and studies focusing on: meat alternatives (e.g., cultured meat, in vitro meat, functional meat products, or genetically modified meat); meat quality (meat composition, sensory quality, and/or palatability factors or origin of meat); meat safety (e.g., food handling, chemical hazards/meat contamination, or storing/preservation of meat); meat industry (e.g., market research to inform or meet consumers’ demands); meat Int. J. Environ. Res. Public Health 2023, 20, 286 3 of 25 consumption trends; and studies focusing on specific populations (e.g., cancer survivors or pregnant women). Following a calibration exercise, teams of two reviewers independently screened the titles and abstracts of all retrieved references from the search. Subsequently, teams of two reviewers independently reviewed the full text of articles deemed potentially eligible in the title and abstract screening. In case of disagreement, reviewers reached consensus with the help of a third reviewer. 2.3. Data Extraction We used two ad hoc data extraction forms for quantitative and qualitative studies (Tables S2 and S3). For mixed-methods studies, the quantitative and qualitative evidence was extracted separately in the corresponding extraction form. After calibration, two reviewers independently abstracted information from each study including: (1) study identification; (2) objectives or research questions; (3) participant characteristics; (4) general design and methods; (5) risk of bias/methodological limitations; and (6) findings. In case of disagreement, reviewers reached consensus with assistance from a third reviewer. 2.4. Risk-of-Bias/Methodological Limitations Assessment For quantitative studies, we used an adapted version of available GRADE guidance to assess the risk of bias (RoB) of studies on the importance of outcomes on values and preferences [15]. We considered five items grouped in three domains: (1) selection of participants; (2) missing outcome data; and (3) the measurement instruments’ validity. We rated studies as high risk of bias if the measurement instrument did not have evidence of validity, or it was unclear, and as moderate risk if it was validated but two or more items proved at high risk of bias. For qualitative studies, we used the Critical Appraisal Skills Programme (CASP) qualitative research checklist to assess the methodological limitations (ML) of the studies, consisting of the appropriateness of the following items: (1) aim of the research; (2) qual- itative methodology; (3) research design; (4) recruitment strategy; (5) data collection; (6) researcher and participants relationship; (7) ethical issues; (8) data analysis; (9) summary of findings; and (10) value of the research [16]. We rated studies as “serious methodological limitations” if three or more items had serious concerns, as “Moderate methodological limitations” if they had two items with serious concerns, “minor methodological limita- tions” if one item had serious concerns, and “No or minor concerns” if no items had serious concerns. A pair of reviewers independently assessed RoB/methodological limitations; in case of disagreement, they reached consensus with the help of a third senior methodologist. For mixed-methods studies, we used the mixed methods appraisal tool (MMTA) consisting of the appropriateness of the five following items: (1) use of mixed-methods design, (2) integration of different components of the study, (3) interpretation of qualitative and quantitative components, (4) reporting of inconsistencies between quantitative and qualitative results, and (5) quality criteria of quantitative and qualitative evidence [17]. 2.5. Data Synthesis and Analysis We synthesised our findings into narrative forms following an iterative four-step ap- proach that involved simultaneous quantitative and qualitative data collection and analysis. First, we selected two to three eligible articles per study design, identified key themes, and coded them in different categories. Second, we used these categories to design ad hoc data extraction forms. Third, through an iterative process, we compared the key themes of the different categories identified across all studies, categorised them into different groups depending on the type of population (e.g., women, vegetarians, elderly) and developed analytic themes. Finally, we applied a critical meta-narrative synthesis to transform the quantitative data into qualitative data [18–20]. For the latter, we used four systematic profiles and several critical questions (e.g., “Modal profile” refers to the most occurring different attributes, and therefore if most study participants reported to consume meat, Int. J. Environ. Res. Public Health 2023, 20, 286 4 of 25 they were described as omnivores) to extract the identified narratives and to guide our synthesis of data (Table S4) [18]. We synthesised and narratively reported the findings according to the identified themes. Within each identified theme, we divided the findings into different subsections (if applicable) according to the following criteria: 1. Type of data: whether the findings were from quantitative (e.g., questionnaire) or qualitative (e.g., interview) data sets. 2. Previous knowledge/information on the environmental impact of meat: whether the participants had been informed about the environmental impact of meat before being asked about their beliefs, preferences, and/or behaviours. 2.6. Integrating Qualitative and Quantitative Analyses We compared the narratively reported findings from the quantitative and qualita- tive data sets, searching for similarities and differences [21]. We integrated them into joint displays, which present findings from both quantitative and qualitative data sets per theme [21–23], and assessed whether findings from each data set agreed, offered complementary information, or contradicted each other [22]. 2.7. Confidence in the Evidence We assessed the confidence in the integrated evidence using the GRADE-CERQual approach [24]. This is the most appropriate approach for assessing the extent to which a review finding is a reasonable representation of the phenomenon of interest—in our case the phenomenon of interest was people’s values and preferences regarding meat consumption related to environmental impact. Therefore, we assessed the confidence in the evidence considering the following GRADE-CERQual domains: methodological limitations, relevance, coherence, and adequacy, with the exception that we used different appraisal tools for the risk of bias or methodological limitations depending on whether the evidence was quantitative or qualitative as explained above. To increase consistency and transparency in the overall assessment, we assigned a number value to each of the GRADE-CERQual levels of the concerns as follows: no or very minor concerns were valued as 0; minor concerns as 1; moderate concerns as 2 and; serious concerns as 3. Based on the sum of values per domain and per theme, we judged the overall confidence for all the identified themes as: high confidence (values between 0 and 1); moderate confidence (values between 2 and 4); low confidence (values between 5 and 8); and very low confidence (values between 9 and 12). 3. Results 3.1. Study Selection We retrieved 23,531 articles. After title and abstract screening, 429 were poten- tially eligible. We excluded 359 studies (Table S5). After full-text screening, we in- cluded 56 quantitative [25–78], 12 qualitative [79–90], and 2 mixed-methods studies [91,92]. Figure 1 presents the flow diagram with the search results and the selection of studies. 3.2. Study Characteristics Of the 56 quantitative studies, 31were conducted in Europe, 11 in the United States, 4 in the United Kingdom, 4 in multiple countries, 4 in Australia, 1 in New Zealand, and 1 study did not specify where it was conducted. Forty-five studies were conducted between 2010 and 2020, and fifteen were conducted between 2000 and 2010. The number of participants ranged between 82 and 24,340. Of the 12 qualitative studies, 4 were conducted in Europe, 3 in the United States, 2 in Australia, 2 were conducted in multiple countries, and 1 in the United Kingdom. Ten studies were conducted between 2011 and 2019, whereas two studies were conducted before 2010 (one in 2005 and the other in 2008). The number of participants ranged between 19 and 270. The two mixed-methods studies were conducted in Europe in 2018 and 2019 and included between 42 and 1532 participants. Table 1 presents the Int. J. Environ. Res. Public Health 2022, 19, x 5 of 25 Int. J. Environ. Res. Public Health 2023, 20, 286 5 of 25 characteristics of the 73 included studies. The risk-of-bias and methodological limitation assessment of the included studies is reported in Table S6–S8. Figure 1. Flow diagram with the search results and selection of studies. Figure 1. Flow diagram with the search results and selection of studies. 3.2. Study characteristics Of the 60 quantitative studies, 37 were conducted in Europe, 12 in the United States, 4 in the United Kingdom, 4 in Australia, 1 in New Zealand, 1 in multiple countries, and 1 study did not specify where it was conducted. Forty-five studies were conducted between 2010 and 2020, and fifteen were conducted between 2000 and 2010. The number of partic- ipants ranged between 82 and 24,340. Of the 12 qualitative studies, 4 were conducted in Europe, 3 in the United Kingdom, 2 in Australia, 2 were conducted in multiple countries, and 1 in the United States. Ten studies were conducted between 2011 and 2019, whereas Int. J. Environ. Res. Public Health 2023, 20, 286 6 of 25 Table 1. Study characteristics. Type of Data Collection Included Gender (% Study Id * Primary Focus Country Sampling Study Methods Participants Female) To investigate substitution and complementary effects of beef mince attributes (with a focus on labels of Low, Moderate, High Fat, Local, National, Imported, Akaichi 2020 Organic, Low, Moderate, and UK and Spain QUANT Questionnaire Quota 2417 60 [74] High Greenhouse Gas Emissions) on consumers’ preferences and willingness to pay for the product, drawing on data from large choice experiments conducted in the UK and Spain. To compare and contrast the importance of the seven Questionnaire Apostolidis sustainability-related labels for UK QUANT administered face Convenience 600 65 2019 [25] three consumer groups (meat to face eaters, meat reducers, and vegetarians). To identify dietary patterns and their associated GHG emissions, then to explore their relationship, Asvatourian Postal survey as domain-specific behavioural South West Scotland QUANT Random 422 32 2018 [60] questionnaire patterns, with measures of environmental attitudes and behaviours. To investigate UK meat-eaters’ Bryant 2019 views of various aspects of United Kingdom QUANT Questionnaire Convenience 1000 50 [61] vegetarianism and veganism. To investigate consumers’ self-reported red and processed meat consumption (from intake Clonan 2015 Postal survey and purchasing data) UK QUANT Random 842 60 [62] questionnaire against/towards animal welfare, human health, and environmental sustainability. To determine the effect of information regarding the negative attributes of meat consumption on demand for Cordts 2014 Online survey meat in Germany, with the focus Germany QUANT Quota 590 48 [33] questionnaire on four particular attributes: animal welfare, human health, personal image, and climate change. To investigate the fundamental Crnic 2013 [34] Slovenia QUANT Questionnaire Random NR NR characteristics of vegetarianism. To investigate consumers’ de Boer 2013 Online survey behaviours towards meat Netherlands QUANT Stratified 1083 50 [63] questionnaire consumption and climate change. To assess how consumers evaluate the mitigation effectiveness of the food-related and the energy-related options, de Boer 2016 Online survey particularly whether they Netherlands QUANT Quota 527 50 [64] questionnaire recognise the crucial differences between the less meat option, the local food option, and the organic food option. EU countries (Portugal; Spain; Malta; Slovenia; To assess how responses to the Greece; Cyprus; options for pro-environmental Hungary; Bulgaria; protein consumption (plant Romania; Latvia; based or animal based) might be Lithuania; Estonia; shaped by cultural, culinary, and Poland; Slovakia; de Boer 2018 economic spatial gradients Czech Republic; Italy; QUANT Telephone survey Random 24340 NR [65] (including GDP per capita) at the France; Ireland; regional level and differences in United Kingdom; environmentally friendly Netherlands; behaviour and gender at the Belgium; individual level. Luxembourg; Germany; Austria; Finland; Sweden; Denmark) Int. J. Environ. Res. Public Health 2023, 20, 286 7 of 25 Table 1. Cont. Type of Data Collection Included Gender (% Study Id * Primary Focus Country Sampling Study Methods Participants Female) To identify different dietary types which might constitute degrees of transition to low-meat diets (omnivores, pro-flexitarians, de Gavelle flexitarians, vegetarians), to Online survey France QUANT Quota 2055 52 2019 [36] characterise how these diets questionnaire differ in terms of protein source intake, and to determine whether attitudes and beliefs might explain these dietary types. To examine associations between the support and variables related to meat curtailment and to De Groeve Online survey examine the effect of providing Belgium QUANT Convenience 429 54 2017 [66] questionnaire information about the climate impact of meat on the support for the less meat initiatives (LMIs). To investigate the motives underlying the different forms of DeBacker 2014 vegetarianism and Online survey Flanders, Belgium QUANT Convenience 1556 NR [35] semi-vegetarianism in a culture questionnaire where meat continues to play a crucial role in people’s diets. To explore the main reasons for adopting and maintaining a vegan lifestyle among a heterogenous group of vegans from different U.S. states; and to Postal survey Dyett 2013 [37] USA QUANT Convenience 100 76 determine whether participants’ questionnaire diet and lifestyle choices coincided with positive health indices and selected outcome assessment. To obtain information on the consumer decision-making process for beef, in order to determine the relative Eldesouky Online survey Random importance of sustainability Spain QUANT 285 51 2020 [26] questionnaire stratified claims and traditional attributes, and to identify consumer profiles with similar perceptions and intentions. To investigate consumers’ perceptions and attitudes Frewer 2005 Online survey towards animal welfare issues Netherlands QUANT Convenience 1000 NR [27] questionnaire related to animal husbandry and environmental impact. To examine perceived Ginn 2019 effectiveness of meat reduction as United States QUANT Questionnaire Convenience 527 60 (Study 1) [67] a climate change mitigation strategy. To examine whether people responded differently to brief messages about meat’s impact Ginn 2019 than to messages about more United States QUANT Questionnaire Convenience 275 52 (Study 2) [67] traditionally accepted strategies for mitigating climate change (e.g., driving less). First, to analyse which production attributes related to environment, health, and animal welfare are ranked highest by consumers when making choices about purchases of pork in Grunert 2018 Germany and Poland. Second, to Online survey Germany; Poland QUANT Convenience 2005 48 [28] investigate how those production questionnaire attributes that are regarded as important by consumers are traded off against conventional product attributes (fat content, colour, origin) and price in a choice experiment. Int. J. Environ. Res. Public Health 2023, 20, 286 8 of 25 Table 1. Cont. Type of Data Collection Included Gender (% Study Id * Primary Focus Country Sampling Study Methods Participants Female) To compare consumer groups with different self-declared diet styles regarding meat Hagmann (vegetarians/vegans, Paper-based Switzerland QUANT Random 4213 47 2019 [38] pescatarians, low- and regular questionnaire meat consumers) in terms of their motives, protein consumption, diet quality, and weight status. To examine participants’ reasons for limiting animal products as well as factors related to stability or disruption of participant Snowball Haverstock animal product limitation. To Online survey USA QUANT and con- 247 85 2012 [39] focus on differences and questionnaire venience similarities between current and former animal product limiters (pescatarians, vegetarians, vegans). To examine the relationships between a moral emotion (i.e., Herzog 2009 sensitivity to visceral disgust) Online survey USA QUANT Convenience 424 67 [40] and animal activism, attitudes questionnaire toward animal welfare, and consumption of meat. To examine the differences between health-oriented and ethical-oriented vegetarians by Hoffman 2013 Online survey comparing conviction, nutrition USA QUANT Convenience 312 85 [41] questionnaire knowledge, dietary restriction, and years as vegetarian between the two groups. To evaluate the structure of common motives for a vegetarian diet, to use that measure to develop behavioural and Hopwood psychological profiles of people United States QUANT Questionnaire Convenience 7488 57 2020 [42] who would be most likely to adopt a plant-based diet for different reasons, and to examine whether this profile predicts responses to advocacy materials. To explore fear using protection motivation theory to measure how individuals appraise and cope with the threat of climate Hunter 2016 Postal survey change consequences in the food Sweden QUANT Random 219 45 [68] questionnaire mitigation context in order to understand factors which motivate consumers to reduce or alter their meat consumption. 11 Eurasian countries: China, Czech To determine the relationship Republic, Great between the consumption of Izmirli 2011 Britain, Iran, Ireland, Online survey animal products and attitudes QUANT Convenience 3.433 NR [43] South Korea, questionnaire towards animals among Macedonia, Norway, university students in Eurasia. Serbia, Spain, and Sweden To analyse the determinants that Kayser 2013 play a role in the differences in Online survey Germany QUANT Quota 956 51 [44] meat consumption patterns in questionnaire Germany. To provide information on the relative preferences of consumers for minced meat attributes and Koistinen 2013 examine whether meat type, Online survey Finland QUANT Purposive 1.623 50 [29] method of production, fat questionnaire content, price, and presence of carbon footprint information have impact on consumer choice. Int. J. Environ. Res. Public Health 2023, 20, 286 9 of 25 Table 1. Cont. Type of Data Collection Included Gender (% Study Id * Primary Focus Country Sampling Study Methods Participants Female) To examine changes in meat consumption among Finnish Latvala 2012 consumers, taking into account Online survey Finland QUANT Purposive 1623 50 [69] both stated past changes and questionnaire intended future changes. Reasons for change were also identified. The aim of this study was to examine consumers’ perceived Lea 2003 [45] South Australia QUANT Questionnaire Random 601 57 benefits and barriers to the consumption of a vegetarian diet. To determine the proportion of Partly non-vegetarians with similar random Postal survey Lea 2004 [46] beliefs as vegetarians and to Australia QUANT and partly 707 56 questionnaire examine their personal nonran- characteristics. dom To examine Australians’ Postal survey Lea 2008 [70] food-related environmental Australia QUANT Random 223 52 questionnaire beliefs and behaviours. To explore the understanding of meat consumption and potential drivers for its reduction in New Online survey Lentz 2018 [47] Zealand. The study investigated New Zealand QUANT Random 841 50 questionnaire consumers’ attitudes, motivations, and behaviours in regard to meat consumption. To examine whether abstract values are related to concrete Food Choice Motives (FCMs), whether these Food Choice Lindeman Ideologies (FCIs) are related to a Paper-based 2001 (Study 1) Finland QUANT Convenience 82 100 humanist or a normative view of questionnaire [48] the world, and whether various dietary groups (e.g., vegetarians and omnivores) endorse these FCIs in different ways. To examine whether abstract values are related to concrete Food Choice Motives (FCMs), whether these Food Choice Lindeman Ideologies (FCIs) are related to a Paper-based 2001 (Study 2) Finland QUANT Convenience 149 100 humanist or a normative view of questionnaire [48] the world, and whether various dietary groups (e.g., vegetarians and omnivores) endorse these FCIs in different ways. To examine how young adults in Finland perceive barriers to Mäkiniemi Paper-based climate-friendly food choices and Finland QUANT Convenience 350 80 2014 [71] questionnaire how these barriers are associated with their choices. To identify consumer segments with varying levels of willingness to make the following changes to their protein consumption: Panel Malek 2019 reduce meat consumption, follow Online survey provider/quota Australia QUANT 287 53 [72] a meat-free diet most of the time, questionnaire sam- avoid meat consumption pling? altogether, and follow a strict plant-based diet (i.e., stop eating all animal products). To examine consumer McCarthy perceptions towards beef and the Ireland QUANT Questionnaire Random 218 NR 2003 [30] influence of these perceptions on consumption. To investigate Irish consumers’ McCarthy Questionnaire on a beliefs about pork and poultry Ireland QUANT Random 257 87 2004 [31] ‘door to door’ basis consumption. Int. J. Environ. Res. Public Health 2023, 20, 286 10 of 25 Table 1. Cont. Type of Data Collection Included Gender (% Study Id * Primary Focus Country Sampling Study Methods Participants Female) To investigate the attitudes and beliefs about vegetarianism and Mullee 2017 meat consumption among the Online survey Belgium QUANT Random 2.436 49 [49] Belgian population to better questionnaire understand motivations underlying these behaviours. To learn about what is eaten in meatless meals and attitudes and perceptions towards meat reduction, and to build upon and Online survey Neff 2017 [50] USA QUANT Convenience 1112 51 add depth to previous research questionnaire on meat-reduction behaviours in the USA and other high-meat-consuming countries. To investigate the sociodemographic profiles of individuals reporting health and Peneau 2017 environmental dilemmas when Online survey France QUANT Convenience 22,935 75 [32] purchasing meat, fish, and dairy questionnaire products, and to compare diet quality of individuals with and without dilemmas. 11 Eurasian countries: To examine whether social China, Czech dominance differences between Republic, Great Convenience Philips 2011 countries influence attitudes Britain, Iran, Ireland, Online survey QUANT and 3432 55 [51] towards the use of animals, by South Korea, questionnaire random surveying the student population Macedonia, Norway, in a range of Eurasian countries. Serbia, Spain, and Sweden To provide insights into the relationship between motives Online survey and the expression of questionnaire and Ploll 2019 [52] behavioural patterns of Austria QUANT Convenience 556 80 hard copy in vegetarians and vegans in person comparison to the average omnivore. To analyse consumer environmental consciousness, including problem awareness Pohjolainen and support to action Finland QUANT Questionnaire Random 1890 56 2016 [73] dimensions, the latter including perceived self-efficacy as well as solutions to problems. To examine differences between the attitudes and beliefs of four dietary groups (meat eaters, meat avoiders, vegetarians, and Povey 2001 vegans) and the extent to which United Kingdom QUANT Questionnaire Convenience 111 40 [53] attitudes influence intentions to follow each diet. Additionally, the role of ambivalence was examined. To examine whether reasons to Pribis 2010 adopt vegetarian lifestyle differ USA QUANT Questionnaire Convenience 609 65 [54] significantly among generations. To explore vegetarians concerns Ruby 2013 about the impact of their daily NR QUANT Questionnaire Convenience 272 65 (Study 1) [55] food choices on the environment and on animal suffering. To investigate whether the alleged link between meat consumption and particular framings of masculinity, which emphasise that ‘real men’ eat Questionnaire Quota Schösler 2015 meat, may stand in the way of Netherlands QUANT administered face and 1057 52 [56] achieving objectives. To analyse to face snowball whether meat-related gender differences vary across ethnic groups (Turkish, Chinese, and Native Dutch). Int. J. Environ. Res. Public Health 2023, 20, 286 11 of 25 Table 1. Cont. Type of Data Collection Included Gender (% Study Id * Primary Focus Country Sampling Study Methods Participants Female) To examine whether the perceptions of various Siegrist 2015 environment-related food Postal survey Switzerland QUANT Random 2781 54 [57] consumption patterns changed questionnaire between 2010 and 2014 and what factors influenced such changes. To examine how consumers evaluated the environmental impact of various foods, and to investigate whether the Siegrist 2019 Postal survey perceived environmental effect of Switzerland QUANT Random 5586 52 [78] questionnaire foods, health consciousness, and food disgust sensitivity is related to the consumption of meat substitutes and organic meat. To examine dietary and other personal health characteristics, as Spencer 2007 well as mentoring and clinical Paper-based USA QUANT Convenience 1849 NR [58] characteristics, for association questionnaire with US medical students’ vegetarianism. To examine consumers’ beliefs about ecological food Tobler 2011 Postal survey consumption and their Switzerland QUANT Random 6189 52 [75] questionnaire willingness to adopt such behaviours. To explore people’s perceptions Truelove 2012 and attitudes of behaviour that Online survey USA QUANT Convenience 112 61 [76] cause and mitigate global questionnaire warming. To explore consumer attitudes Vanhonacker Online survey towards a series of food choices Belgium QUANT Convenience 221 64 2013 [77] questionnaire with a lower ecological impact. To explore different types of sustainable food behaviours. A distinction between sustainable Verain 2015 product choices and curtailment Online survey Netherlands QUANT Quota 942 50 [59] behaviour is empirically questionnaire investigated and predictors of the two types of behaviours are identified. To investigate the eating patterns and vocabularies of motives for Semi-structured Boyle 2011 [79] US QUAL Snowball 45 100 newly practicing, or interviews developmental, vegetarians. To examine, by means of online ethnographic methods, vegetarians’ own perspectives on how health, ethical, and environmental beliefs motivate Fox 2008 [80] their food choices; to investigate US, UK, Canada QUAL Interviews Convenience 33 70 the interactions between beliefs on health, animal cruelty, and the environment, and how these may contribute to food choice trajectory. To contribute to a further understanding of the psychological factors that may hinder or promote a personal disposition to change food habits Graça 2014 Semi-structured to benefit each of these domains, Portugal QUAL Convenience 40 63 [81] focus groups and to explore people’s opinions about how different lifestyles and behaviours affect the environment, public health, and animals. Int. J. Environ. Res. Public Health 2023, 20, 286 12 of 25 Table 1. Cont. Type of Data Collection Included Gender (% Study Id * Primary Focus Country Sampling Study Methods Participants Female) To investigate interpersonal Guerin 2014 interactions and conflicts US QUAL Interviews Snowball 19 53 [82] between vegans and omnivores. To uncover the way in which attitudes and behavioural Happer 2019 commitments might be China, Brazil, UK, US QUAL Focus groups Quota 270 NR [83] negotiated in response to new information and through interaction with others. To investigate consumers’ perceptions, experiences, and Semi-structured, Hoek 2016 [84] attitudes toward health and Australia QUAL virtual, face-to-face Quota 29 56 environmental aspects in relation interviews to foods. To investigate consumers’ perceived barriers and benefits of Lea 2005 [85] plant food consumption and Australia QUAL Focus groups Convenience 50 72 views on the promotion of these foods. To explore in depth the public’s view and perception of the environmental impact of food and awareness of the link Macdiarmid between climate change and Scotland QUAL Focus groups Purposive 87 54 2016 [86] meat, and to gauge the public’s opinion about their willingness to eat less meat as part of a more sustainable diet. To investigate consumer value Quota residing in meat consumption, Semi-structured, Mceachern sampling with special emphasis on factors Scotland QUAL in-depth 30 100 2002 [87] and snow- relating to organic production interviews balling values. To understand how vegans and vegetarians conceptualise and In-depth, Purposive Myceck 2018 explain their food consumption US QUAL face-to-face and snow- 20 0 [88] identities in relation to their interviews balling broader identity practices. To understand how meat consumers enact ‘meat reduction’ Mylan 2018 in the context of their everyday Semi-structured UK QUAL Convenience 20 NR [89] lives, exploring the motivations, interviews strategies, and experiences of eating less meat. To gain an understanding of consumers’ arguments in making Spendrup 2017 a conscious consumer choice of Sweden QUAL Focus groups Purposive 21 NR [90] protein and the strategies used for reaching such a purchase decision. To investigate whether Norwegian consumers are ready Online Austgulen to make food choices based on Norway MM questionnaire and Quota 1532 50 2018 [91] what is environmentally focus groups sustainable. To investigate how people reason and explain their apparently unsustainable actions given their Face-to-face survey Scott 2019 [92] environmental beliefs and how Spain MM Convenience 42 43 questionnaire people that one would think were more prone to being vegetarian justify their choice to eat meat. Abbreviations: MM = mixed methods, NR = not reported, QUAL = qualitative, QUANT = quantitative, UK = United Kingdom, US = United States. * Studies are organised by type of study (quantitative, qualita- tive, and mixed methods) and are in alphabetical order. 4. Findings We identified four main themes: (1) reasons for eating meat (8 quantitative stud- ies (28,923 participants), 1 qualitative study (30 participants)); (2) reasons for avoiding meat (29 quantitative studies (64,651 participants), 7 qualitative studies (457 participants), Int. J. Environ. Res. Public Health 2023, 20, 286 13 of 25 and 1 mixed-methods study contributing quantitative evidence (1532)); (3) willingness to change meat consumption (27 quantitative studies (54,326 participants), 7 qualitative studies (527 participants), and 2 mixed-methods studies contributing qualitative evidence (66 participants)); and (4) willingness to pay more for environmentally friendly meat (2 quantitative studies (2702 participants)). Table S6–Table S9 present the integrated find- ings and the confidence in the evidence. 4.1. Reasons for Eating and/or Buying Meat 4.1.1. Quantitative Data Set Eight studies reported on reasons for eating and/or buying meat [25–32]. Among these studies, three (37%) provided participants with data on the environmental im- pact of meat [25,26,29] while five (63%) did not present participants with any informa- tion [27,28,30–32]. Informing about the Environmental Impact When provided with carbon footprint information on meat production, consumers chose products with a lower footprint [25,26,29]. One study found that information on the impact of the carbon footprint provided was meat-type-specific: when participants were given information on the carbon footprint impact of beef products, they were more likely to choose products with a lower footprint. However, in the case of pork meat, the impact was the opposite with participants choosing products with a higher footprint [29]. Moreover, when participants were asked what product features of minced meat had a significant impact on their diet choices, the method of production (conventional, health and safety-oriented, animal-welfare-oriented, and organic production) was important to the minority, while low fat content and price were the most important attributes [29]. In another study, although consumers opted for products with lower carbon footprint labels, other aspects were considered more important, such as the type of meat (e.g., beef vs. turkey) and fat content [25]. Authors also reported that women with a higher income were more concerned with their meat choices based on both their health and environmental impact [25]. Not Informing about the Environmental Impact When participants were asked to report which meat attribute was important when buy- ing/consuming meat, the environment (for example, carbon footprint information on the la- bel) was not considered the most important characteristic [27,28,30–32], while other aspects such as: nutritional values [28,32], freshness of the meat [27], food safety [27,28,30,31], eat- ing enjoyment/taste [27,30,31], and animal welfare [28,31] were considered more important. 4.1.2. Qualitative Data Set One study reported on reasons for eating and/or buying meat and did not provide any information about the environmental impact of meat to participants [87]. People bought meat products based on tangible aspects such as colour and appearance rather than more intangible characteristics including environmental aspects of produc- tion [87]. Only some participants bought environmentally friendly meat products; the main barriers mentioned were the higher price of these products and their general unwillingness to change their diet [87]. 4.1.3. Integrated Evidence and Related Confidence Findings from the quantitative and qualitative data sets were deemed complementary and the overall confidence in the evidence was rated as low because of moderate concerns of methodological limitations/risk of bias and serious concerns of relevance. The integrated evidence and related confidence are presented in Table S9. Int. J. Environ. Res. Public Health 2023, 20, 286 14 of 25 4.2. Reasons for Avoiding Meat 4.2.1. Quantitative Data Set Thirty studies reported on reasons for avoiding meat [32–59,91]. None of the studies provided participants with data on the environmental impact of meat. Eleven studies reported that environmental concerns were among the most important reasons for avoiding meat consumption among vegetarians and low-meat consumers/meat reducers [35,43,44,46,48,49,52,54,55]. One study found that environmental concerns were among the most important reasons for being vegetarian together with health [54]. One study reported environmental concerns together with animal welfare as the main reasons to avoid or limit meat intake [44], and similarly, two studies reported that vegetarians agreed more on the benefits for the environment and animal welfare, or meat reduction, compared with the potential benefits of preventing diseases (e.g., heart disease and cancer) [35,46,49]. On the other hand, 12 studies reported that environmental concerns were not among the main reasons for avoiding meat [35,37,39–42,45,47,53,56,58,91]. Health benefits and the high costs of meat [47], animal welfare together with health [37,39,45,53,58], taste/dislike of meat [35,56] together with animal welfare [35] or health reasons [56], and animal welfare alone [40,41] were the more prominent reasons for avoiding meat in these studies. One study reported that health, the environment, and animal rights were all considered to be generally compelling reasons to adopt a plant-based diet but with health motives being the most common reason [42]. Another study reported that although participants believed that a reduction in meat intake had benefits to the environment, most of the participants who reported having reduced their intake in the past did not do it for environmental reasons [91]. Four studies reported that, overall, women, compared with men, were more likely to avoid meat or eat smaller portions of meat for environmental reasons [33,39,49,59]. On the other hand, in one study men were more likely to report environmental concerns as a reason for avoiding meat compared with women who reported health as the main reason for avoiding meat intake, particularly red meat—beef, lamb and to some extent pork [51]. Two studies reported that younger populations were more likely to agree that there are environmental benefits associated with the consumption of a vegetarian diet [45,54], while those middle-aged appeared to be motivated by health reasons [54]. In one study, individuals with higher education and living alone were more likely to report a dilemma between buying meat for health reasons and not buying it for environmental reasons [32]. In addition, people with higher levels of awareness of the potential environmental impact of meat consumption were more likely to eat less meat and eat more meat substitutes [57]. Finally, three studies reported that people’s motivations for avoiding meat intake were influenced by their dietary behaviour; the stricter the diet in terms of avoiding meat consumption and animal products people followed, the more important environmental concerns were as reasons to avoid meat [34,38,47]. 4.2.2. Qualitative Data Set Seven studies reported on reasons for avoiding meat consumption [79,80,82,83,85,88,89]. One study (14%) provided participants with information on the environmental impact of meat production [83], and six studies (86%) did not [79,80,82,85,88,89]. Five studies reported that environmental concerns were not among the main rea- sons for having reduced meat intake [79,80,83,88,89]; other reasons such as animal wel- fare [80,89]; health concerns [80,89]; self-fulfilment; and taste or aesthetics (such as colour and appearance) [79] were considered among the main reasons for avoiding meat. How- ever, for some participants, the environmental impact of meat production was mentioned as one important reason for avoiding meat intake [79]. Similarly, another study reported that environmental benefits were considered important reasons for following a more plant- based diet along with the perceived health benefits of plant foods and their taste, variety, and versatility [85]. Environmental concerns tended to be a contributory factor rather than the primary driver for avoiding meat [83]; people might have started avoiding meat for a Int. J. Environ. Res. Public Health 2023, 20, 286 15 of 25 specific reason such as the decision to protect animals, but later other reasons such as health concerns or environmental protection reinforced and supported the choice of avoiding meat [82]. Environmental concerns about meat consumption were considered important de- pending on participants’ dietary behaviour; one study reported that all vegans found the environment an important issue for meat consumption, while only a minority of omnivores mentioned it [82]. 4.2.3. Integrated Evidence and Related Confidence Findings from quantitative and qualitative data sets were deemed complementary and the overall confidence in the evidence was rated as low because of minor concerns of methodological limitations/risk of bias, minor concerns of coherence, and serious concerns of relevance. The integrated evidence and related confidence are presented in Table S10. 4.3. Willingness to Change Meat Consumption 4.3.1. Quantitative Data Set Twenty-seven studies evaluated people’s willingness to change meat consumption [31, 33,45,47,50,56,57,59–73,75,77,78]. Three studies (12%) provided participants with data on the environmental impact of meat consumption [33,66,68], whereas twenty-four studies (88%) did not present participants with any information [31,45,47,50,56,57,59–65,67,69– 73,75,77,78]. Informing about the Environmental Impact When informed about the environmental impact of meat, most participants reported low willingness to reduce their meat intake [33,66,68], partially because they mistrusted the information provided [33] and because other strategies such as replacing beef, for example, with chicken every other meal [68] or reporting the ecological impact on the food’s labels [66] were believed to be more favourable for the environment. Moreover, they believed that by stopping meat consumption completely, their actions would have no effect on mitigating climate change. One study provided participants with a fictional newspaper article describing the potential environmental damage of meat production (e.g., greenhouse gas emissions) [33]; in a second study participants were given a fact sheet on the impact of meat on the climate and presented with information indicating that a reduction in meat intake would reduce greenhouses gas emissions and that beef and mutton have significantly higher emission costs than other meats [66]. A third study presented participants with a one-page cover story reporting the causes and consequences of and mitigating actions for climate change in relation to meat consumption [68]. Not Informing about the Environmental Impact When people were asked if they would be willing to reduce their meat intake in the future, most of them reported that they would not reduce their consumption [56,60,63,64, 69,70,73,75–78]. Several reasons and/or barriers were reported for not wanting to reduce meat intake [45,48,50,61,71,92]. See Figure 2. Two studies found that the perception of barriers was gender-specific: women consid- ered high prices and poor supply to be more important barriers for reducing meat, whereas men considered disbelief, strangeness, eating habits [71], and the enjoyment of eating meat more important [31]. In addition, seven studies identified the behaviours participants believed to favour the environment [47,60,64,70,78,80]. Buying local and seasonal food [47,61,65,67,68,72,77], (Study 1 in [67]), decreased use of packaging [47,60,70,75], reducing food waste [61,79], driving less [68,82], and using less energy at home [67,77] (Study 1 in [67]) were behaviours believed to be more efficient in mitigating climate change. Barriers for meat reduction High price of non-meat products [45,48,49,62,73,94] Int. J. Environ. Int. J. Environ. Res. Res. Public Public Health Health 2022, 20, x286 2023, 19, 16of 16 of 25 5% Taste and enjoyment [45,48,49,62] 10% 32% Unwillingness to alter eating habits Barriers for meat reduction [45,62,73] 16% High of Lack price ofinnon-meat time products making enviromentally [45,48,49,62,73,94] friendly choices [48,49,73] 5% Taste andthat Disbelief enjoyment people's[45,48,49,62] food behaviour 10% could impact climate change [73,94] 16% 32% 21% Unwillingness Meat to alter is necessary for aeating habits healthy diet [51] [45,62,73] 16% Lack of time in making enviromentally friendly choices [48,49,73] Figure 2. Barriers for meat reduction—quantitative data set. Disbelief that people's food behaviour could impact climate change [73,94] Two studies found that the perception of barriers was gender-specific: women con- 16% sidered high prices21% and poor supply to be more important barriers for reducing meat, Meat is necessary for a healthy diet [51] whereas men considered disbelief, strangeness, eating habits [73], and the enjoyment of eating meat more important [31]. In addition, seven studies identified the behaviours participants believed to favour the environment [47,61,65,68,72,80,82]. Buying local and seasonal food [47,61,65,68,72,77], Figure 2. Figure 2. Barriers decreased use offor Barriers for meat reduction—quantitative packaging meat reduction—quantitative data food [47,61,72,77], reducing data set. * Study set. waste1[61,79], driving and Study 2. less [68,82], and using less energy at home [68,79] were behaviours believed to be more efficient in Two studies Similarly, most found that thereported omnivores perception of willing to be barriersto was gender-specific: adopt women or accept other con- strategies mitigating climate change. sidered to reduce high prices the climate and poor supply impact rather to be more than reducing important barriers meatto[67,73,76,78] for (Studyreducing meat, 2 in strategies [67]). See Similarly, most omnivores reported to be willing adopt or accept other whereas Figure 3. men considered disbelief, strangeness, eating habits [73], and the enjoyment of to reduce the climate impact rather than reducing meat [58,67,69,75,78,80]. See Figure 3. eating meat more important [31]. In addition, seven studies identified the behaviours participants believed to favour Behaviours participants the environment would beBuying [47,61,65,68,72,80,82]. willing localtoand adopt seasonalorfood [47,61,65,68,72,77], decreased use of packaging [47,61,72,77], reducing food waste [61,79], driving less [68,82], accept and usingin less theenergy future to favour at home the behaviours [68,79] were enviroment believed to be more efficient in mitigating climate change. Eating more organic food [69,80,75] Similarly, most omnivores reported to be willing to adopt or accept other strategies to reduce the climate impact rather than reducing meat [58,67,69,75,78,80]. See Figure 3. 13% Eating local foods [80,75] Behaviours 13% participants 37% would be willing to adopt or accept in the future to favour the Driving lessenviroment [78] Eating more organic food [69,80,75] 12% Using alternate transportation, recycling and 13% using eco-friendly products [78] Eating local foods [80,75] 25% Reporting the ecological impact on the food’s 13% 37% labels [67] Driving less [78] Figure 3. Behaviours participants would be willing to adopt or accept in the future to favour the 12% environment. * Study 2. Using alternate transportation, recycling and using eco-friendly products [78] Nevertheless, three studies reported that most of the participants, when presented 25%sustainable food behaviours with different they Reporting thecould choose ecological from, impact were on the willing to reduce food’s their meat intake [59,65,80]. One study labelsreported [67] that participants were more willing to reduce the meat quantity in their traditional meal rather than eating plant-based meat substitutes and proteins from insects [80]. In another study, most participants were willing Int. J. Environ. Res. Public Health 2023, 20, 286 17 of 25 to eat less meat but of better quality (certified origin) instead of replacing most of the meat with vegetables [65], and in a third study, participants were more willing to reduce meat intake (eat smaller portions, take a meat-free day per week) than buy organic meat, buy free range meat, or eat less dairy [59]. Thirteen studies reported that, overall, women perceived higher environmental bene- fits of eating less meat than men and were more willing to reduce meat intake [31,56,59,61– 65,69,70,75,76,78], and women were more likely to have already reduced their meat con- sumption in the past [75]. Similarly, two studies reported that women had more positive views of vegetarianism and veganism compared with men [61,71]. Generally, male respon- dents and with higher incomes [71] were less willing to reduce their meat intake. Moreover, participants with higher education and socio-economic status were more willing to reduce their overall meat intake in the future [56,57,59,69]. In addition, smaller household sizes and higher age levels appear related to a higher level of meat curtailment [59]. Finally, participants who consumed meat in larger quantities and more frequently were less positive towards a reduction in meat intake [63–65,67,72,75], whereas those with higher concerns for environmental problems were much more likely to intend to stop eating meat [63,67,75,76]; also, an increased scepticism toward climate change was associated with a decrease in people’s willingness to change their meat consumption [63]. Contrary to the above, one study found that gender, as well as age, meat consumption behaviour (high vs. low intake), and socio-economic status differences, had no impact on people’s belief that eating less meat would help reduce climate change [62]. 4.3.2. Qualitative Data Set Eight studies evaluated people’s willingness to change meat consumption when faced with environmental concerns of meat consumption [81,83–87,90,91]. One study (12%) provided participants with data on the environmental impact of meat [83], and seven studies (88%) did not provide any information [81,84–87,90,91]. Informing about the Environmental Impact When provided with an information sheet about the impact of food production on climate change, most of the participants showed a low level of awareness of the associ- ation between climate change and meat consumption, and some participants reported considering reducing their meat consumption or had already reduced their intake in the past. However, environmental concerns tended to be a contributory factor rather than the primary driver; other aspects were reported to be more important for the environment and were country/culturally specific; for example, deforestation in Brazil was considered more important and harmful for the environment compared with meat consumption. Moreover, participants were sceptical of the credibility of sources and arguments reported by the media about the impact of meat consumption [83]. Not Informing about the Environmental Impact Most of the participants were reluctant to reduce their meat intake for a more environ- mentally friendly diet [81,84,86,91], and overall, there was a lack of awareness of the climate impact of meat production [84,86,87,91]. On the other hand, although some participants recognised the importance of reducing meat consumption, they expressed difficulties in being a sustainable consumer daily [90]. Several reasons and/or barriers were reported for not wanting to reduce meat intake. Figure 4 shows people’s barriers to reducing meat consumption [81,84–86,90,92]. In relation to people’s scepticism about the serious impact that meat consumption has on the environment [91] and the disbelief that consumers could solve such a major issue [81,86,91,92], among the minority who said that they would consider eating less meat were those more inclined to do this for health benefits rather than environmental gains or only willing if there was evidence to support that it was indeed beneficial [86]. Int. J. Environ. Res. Public Health 2022, 19, x 18 of 25 participants recognised the importance of reducing meat consumption, they expressed difficulties in being a sustainable consumer daily [92]. Several reasons and/or barriers Int. J. Environ. Res. Public Health 2023, 20, 286 18 of 25 were reported for not wanting to reduce meat intake. Figure 4 shows people’s barriers to reducing meat consumption [83,86–88,92]. Barriers for meat reduction Tradition and family preferences[87,88,92,94] Disbelief that people's meat behaviour 7% could impact climate change [83,88,93,94] 7% 27% Lack of knowledge and time for preparing 6% plant-based meals [87,92] Lack of alternatives to meat [83,87] 13% Taste and enjoyment [88] 13% 27% Meat is an important part of a healthy diet [86] High price of non-meat products [94] Figure 4. Figure 4. Barriers Barriers to to meat reduction—qualitative data meat reduction—qualitative data set. set. In relation Others to people’s believed scepticism that compared withabout otherthe serious impact behaviours that meat consumption meat consumption was trivial has on the environment [93] and the disbelief that consumers and other behaviours would be more favourable for the environment than could solvereducing such a major meat issue [83,88,93,94], consumption, food among packaging the minority who said (e.g., plastics, that they recycling), foodwould wasteconsider eating (e.g., sell-by less dates, meat were those promotions, more inclined household waste), theto transportation do this for health benefits of food (e.g.,rather than environmental food miles, imported food, gainsfood, local or only willing if there seasonality), wasproduction and the evidence toand support that itof processing was indeed food (e.g., beneficial agricultural[88]. and retailOthers believed practices, factorythat compared pollution) with other behaviours meat consumption was trivial [86]. and other Youngbehaviours women were would most beinclined more favourable to changefor themeat their environment consumption thancompared reducing meat with consumption, men [91]. food packaging (e.g., plastics, recycling), food waste (e.g., sell-by dates, pro- motions, household waste), the transportation of food (e.g., food miles, imported food, 4.3.3. Integrated local food, Evidence seasonality), andand theRelated Confidence production and processing of food (e.g., agricultural and retailFindings from practices, quantitative factory pollution)and qualitative data sets were deemed complementary and [88]. the overall Youngconfidence women were in the mostevidence inclinedwas rated as to change lowmeat their because of moderate consumption concerns compared of with methodological men [93]. limitations/risk of bias and serious concerns of relevance. The integrated evidence and related confidence are presented in Table S11. 4.3.3. Integrated evidence and related confidence 4.4. Willingness to Pay More for Environmentally Friendly Meat Findings from quantitative and qualitative data sets were deemed complementary Quantitative Data Set and the overall confidence in the evidence was rated as low because of moderate concerns Two studies evaluated of methodological people’sof limitations/risk willingness to pay more bias and serious for environmentally concerns of relevance. The friendly inte- meat and meat products [26,74]. None of the studies grated evidence and related confidence are presented in Table S11.provided participants with data on the environmental impact of meat consumption. Both studies 4.4. Willingness reported to pay that more for consumers were environmentally willing friendly meatto pay more for meat produced with a significantly lower environmental impact [26,74]. Labels indicating that the beef 4.4.1. Quantitative data set mince had a low or moderate fat content [74], was organic meat produced locally, and met animal welfare standards were also significant for consumers [26]. Women and older people showed higher willingness to pay more for meat with minimal environmental impact [26,74]. Findings were only reported from quantitative data sets and the overall confidence in the evidence was rated as moderate because of no or minor concerns of methodological limitations (serious risk of bias), serious concerns of relevance, and minor concerns of adequacy. The evidence and related confidence are presented in Table S12. Int. J. Environ. Res. Public Health 2023, 20, 286 19 of 25 5. Discussion 5.1. Main Findings Our findings show that overall people are highly attached to meat. People are divided between those who believe that meat consumption has a harmful impact on the environ- ment and those who believe that other factors, for example, food waste and food packaging, are more harmful to the environment compared with meat. Regardless of people’s general beliefs about meat and its impact on the environment, most people in our included studies were unwilling to change their meat consumption, and, among those who did already reduce their meat intake in the past, environmental concerns were not always the main reasons but often a contributory factor among others. People reported several barriers to reducing their meat intake: the high price of non- meat products, its taste, unwillingness to alter their eating habits, the lack of time to make climate-friendly choices, and disbelief that meat has an impact on climate change. Even in the few studies in which participants were presented with scientific evidence linking meat consumption and climate change, consumers did not consider the environment an important aspect when buying/eating meat, nor were they willing to reduce their meat intake. Our findings are consistent across quantitative and qualitative evidence and across countries and publication years; the overall confidence was low for the themes reasons for eating and/or buying meat, reasons for avoiding meat, and willingness to change meat consumption, and moderate for the willingness to pay more for environmentally friendly meat theme. 5.2. Strengths and Limitations Our study has several strengths. We performed a mixed-methods systematic review, including both quantitative and qualitative evidence, allowing us to have greater confidence in the interpretation of our findings. We explicitly reported inclusion and exclusion criteria, conducted an extensive search, and performed a duplicate assessment of eligibility and RoB or ML based on a publicly available protocol [13]. We applied the GRADE-CERQual approach to assess the overall certainty of our findings in consultation with GRADE and mixed-methods research experts. Our study also has some limitations. First, we only included studies conducted in Europe, Australia, Canada, the United States, and New Zealand, and therefore our results reflect those of populations living in high-income countries. While limited data were available, we did not explore whether values and preferences differed in lower versus higher income participants in our eligible studies. Second, most of the included studies did not inform participants about the environmental impact of meat, and therefore their values and preferences were based solely on their personal knowledge or belief. Third, given that some of the authors have recently published a weak dietary recommendation that people continue their meat consumption [9], it is possible that our interpretation of results is biased. To help mitigate this possibility, in addition to duplicate independent data screening and abstraction and a risk-of-bias assessment, we included data abstractors and assessors who were not part of our recommendations. Finally, among the eight studies that did present participants with information on the environmental impact, we did not assess the credibility of this information, nor did we assess if participants were presented with the relative impacts of various behavioural changes that can impact global warming. Moreover, we were not able to investigate in depth if the results were dependent on the age of participants because the age of participants was not consistently reported across studies. 5.3. Our Results in the Context of Previous Research Our findings are aligned with results from a previous synthesis [93,94]. One systematic review including only quantitative studies reported that only a small minority of included participants were willing to reduce their meat consumption for environmental reasons [93]. The same authors conducted a qualitative synthesis, reporting that the main barriers to meat reduction were the taste of meat, the belief that meat is healthy, and that it is a part Int. J. Environ. Res. Public Health 2023, 20, 286 20 of 25 of a nutritious diet [94]. In addition, people who had already reduced or eliminated meat from their diet (vegetarians and vegans) did not do so solely for environmental reasons. 5.4. Implications for Research and Practice Our results have direct implications for several stakeholders such as guideline devel- opers, researchers, and policymakers. Our findings suggest that people are unwilling to change their eating habits and prefer to continue doing what they know and are familiar with, regardless of the alleged impact their behaviour might have on the environment. Based on our findings, it is likely that people will be reluctant to follow plant-based food recommendations contrary to their individual values and preferences. However, people in most of the included studies were not properly informed about the evidence, partic- ularly the best available evidence or the relative impact of changing meat consumption versus various other behavioural changes on the environment. Future research should address these limitations and assess whether people are willing to make a change when properly informed. Regarding our methods, this systematic review follows and reports step by step an innovative methodological approach to synthesise and assess the confidence of mixed- methods evidence by following solely the GRADE-CERQual approach. This approach could be adopted for future mixed-methods systematic review syntheses for different research areas. 6. Conclusions Regardless of people’s general beliefs about meat and its impact on the environment, most people may be unwilling to change their meat consumption; however, they have reported to be willing to adopt other, non-food-related strategies (for example, driving less) to mitigate climate change. Most of the participants were not informed about the conse- quences and impact on climate change, and therefore we cannot confidently conclude that people when properly informed would still be reluctant to change. Future research should address the current limitations of the research evidence (e.g., rather than perceived impact; robust, systematic evidence of the relative environmental impact of locally sourced vs fac- tory farmed meats) to assess whether people are willing to change their meat consumption when properly informed. Supplementary Materials: The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/ijerph20010286/s1, Figure S1: Search Strategies; Table S2: Quan- titative Data Extraction Form; Table S3: Qualitative Data Extraction Form; Table S4: Critical Meta- narrative Synthesis: From Quantitative Data to Narratives; Table S5: Excluded Studies and Reasons for Exclusion (N = 357); Table S6: Risk-of-Bias Assessments for Quantitative Studies; Table S7: Methodological Limitations Assessments for Qualitative Studies; Table S8: Critical appraisal of Mixed-Methods studies; Table S9: Evidence Profile for “Reasons for eating and/or buying meat”; Table S10: Evidence Profile for “Reasons for avoiding meat”; Table S11: Evidence Profile for “Willing- ness to Change Meat Consumption”; Table S12: Evidence Profile for “Willingness to pay more for environmentally friendly meat”. Author Contributions: C.V., A.P.-D., M.R., I.S., J.Z., B.C.J., G.H.G., M.M.B. and P.A.-C. conceived the idea and were involved in the development of the study protocol. C.V. and I.S. designed the search strategy. C.V., M.M., A.P.-D., C.K., C.S. and J.Z. were involved in screening of the references and in the data extraction. C.V., M.M., A.P.-D. and C.K. performed the analysis. All authors reviewed the data extraction output. C.V. drafted the manuscript under the supervision of M.R. and P.A.-C. All authors have read and agreed to the published version of the manuscript. Funding: This research received no external funding. Institutional Review Board Statement: Not applicable. Informed Consent Statement: Not applicable. Int. J. Environ. Res. Public Health 2023, 20, 286 21 of 25 Data Availability Statement: All data generated or analysed during this study are included in this published article and its Supplementary Information Files. Acknowledgments: Claudia Valli is a doctoral candidate for the PhD in Methodology of Biomedical Research and Public Health (Department of Paediatrics, Obstetrics, Gynaecology and Preventive Medicine), Universidad Autònoma de Barcelona, Barcelona, Spain. The authors would like to thank Claire Glenton from the GRADE-Cerqual working group and Katy Sutclif, an expert in mixed- methods research from UCL IRIS—Institutional Research Information Service, for their valuable input to our methodological approach. Conflicts of Interest: BCJ received a 2019 start-up grant from Texas A&M AgriLife Research to fund investigator-initiated research related to saturated and polyunsaturated fats. The grant was from Texas A&M AgriLife institutional funds from interest and investment earnings, not a sponsoring organisation, industry, or company. The rest of the authors conducted this study independently without involvement of a funder. No further competing interests are disclosed. The authors declare that no funding grants were involved in supporting this work. The authors are all part of the NutriRECS working group and have previously published a series of systematic reviews, along with guidelines on red and processed meat consumption. Abbreviations AGRIS International System for Agricultural Science and Technology CAB abstracts Centre for Agriculture and Bioscience CERQual Confidence in the Evidence from Reviews of Qualitative Research CASP Critical Appraisal Skills Programme CMNS critical meta-narrative synthesis FSTA Food Science and Technology Abstracts ML methodological limitations NutriRECS Nutritional Recommendations and accessible Evidence summaries Composed of Systematic reviews PROSPERO International Prospective Register of Systematic Reviews RoB risk of bias References 1. Caso, G.; Vecchio, R. Factors influencing independent older adults (un)healthy food choices: A systematic review and research agenda. Food Res. Int. 2022, 158, 111476. [CrossRef] 2. Hardcastle, S.J.; Thøgersen-Ntoumani, C.; Chatzisarantis, N.L.D. Food Choice and Nutrition: A Social Psychological Perspective. Nutrients 2015, 7, 8712–8715. [CrossRef] [PubMed] 3. Valli, C.; Rabassa, M.; Johnston, B.C.; Kuijpers, R.; Prokop-Dorner, A.; Zajac, J.; Storman, D.; Storman, M.; Bala, M.M.; Solà, I.; et al. Health-Related Values and Preferences Regarding Meat Consumption: A Mixed-Methods Systematic Review. Ann. Intern. Med. 2019, 171, 742–755. [CrossRef] [PubMed] 4. de Boer, J.; Aiking, H. Considering how farm animal welfare concerns may contribute to more sustainable diets. Appetite 2022, 168, 105786. [CrossRef] [PubMed] 5. Garza, C.; Stover, P.J.; Ohlhorst, S.D.; Field, M.S.; Steinbrook, R.; Rowe, S.; Woteki, C.; Campbell, E. Best practices in nutrition science to earn and keep the public’s trust. Am. J. Clin. Nutr. 2019, 109, 225–243. [CrossRef] 6. Dedios, M.C.; Esperato, A.; De-Regil, L.M.; Peña-Rosas, J.P.; Norris, S.L. Improving the adaptability of WHO evidence-informed guidelines for nutrition actions: Results of a mixed methods evaluation. Implement. Sci. 2017, 12, 39. [CrossRef] 7. Rabassa, M.; Ruiz, S.G.-R.; Solà, I.; Pardo-Hernandez, H.; Alonso-Coello, P.; García, L.M. Nutrition guidelines vary widely in methodological quality: An overview of reviews. J. Clin. Epidemiol. 2018, 104, 62–72. [CrossRef] 8. Rabassa, M.; Ponce, Y.H.; Garcia-Ribera, S.; Johnston, B.C.; Castell, G.S.; Manera, M.; Rodrigo, C.P.; Aranceta-Bartrina, J.; Martínez-González, M.; Alonso-Coello, P. Food-based dietary guidelines in Spain: An assessment of their methodological quality. Eur. J. Clin. Nutr. 2022, 76, 350–359. [CrossRef] 9. Johnston, B.C.; Zeraatkar, D.; Han, M.A.; Vernooij, R.W.M.; Valli, C.; El Dib, R.; Marshall, C.; Stover, P.J.; Fairweather-Taitt, S.; Wójcik, G.; et al. Unprocessed Red Meat and Processed Meat Consumption: Dietary Guideline Recommendations From the Nutritional Recommendations (NutriRECS) Consortium. Ann. Intern. Med. 2019, 171, 756–764. [CrossRef] 10. Steinfeld, H.; Gerber, P.; Wassenaar, T.D.; Castel, V.; Rosales, M.; de Haan, C. Livestock’s Long Shadow: Environmental Issues and Options; Food and Agriculture Organization of the United Nations (FAO): Rome, Italy, 2006; Available online: https: //www.fao.org/3/a0701e/a0701e.pdf (accessed on 17 March 2020). Int. J. Environ. Res. Public Health 2023, 20, 286 22 of 25 11. Bouwman, L.; Goldewijk, K.K.; Van Der Hoek, K.W.; Beusen, A.H.W.; van Vuuren, D.P.; Willems, J.; Rufino, M.C.; Stehfest, E. Exploring global changes in nitrogen and phosphorus cycles in agriculture induced by livestock production over the 1900–2050 period. Proc. Natl. Acad. Sci. USA 2013, 110, 20882–20887. [CrossRef] 12. Dauvergne, P. The Shadows of Consumption: Consequences for the Global Environment; MIT Press: Cambridge, MA, USA, 2010; ISBN 0-262-26057-3. Available online: http://mitp-content-server.mit.edu:18180/books/content/sectbyfn?collid=books_pres_0id= 7706fn=9780262514927_sch_0001.pdf (accessed on 17 March 2020). 13. Valli, C.; Rabassa, M.; Zera, D.; Prokop-Dorner, A.; Zajac, J.; Swierz, M.; Storman, D.; Storman, M.; Król, A.; Jasińska, A.; et al. Adults’ Beliefs, Preferences and Attitudes about Meat Consumption: A Systematic Review Protocol. PROSPERO 2018 CRD42018088854. 2018. Available online: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42018088854 (accessed on 17 March 2020). 14. Page, M.J.; McKenzie, J.E.; Bossuyt, P.M.; Boutron, I.; Hoffmann, T.C.; Mulrow, C.D.; Shamseer, L.; Tetzlaff, J.M.; Akl, E.A.; Brennan, S.E.; et al. The PRISMA 2020 statement: An updated guideline for reporting systematic reviews. BMJ 2021, 372, 71. [CrossRef] [PubMed] 15. Zhang, Y.; Alonso Coello, P.; Guyatt, G.H.; Yepes-Nuñez, J.J.; Akl, E.A.; Hazlewood, G.; Pardo-Hernandez, H.; Etxeandia- Ikobaltzeta, I.; Qaseem, A.; Williams Jr, J.W.; et al. GRADE guidelines: 19. Assessing the certainty of evidence in the importance of outcomes or values and preferences—Risk of bias and indirectness. J. Clin. Epidemiol. 2019, 111, 94–104. [CrossRef] [PubMed] 16. Critical Appraisal Skills Programme. CASP (Qualitative) Checklist. Available online: https://casp-uk.net/casp-tools-checklists/ (accessed on 19 March 2022). 17. Hong, Q.N.; Pluye, P.; Fàbregues, S.; Bartlett, G.; Boardman, F.; Cargo, M.; Dagenais, P.; Gagnon, M.P.; Griffiths, F.; Nicolau, B.; et al. Mixed Methods Appraisal Tool (MMAT), version 2018. Registration of Copyright (#1148552), Canadian Intellectual Property Office, Industry Canada. 2018. Available online: http://mixedmethodsappraisaltoolpublic.pbworks.com/w/file/fetch/ 127916259/MMAT_2018_criteria-manual_2018-08-01_ENG.pdf (accessed on 17 March 2020). 18. Karimi, M.; Clark, A.M. How do patients’ values influence heart failure self-care decision-making?: A mixed-methods systematic review. Int. J. Nurs. Stud. 2016, 59, 89–104. [CrossRef] 19. Sandelowski, M.; Voils, C.I.; Barroso, J. Defining and Designing Mixed Research Synthesis Studies. Res. Sch. 2006, 13, 29–44. [PubMed] 20. Hong, Q.N.; Pluye, P.; Bujold, M.; Wassef, M. Convergent and sequential synthesis designs: Implications for conducting and reporting systematic reviews of qualitative and quantitative evidence. Syst. Rev. 2017, 6, 61. [CrossRef] [PubMed] 21. Fetters, M.D.; Curry, L.A.; Creswell, J.W. Achieving Integration in Mixed Methods Designs-Principles and Practices. Health Serv. Res. 2013, 48, 2134–2156. [CrossRef] 22. Guetterman, T.C.; Fetters, M.D.; Creswell, J.W. Integrating Quantitative and Qualitative Results in Health Science Mixed Methods Research Through Joint Displays. Ann. Fam. Med. 2015, 13, 554–561. [CrossRef] 23. Younas, A.; Pedersen, M.; Durante, A. Characteristics of joint displays illustrating data integration in mixed-methods nursing studies. J. Adv. Nurs. 2019, 76, 676–686. [CrossRef] 24. Lewin, S.; Bohren, M.; Rashidian, A.; Munthe-Kaas, H.; Glenton, C.; Colvin, C.J.; Garside, R.; Noyes, J.; Booth, A.; Tunçalp, Ö.; et al. Applying GRADE-CERQual to qualitative evidence synthesis findings—Paper 2: How to make an overall CERQual assessment of confidence and create a Summary of Qualitative Findings table. Implement. Sci. 2018, 13, 11–23. [CrossRef] 25. Apostolidis, C.; Mcleay, F. To meat or not to meat? Comparing empowered meat consumers’ and anti-consumers’ preferences for sustainability labels. Food Qual. Prefer. 2019, 77, 109–122. [CrossRef] 26. Eldesouky, A.; Mesias, F.J.; Escribano, M. Consumer Assessment of Sustainability Traits in Meat Production. A Choice Experiment Study in Spain. Sustainability 2020, 12, 4093. [CrossRef] 27. Frewer, L.J.; Kole, A.; Van de Kroon, S.M.A.; de Lauwere, C. Consumer Attitudes Towards the Development of Animal-Friendly Husbandry Systems. J. Agric. Environ. Ethic 2005, 18, 345–367. [CrossRef] 28. Grunert, K.; Sonntag, W.; Glanz-Chanos, V.; Forum, S. Consumer interest in environmental impact, safety, health and animal welfare aspects of modern pig production: Results of a cross-national choice experiment. Meat Sci. 2018, 137, 123–129. [CrossRef] [PubMed] 29. Koistinen, L.; Pouta, E.; Heikkilä, J.; Forsman-Hugg, S.; Kotro, J.; Mäkelä, J.; Niva, M. The impact of fat content, production methods and carbon footprint information on consumer preferences for minced meat. Food Qual. Prefer. 2013, 29, 126–136. [CrossRef] 30. McCarthy, M.; de Boer, M.; O’Reilly, S.; Cotter, L. Factors influencing intention to purchase beef in the Irish market. Meat Sci. 2003, 65, 1071–1083. [CrossRef] 31. McCarthy, M.; O’Reilly, S.; Cotter, L.; de Boer, M. Factors influencing consumption of pork and poultry in the Irish market. Appetite 2004, 43, 19–28. [CrossRef] 32. Péneau, S.; Fassier, P.; Allès, B.; Kesse-Guyot, E.; Hercberg, S.; Méjean, C. Dilemma between health and environmental motives when purchasing animal food products: Sociodemographic and nutritional characteristics of consumers. BMC Public Health 2017, 17, 876. [CrossRef] 33. Cordts, A.; Nitzko, S.; Spiller, A. Consumer Response to Negative Information on Meat Consumption in Germany. Int. Food Agribus. Manag. Rev. 2014, 17, 83–106. Int. J. Environ. Res. Public Health 2023, 20, 286 23 of 25 34. Crnic, A. Studying social aspects of vegetarianism: A research proposal on the basis of a survey among adult population of two Slovenian biggest cities. Coll. Antropol. 2013, 37, 1111–1120. 35. De Backer, C.J.; Hudders, L. From Meatless Mondays to Meatless Sundays: Motivations for Meat Reduction among Vegetarians and Semi-vegetarians Who Mildly or Significantly Reduce Their Meat Intake. Ecol. Food Nutr. 2014, 53, 639–657. [CrossRef] 36. de Gavelle, E.; Davidenko, O.; Fouillet, H.; Delarue, J.; Darcel, N.; Huneau, J.F.; Mariotti, F. Self-declared attitudes and beliefs regarding protein sources are a good prediction of the degree of transition to a low-meat diet in France. Appetite 2019, 142, 104345. [CrossRef] [PubMed] 37. Dyett, P.A.; Sabaté, J.; Haddad, E.; Rajaram, S.; Shavlik, D. Vegan lifestyle behaviors. An exploration of congruence with health-related beliefs and assessed health indices. Appetite 2013, 67, 119–124. [CrossRef] [PubMed] 38. Hagmann, D.; Siegrist, M.; Hartmann, C. Meat avoidance: Motives, alternative proteins and diet quality in a sample of Swiss consumers. Public Health Nutr. 2019, 22, 2448–2459. [CrossRef] [PubMed] 39. Haverstock, K.; Forgays, D.K. To eat or not to eat. A comparison of current and former animal product limiters. Appetite 2012, 58, 1030–1036. [CrossRef] 40. Herzog, H.A.; Golden, L.L. Moral Emotions and Social Activism: The Case of Animal Rights. J. Soc. Issues 2009, 65, 485–498. [CrossRef] 41. Hoffman, S.R.; Stallings, S.F.; Bessinger, R.C.; Brooks, G. Differences between health and ethical vegetarians. Strength of conviction, nutrition knowledge, dietary restriction, and duration of adherence. Appetite 2013, 65, 139–144. [CrossRef] 42. Hopwood, C.J.; Bleidorn, W.; Schwaba, T.; Chen, S. Health, environmental, and animal rights motives for vegetarian eating. PLoS ONE 2020, 15, e0230609. [CrossRef] 43. Izmirli, S.; Phillips, C.J. The relationship between student consumption of animal products and attitudes to animals in Europe and Asia. Br. Food J. 2011, 113, 436–450. [CrossRef] 44. Kayser, M.; Nitzko, S.; Spiller, A. Analysis of Differences in Meat Consumption Patterns. Int. Food Agribus. Manag. Rev. 2013, 16, 43–56. 45. Lea, E.; Worsley, A. Benefits and barriers to the consumption of a vegetarian diet in Australia. Public Health Nutr. 2003, 6, 505–511. [CrossRef] 46. Lea, E.; Worsley, A. What proportion of South Australian adult non-vegetarians hold similar beliefs to vegetarians? Nutr. Diet. 2004, 61, 11. 47. Lentz, G.; Connelly, S.; Mirosa, M.; Jowett, T. Gauging attitudes and behaviours: Meat consumption and potential reduction. Appetite 2018, 127, 230–241. [CrossRef] [PubMed] 48. Lindeman, M.; Sirelius, M. Food choice ideologies: The modern manifestations of normative and humanist views of the world. Appetite 2001, 37, 175–184. [CrossRef] [PubMed] 49. Mullee, A.; Vermeire, L.; Vanaelst, B.; Mullie, P.; Deriemaeker, P.; Leenaert, T.; De Henauw, S.; Dunne, A.; Gunter, M.J.; Clarys, P.; et al. Vegetarianism and meat consumption: A comparison of attitudes and beliefs between vegetarian, semi-vegetarian, and omnivorous subjects in Belgium. Appetite 2017, 114, 299–305. [CrossRef] [PubMed] 50. Neff, R.A.; Edwards, D.; Palmer, A.; Ramsing, R.; Righter, A.; Wolfson, J. Reducing meat consumption in the USA: A nationally representative survey of attitudes and behaviours. Public Health Nutr. 2018, 21, 1835–1844. [CrossRef] [PubMed] 51. Phillips, C.; Izmirli, S.; Aldavood, J.; Alonso, M.; Choe, B.; Hanlon, A.; Handziska, A.; Illmann, G.; Keeling, L.; Kennedy, M.; et al. An International Comparison of Female and Male Students’ Attitudes to the Use of Animals. Animals 2011, 1, 7–26. [CrossRef] 52. Ploll, U.; Stern, T. From diet to behaviour: Exploring environmental- and animal-conscious behaviour among Austrian vegetarians and vegans. Br. Food J. 2020, 122, 3249–3265. [CrossRef] 53. Povey, R.; Wellens, B.; Conner, M. Attitudes towards following meat, vegetarian and vegan diets: An examination of the role of ambivalence. Appetite 2001, 37, 15–26. [CrossRef] 54. Pribis, P.; Pencak, R.C.; Grajales, T. Beliefs and Attitudes toward Vegetarian Lifestyle across Generations. Nutrients 2010, 2, 523–531. [CrossRef] 55. Ruby, M.B.; Heine, S.J.; Kamble, S.; Cheng, T.K.; Waddar, M. Compassion and contamination. Cultural differences in vegetarianism. Appetite 2013, 71, 340–348. [CrossRef] [PubMed] 56. Schösler, H.; de Boer, J.; Boersema, J.J.; Aiking, H. Meat and masculinity among young Chinese, Turkish and Dutch adults in the Netherlands. Appetite 2015, 89, 152–159. [CrossRef] [PubMed] 57. Siegrist, M.; Hartmann, C. Impact of sustainability perception on consumption of organic meat and meat substitutes. Appetite 2019, 132, 196–202. [CrossRef] [PubMed] 58. Spencer, E.H.; Elon, L.K.; Frank, E. Personal and Professional Correlates of US Medical Students’ Vegetarianism. J. Am. Diet. Assoc. 2007, 107, 72–78. [CrossRef] 59. Verain, M.C.; Dagevos, H.; Antonides, G. Sustainable food consumption. Product choice or curtailment? Appetite 2015, 91, 375–384. [CrossRef] [PubMed] 60. Asvatourian, V.; Craig, T.; Horgan, G.; Kyle, J.; Macdiarmid, J. Relationship between pro-environmental attitudes and behaviour and dietary intake patterns. Sustain. Prod. Consum. 2018, 16, 216–226. [CrossRef] 61. Bryant, C.J. We Can’t Keep Meating Like This: Attitudes towards Vegetarian and Vegan Diets in the United Kingdom. Sustainability 2019, 11, 6844. [CrossRef] Int. J. Environ. Res. Public Health 2023, 20, 286 24 of 25 62. Clonan, A.; Wilson, P.; Swift, J.A.; Leibovici, D.G.; Holdsworth, M. Red and processed meat consumption and purchasing behaviours and attitudes: Impacts for human health, animal welfare and environmental sustainability. Public Health Nutr. 2015, 18, 2446–2456. [CrossRef] 63. de Boer, J.; Schösler, H.; Boersema, J.J. Climate change and meat eating: An inconvenient couple? J. Environ. Psychol. 2013, 33, 1–8. [CrossRef] 64. de Boer, J.; de Witt, A.; Aiking, H. Help the climate, change your diet: A cross-sectional study on how to involve consumers in a transition to a low-carbon society. Appetite 2016, 98, 19–27. [CrossRef] 65. de Boer, J.; Aiking, H. Prospects for pro-environmental protein consumption in Europe: Cultural, culinary, economic and psychological factors. Appetite 2018, 121, 29–40. [CrossRef] [PubMed] 66. De Groeve, B.; Bleys, B. Less Meat Initiatives at Ghent University: Assessing the Support among Students and How to Increase It. Sustainability 2017, 9, 1550. [CrossRef] 67. Ginn, J.; Lickel, B. A Motivated Defense of Meat: Biased Perceptions of Meat’s Environmental Impact. J. Soc. Issues 2019, 76, 12362. [CrossRef] 68. Hunter, E.; Röös, E. Fear of climate change consequences and predictors of intentions to alter meat consumption. Food Policy 2016, 62, 151–160. [CrossRef] 69. Latvala, T.; Niva, M.; Mäkelä, J.; Pouta, E.; Heikkilä, J.; Kotro, J.; Forsman-Hugg, S. Diversifying meat consumption patterns: Consumers’ self-reported past behaviour and intentions for change. Meat Sci. 2012, 92, 71–77. [CrossRef] 70. Lea, E.; Worsley, A. Australian consumers’ food-related environmental beliefs and behaviours. Appetite 2008, 50, 207–214. [CrossRef] 71. Mäkiniemi, J.-P.; Vainio, A. Barriers to climate-friendly food choices among young adults in Finland. Appetite 2014, 74, 12–19. [CrossRef] 72. Malek, L.; Umberger, W.J.; Goddard, E. Committed vs. uncommitted meat eaters: Understanding willingness to change protein consumption. Appetite 2019, 138, 115–126. [CrossRef] 73. Pohjolainen, P.; Tapio, P.; Vinnari, M.; Jokinen, P.; Räsänen, P. Consumer consciousness on meat and the environment—Exploring differences. Appetite 2016, 101, 37–45. [CrossRef] 74. Akaichi, F.; Revoredo Giha, C.; Glenk, K.; Gil, J.M. How Consumers in the UK and Spain Value the Coexistence of the Claims Low Fat, Local, Organic and Low Greenhouse Gas Emissions. Nutrients 2020, 12, 120. [CrossRef] [PubMed] 75. Tobler, C.; Visschers, V.H.; Siegrist, M. Eating green. Consumers’ willingness to adopt ecological food consumption behaviors. Appetite 2011, 57, 674–682. [CrossRef] [PubMed] 76. Truelove, H.B.; Parks, C. Perceptions of behaviors that cause and mitigate global warming and intentions to perform these behaviors. J. Environ. Psychol. 2012, 32, 246–259. [CrossRef] 77. Vanhonacker, F.; Van Loo, E.J.; Gellynck, X.; Verbeke, W. Flemish consumer attitudes towards more sustainable food choices. Appetite 2013, 62, 7–16. [CrossRef] [PubMed] 78. Siegrist, M.; Visschers, V.; Hartmann, C. Factors influencing changes in sustainability perception of various food behaviors: Results of a longitudinal study. Food Qual. Prefer. 2015, 46, 33–39. [CrossRef] 79. Boyle, J.E. Becoming Vegetarian: The Eating Patterns and Accounts of Newly Practicing Vegetarians. Food Foodways 2011, 19, 314–333. [CrossRef] 80. Fox, N.; Ward, K. Health, ethics and environment: A qualitative study of vegetarian motivations. Appetite 2008, 50, 422–429. [CrossRef] [PubMed] 81. Graça, J.; Calheiros, M.M.; Oliveira, A. Moral Disengagement in Harmful but Cherished Food Practices? An Exploration into the Case of Meat. J. Agric. Environ. Ethic 2014, 27, 749–765. [CrossRef] 82. Guerin, K. Where’s the Beef? (With Vegans): A Qualitative Study of Vegan-Omnivore Conflict. Bachelor’s Thesis, University of Colorado at Boulder, Boulder, CO, USA, 2014. 83. Happer, C.; Wellesley, L. Meat consumption, behaviour and the media environment: A focus group analysis across four countries. Food Secur. 2019, 11, 123–139. [CrossRef] 84. Hoek, A.C.; Pearson, D.; James, S.W.; Lawrence, M.A.; Friel, S. Shrinking the food-print: A qualitative study into consumer perceptions, experiences and attitudes towards healthy and environmentally friendly food behaviours. Appetite 2017, 108, 117–131. [CrossRef] 85. Lea, E.; Worsley, A.; Crawford, D. Australian Adult Consumers’ Beliefs About Plant Foods: A Qualitative Study. Health Educ. Behav. 2005, 32, 795–808. [CrossRef] [PubMed] 86. Macdiarmid, J.I.; Douglas, F.; Campbell, J. Eating like there’s no tomorrow: Public awareness of the environmental impact of food and reluctance to eat less meat as part of a sustainable diet. Appetite 2016, 96, 487–493. [CrossRef] [PubMed] 87. McEachern, M.G.; Schröder, M.J.A. The Role of Livestock Production Ethics in Consumer Values Towards Meat. J. Agric. Environ. Ethic 2002, 15, 221–237. [CrossRef] 88. Mycek, M. Meatless meals and masculinity: How veg* men explain their plant-based diets. Food Foodw. 2018, 26, 223–245. [CrossRef] 89. Mylan, J. Sustainable Consumption in Everyday Life: A Qualitative Study of UK Consumer Experiences of Meat Reduction. Sustainability 2018, 10, 2307. [CrossRef] Int. J. Environ. Res. Public Health 2023, 20, 286 25 of 25 90. Spendrup, S.; Röös, E.; Schütt, E. Evaluating ConsumerUnderstanding of the Swedish Meat Guide—A Multi-layered Environ- mental Information Tool Communicating Trade-offs When Choosing Food. Environ. Commun. 2017, 13, 87–103. [CrossRef] 91. Austgulen, M.H.; Skuland, S.E.; Schjøll, A.; Alfnes, F. Consumer Readiness to Reduce Meat Consumption for the Purpose of Environmental Sustainability: Insights from Norway. Sustainability 2018, 10, 3058. [CrossRef] 92. Scott, E.; Kallis, G.; Zografos, C. Why environmentalists eat meat. PLoS ONE 2019, 14, e0219607. [CrossRef] 93. Sanchez-Sabate, R.; Badilla-Briones, Y.; Sabaté, J. Understanding Attitudes towards Reducing Meat Consumption for Environ- mental Reasons. A Qualitative Synthesis Review. Sustainability 2019, 11, 6295. [CrossRef] 94. Sanchez-Sabate, R.; Sabaté, J. Consumer Attitudes Towards Environmental Concerns of Meat Consumption: A Systematic Review. Int. J. Environ. Res. Public Health 2019, 16, 1220. [CrossRef] Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). 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