Understanding Attitudes towards Reducing Meat Consumption for Environmental Reasons. A Qualitative Synthesis Review

Abstract

Meat-based diets are the norm in Western societies. This is a problem because meat production is a major contributor to global warming and environmental degradation. Despite the urgency to reduce meat consumption, quantitative studies have shown that there is only a small minority of consumers aware of the meat environmental impact, willing to halt or reduce meat intake for ecological reasons, or who have already stopped or reduced meat consumption because of environmental concerns. We conducted a qualitative synthesis reviewing studies that looked at attitudes towards changing meat consumption. Our focus was on the behavioral change process: Awareness, willingness, and change, aiming to enhance the current understanding of people’s attitudes towards reducing meat consumption due to environmental concerns. The studies reviewed show that consumer awareness is hindered by beliefs about food, meat, and personal behavior. Nutrition, health, and taste were found to be both enablers and barriers with regard to willingness. Vegetarians and vegans perceive the environment as simply another reason, among others, to maintain a meatless diet. Based on these results, we offer recommendations for future dietary public health interventions, and for future research endeavors on this topic. This review employed a meta-aggregative approach and partially followed the Joanna Briggs Institute methodology for systematic reviews of qualitative evidence.

1. Introduction

Meat consumption is a major contributor to global warming and environmental degradation [1,2,3,4,5]. The livestock industry pollutes and depletes fresh water, contributes to the loss of biodiversity, and is a major source of anthropogenic greenhouse gas emissions [1]. Since the worldwide demand for meat is increasing due to rising incomes, growing populations, and other sociocultural factors [1,6,7], the health and well-being of the global population are every day at greater risk. A recent assessment estimates that climate change will increase future risks of armed conflict [8], while the recently published EAT-Lancet report “Food in the Anthropocene” [9] warns that unless red meat consumption is significantly reduced, it will be impossible to feed, in a healthy and sustainable manner, an estimated global population of 10 billion people by 2050. The latest Intergovernmental Panel on Climate Change (IPCC) special report stated that, given the current scientific evidence, there is a high degree of confidence in the potential of reducing animal-based product consumption to achieve significant mitigation of climate change [10]. The double food and environmental pyramid by the Barilla Center showcases at a glance this link between nutritional and environmental aspects of food [11].

Meat-based diets are the norm in Western societies. In countries like the United States and the United Kingdom, vegetarians account for less than 5% of their respective populations [12]. Rationalizations of meat consumption in the West are synthesized in the 4Ns: Meat is natural—it is what our biology has come to crave in the evolutionary process, eating meat is normal—it is a sociocultural practice and expectation in civilized societies, meat is necessary for humans to be healthy, and meat is nice—animal protein is tasty [13]. Consumption habits, culinary traditions, and what sociologists call cultural repertoires (culturally available unarticulated instructions loaded with values and understandings that guide people’s actions) are also important factors to explain meat intake [14,15]. Given all these socio-cultural factors, it is clear that changing the current Western meat consumption pattern is challenging [16].

The Transtheoretical Model (TTM) of health behavior change [17] describes the behavioral change process as a three-stage progression that comprises awareness (precontemplation), willingness (contemplation and preparation), and change (action, maintenance, and termination). This process of change can only occur with the adoption of a positive attitude based on reasons and motivations [17]. Since climate change and environmental sustainability are pressing reasons or motivations to reduce meat intake [9], a growing body of research is looking at the influence of environmental concerns in Westerners’ meat consumption. Systematic reviews of the quantitative evidence only have shown that environmental motives have a weak influence on meat consumption attitudes [18,19]. People are rarely aware of the meat environmental toll. They underestimate its impact compared with other behaviors or activities. Only a minority seem willing to alter meat consumption because of the environment, but even they would rather adopt other strategies to counter climate change. Consequently, only a small minority has altered its meat-eating patterns because of the environment, a motive more appealing to vegans and flexitarians than vegetarians. Those most aware and positively influenced by environmental concerns are female, young, and meat-reducers.

Quantitative studies generally provide little or no information on why a person is aware, or willing, or why they made a change in meat consumption habits because of the environment. Previous systematic reviews on this topic have acknowledged some of these limitations. For example, they have called for more in-depth studies on willingness [18], and for exploring the cultural and social factors attached to meat that impact willingness and dietary change [19]. Still, many more questions can be asked to qualitative evidence. Why are consumers not aware that meat consumption degrades the environment? Is it because they simply have not been educated on the topic? Could it be instead that their beliefs, perceptions, reasons or motivations conflict with the scientific evidence on meat consumption and the environment? Do they actually understand what environmentally-friendly food is? Similar questions can be raised regarding willingness. Is the low willingness to alter meat consumption for environmental reasons attributable only to their low awareness? Do environmental motives affect in any way the 4Ns (natural, normal, necessary, nice)? Is there something that can be done to increase willingness beyond educating people on the meat environmental impact either in a rational or emotional fashion? Regarding those who have changed their meat dietary patterns because of the environment, it is necessary to know how consumers understand their behavioral change. Do they see it as a must or as simply another way to help the environment? Why did non-ecologically oriented people alter their meat consumption because of the environment?

Syntheses of qualitative evidence have proved useful to complement and better interpret quantitative systematic reviews [20]. By qualitative review we mean “the synthesis or amalgamation of individual qualitative research reports (commonly called “primary research reports”) that relate to a specific topic or focus in order to arrive at a new or enhanced understanding about the phenomenon under study” [21]. The value of “enhanced understanding” that qualitative evidence synthesis can provide is already widely recognized across the natural and social sciences within the evidence-based approach [20,22]. The Cochrane Collaboration Qualitative Methods Group, the Health Development Agency, The Economic and Social Research Council, and The Joanna Briggs Institute have made significant efforts to facilitate the use of qualitative evidence synthesis in disciplines such as public health and education, among others [20,23]. The efforts of these institutions are driven by the fact that qualitative evidence syntheses have the potential to contribute both to the scientific community and different kinds of institutions. Qualitative evidence synthesis may, indeed, serve to inform the creation of research instruments by identifying the significant characteristics of a phenomenon, as well as to develop actionable knowledge that can inform both policy and practice [20].

The purpose of this qualitative evidence synthesis is to enhance our understanding of attitudes towards reducing meat consumption because of environmental concerns. We expect to get a better grasp on the nature of individual and group awareness, willingness and actual change of dietary habits to protecting the planet. Hoping to inform both future dietary public health interventions in adopting healthy and sustainable diets, and future research endeavors on this topic, we have looked at what qualitative studies have to say regarding the already named stages of the behavioral change process: Awareness, willingness, and change. Our research question was: What are the enablers and barriers to increase awareness, willingness, and change when consumers are prompted to reduce meat consumption because of environmental concerns? A preliminary search of PROSPERO, MEDLINE, the Cochrane Database of Systematic Reviews, the JBI Database of Systematic Reviews and Implementation Reports was conducted and no current or ongoing qualitative evidence syntheses on this topic were identified.

2. Materials and Methods

2.1. Search Strategy

The articles considered for this qualitative evidence synthesis were identified through a literature search of the Web of Science (WOS) Core Collection conducted in March 2018. The search was aimed at finding studies on people’s attitudes towards meat consumption in relation to planetary health. For each subtopic (awareness, willingness, and change), a separate query was conducted. Strings and search terms used to retrieve relevant literature are detailed in

Table 1. Search strings and terms.

Term	Operator	Term	Operator	Term
AWARENESS
consumer attitudes	AND	Meat	AND	climate change
				GHG emissions
consumer perceptions				global near/2 warming
people attitudes		livestock		environment
people perceptions				water near/3 use
				land near/3 use
WILLINGNESS
consumer willingness	AND	“plant-based” near/3 diet	AND	climate change
		vegetarian diet		GHG emissions
		vegan diet		global near/2 warming
people willingness		meatless diet		environment
				water near/3 use
		“less meat”		land near/3 use
CHANGE
“Plant-based” near/3 diet	AND	reason	AND	environment
vegetarian near/3 diet
vegan near/3 diet				climate change
meatless near/3 diet		motivation
“less meat” near/3 consumption				global warming
vegetarians
vegans

A single and separate query with one term of each column was created. A total of 48 search queries for awareness were created. A total of 60 search queries for willingness were created, a total of 42 search queries for change were created.

.

Two authors conducted the screening process independently in order to reduce bias. For each subtopic, a three-step procedure was performed. First, titles, abstracts, and keywords were screened. Relevant articles on either awareness, willingness, and/or change were imported to Zotero reference manager. Second, saved references were read in full with a twofold purpose: (1) To make sure that they met the inclusion criteria (Figure 1) and (2) to identify in their cited references section new articles not yielded by the WOS search. Third, these first two steps were repeated until citation redundancy was achieved. When a reference was declared eligible by one reviewer only, the two reviewers reached an agreement on its inclusion or exclusion. Flow charts of this process can be found in Appendix D.

2.2. The Meta-Aggregative Approach

There are many methods for conducting qualitative evidence synthesis [21]. All of them entail various degrees of interpretation and aggregation, but in each method, either interpretation or aggregation is more prominent than the other [21]. This review uses a meta-aggregative approach, a method “designed to model the Cochrane process of systematic reviews summarizing results of quantitative studies while being sensitive to the nature of qualitative research and its traditions” [21]. The focus of this approach is the practical consequences of the generalizations that can be drawn from the summary of common and competing findings. In other words, this method aims to produce the knowledge necessary to recommend actions in the field of study [21]. In the present case, our goal is to produce knowledge to make future diet-oriented public health intervention programs more effective, as well as to inform future research on consumers’ attitudes towards meat intake reduction.

The process of meta-aggregation conducted followed, with minor variations, the Joanna Briggs Institute (JBI) methodology for systematic reviews of qualitative evidence [23]. It was conducted with the assistance of the JBI software called System for the Unified Management, Assessment, and Review of Information (SUMARI), which was designed to assist researchers and practitioners in conducting systematic reviews [24]. The JBI methodology includes developing a research question, conducting a literature search, doing a critical appraisal of selected studies, extracting the findings, categorizing them and, finally, generating synthesized findings [25]. The JBI SUMARI critical appraisal instrument evaluates the coherence between the theory, the methodology, the research question, and the representation of data and its interpretation, as well as identifying how the researchers’ values and beliefs might influence the study. Research ethical procedures are also evaluated [23]. It was decided that, since a small number of studies were identified, all the studies would be included regardless of their quality. Even so, all selected studies were assessed by one of the authors (see Appendix B). The JBI protocol also recommends contacting authors of papers reviewed in order to ask for clarification when necessary. For this review, no further clarification was deemed necessary.

2.3. Data Extraction

Data extraction from the selected papers was carried out by two independent reviewers using the JBI-SUMARI extraction instrument [23] (see Appendix A). Extracted data included details about the population, context, geographical location, study methods, and the phenomena of interest relevant to the review questions. Findings and their illustrations were extracted by one reviewer only, since the meta-aggregative approach does not require two independent reviewers for this procedure. At this stage, the reviewer must stay as close as possible to the themes listed by the original authors and avoid interpretation of them [21]. A finding is defined as “a verbatim extract of the author’s analytic interpretation of their results or data”. An illustration is defined as “a direct quotation of a participant‘s voice, field-work observation or other supporting data from the paper” [23].

The JBI method requires the assignment of a credibility level for each finding depending on weather illustrations are provided in support of findings, and on how clearly an illustration supports a finding. Thus, “unequivocal” findings are clearly supported by the accompanying illustrations, “credible” findings come with an illustration lacking clear association with it, and “unsupported” findings do not provide supporting illustrations [23]. In the present review, however, only two levels of credibility are considered: “unequivocal” (U) for findings that come with illustrations and “credible” (C) for findings without illustrations. Two reasons justify this methodological decision. First, journal editors generally restrict the number of words per article, forcing authors to leave out illustration data. Secondly, while the JBI method allows the consideration of unpublished results [23], this review only considered published studies indexed by the Web of Science. Thus, it is assumed the papers included in this review went through a peer-review process that checked the credibility of the findings.

2.4. Data Synthesis

Qualitative research findings were pooled using JBI SUMARI with the meta-aggregation approach [23]. This involved the aggregation or synthesis of findings to generate a set of statements that represent that aggregation, through assembling the findings and categorizing these findings on the basis of similarity in meaning. These categories were then subjected to a synthesis in order to produce a single comprehensive set of synthesized findings. These findings, then, should broaden our understanding of the relationship between environmental concerns and meat consumption and thus, inform future diet-oriented public health interventions and research efforts. Categories are defined as “a brief description of a key concept arising from the aggregation of two or more like findings and is accompanied by an explanatory statement that conveys the whole, inclusive meaning of a group of similar findings.” [23]. A synthesized finding is “an overarching description of a group of categorized findings” [23]. This data synthesis process was conducted by two reviewers.

3. Results

3.1. Studies Included and their Characteristics

Following the inclusion criteria (Figure 1), a total of 10 studies were identified on either awareness of the meat impact on the planet, and/or willingness to stop or reduce meat consumption for environmental reasons, and/or consumers who have already altered their meat intake for ecological concerns. The number of studies identified and considered in this review is the minimum recommended to conduct a meta-synthesis [26].

The articles on awareness and/or willingness share a common phenomenon of interest, namely, people’s perceptions of, and potential dietary response to the meat environmental impact. Their samples include a total of 328 participants, from teenagers to elders, defined as meat eaters. Very few vegetarians took part in a couple of studies. Reviewed papers on motivations that brought actual change focus only on vegetarians and vegans. We did not find any study that explored the reasons and motivations for consumers becoming flexitarians or simply reducing their meat consumption due to concerns for the environment. Four out of the five papers on dietary change explored the contexts and motivations for either becoming a vegetarian/vegan or keeping a meatless diet. The fifth article explored possible emotional relationships between vegetarianism and death. We considered it relevant because the research process included an inquiry on the reasons for adopting a vegetarian/vegan diet. These investigations on dietary change had a total of 301 vegetarian/vegan and former vegetarian participants aged from 14 to 85 years old. See Appendix A for the characteristics of the included studies.

Regarding methodology, a clear majority of the reviewed studies employed thematic analysis. Two of them worked with grounded theory. Focus groups were the most common way to obtain data. Three research projects interviewed or surveyed participants over the internet. The geographic context of the studies was very limited. All articles but one studied English-speaking populations mainly from the United Kingdom and Oceania. Only four articles mentioned some kind of covariates effects. Since reported covariates vary, or their effects are contradictory across studies, it was not possible to extract patterns of influence worthy of reporting. Overall, reviewed studies are of medium to high quality (see Appendix B).

3.2. Awareness

Figure A1 and Figure A2 (see Appendix E) show the aggregative process from general findings extracted from four papers to synthesized findings on people’s awareness of the environmental impact of meat production and consumption. Extracted findings and illustrations are reported in Appendix C.

Figure A1 presents the findings and categories that sustain the first synthetized finding on awareness: Consumers do not bear in mind that food in itself has an environmental dimension. Extracted findings show that consumers believe that unsustainable food has to do with food production and distribution activities like deforestation, pollution, transport, and excessive packaging [27,28,29,30], for example, but not with the type of food in itself, be it animal or vegetable. In fact, we found evidence that consumers are confused or simply ignorant when it comes to defining environmentally friendly foods [28]. This is consistent with findings about consumers not thinking of the environment when making food purchase decisions [27,28,30]. Therefore, we classified all these findings into three categories: (1) Consumers attribute food environmental impact to food systems activities only, (2) lack of clarity among consumers on what ecological food is, and (3) in the same way that consumers consider price and healthiness, among others, food environmental impact is not a food property for them. These three categories have in common an understanding or conceptualization of food as detached from the environment.

If the first synthetized finding on awareness has to do with food in general, the second, presented in Figure A2, is exclusively about meat: Consumers’ perceptions of meat consumption are a barrier for them to acknowledge or accept that reducing meat intake would alleviate negative impacts on the environment. In other words, consumers do not seem ready to fully integrate the idea that a sustainable diet must have little or no meat. Extracted findings show that people believe it to be irrelevant, or they disagree that reducing their own meat intake would significantly impact the environment [29]. Some consumers associate the meat environmental impact with cattle methane gas and deforestation only [27,29], making no link between meat consumption and climate change [27,28,29,30]. In general, they have a romanticized image or conception of meat, imagining animals freely grazing in the field and not in packed stables typical of intensive farming [28]. Still, some people are sensitive to animal welfare issues [28]. These findings were classified into three categories: (1) Disbelief that altering personal meat consumption can alleviate climate change, (2) meat environmental impact restricted to methane gas and deforestation, and (3) consumers have an overall good perception of meat.

3.3. Willingness

Four papers on people’s willingness to reduce meat consumption because of the environment were identified and reviewed. Extracted findings and illustrations can be found in Appendix C. Figure A3, Figure A4, Figure A5 and Figure A6 (see Appendix E) show the aggregative process from general findings to a total of four synthesized findings.

The first synthesized finding is that environmental reasons and motives can be an enabler for reducing meat consumption to a certain extent. Extracted findings indicate that environmental concerns can prompt consumers to minor reductions in meat intake [31]. Some people, though, believe more scientific evidence is needed on the environmental impact of meat before they would make a dietary decision [29]. These findings were classified into two very similar categories summarized here in a sentence: Environmental concerns may motivate reductions in meat intake but not significantly alter meat-eating patterns.

The second synthesized finding is that sociocultural, culinary, and physiological reasons are barriers for consumers to reduce meat consumption on environmental concerns. Under the category “barriers to a large meat intake reduction,” we grouped extracted findings that show that consumers argue social reasons, tradition, and lack of culinary skills to resist a substantial reduction of meat in their diets [30]. In fact, some consumers perceived a 70% meat reduction to be the same as becoming vegetarians, something they were not willing to do [30]. Extracted findings from papers that simply asked consumers about their willingness to reduce their meat intake without specifying the amount were grouped under the category “barriers to an indeterminate meat intake reduction”. Again, sociocultural [27,29,31] and culinary [29,31] reasons were barriers. Dietary habits also prompt resistance to meat intake reduction [27,29,31]. Other findings have to do with physiological reasons [27,29,31], like achieving satiety and the pleasure of eating meat. These two barriers might be reinforced by the finding that consumers believe that a proper meal must have meat [30]. Consumers also may refuse to curtail meat consumption to mitigate climate change because they say that, driven by other reasons, they have already reduced their meat consumption [29]. Other consumers may resist a reduction in meat consumption for no reason whatsoever [27], or they choose to change other behaviors to help the environment instead of altering their intake of meat [29].

The third synthesized finding captures the ambiguous potential of health, nutrition, taste, and economic reasons to act as both enablers or barriers in consumers’ willingness to reduce meat consumption because of the environment. Extracted findings show that some consumers may perceive a reduction of meat as healthy and nutritionally sound [29,31], while others as unhealthy and nutritionally unsound [27,29,30,31]. In the same way, some consumers argued the lack of palatable alternatives to meat as a resistant factor to changing meat consumption [27,29,30,31], while others, faced with pictures of tasty looking vegetarian dishes by the research team, were inclined to eat less meat [31]. Extracted findings regarding the influence of economic reasons show that pricey meat prompts lower consumption of it [29,30,31]. However, consumers associate the lack of meat in their main daily meals with poverty [30].

The fourth synthetized finding is that consumers demand nutritional and culinary education in order to adopt a low or meatless diet to alleviate harm to the environment. People have difficulties imagining an alternative diet with low or no meat to their current dietary patterns [29,30,31]. Having understood the pressure of environmental concerns, they demand nutritional and culinary education to adopt a sustainable diet [30]. Consumers do not appreciate dietary interventions focused on what not to eat. They would rather listen to advice on how to lead a healthy and tasty low or meatless diet [30].

3.4. Change

A total of five articles were identified and reviewed regarding meat reduction or avoidance due to environmental concerns. All reviewed articles studied vegetarians and/or vegans. No qualitative evidence has been found regarding people who simply reduced their meat intake because of the environment. Extracted findings and illustrations can be found in Appendix C. Figure A7 and Figure A8 (see Appendix E) show the aggregative process from general findings to a total of two synthesized findings.

The first synthesized finding states that environmental concerns can be both a trigger for adopting [32,33,34], and reinforcement for sustaining [34,35,36], a meatless diet. Even though only for a minority, there are consumers for whom environmental reasons were the initial motivation to become vegetarian. In some cases, environmental motivations prompted vegetarians to go vegan [35]. Other extracted findings were grouped under the category “environmental concerns as part of a non-ecological web of motivations to adopt or sustain a vegetarian diet”. These findings show that care for the environment is another reason to justify a vegetarian diet already adopted because of health or ethical reasons, or one of many reasons to avoid animal products. One paper reported that some consumers argued that the environmental inefficiency of meat production contributed to world hunger, making the adoption of a vegetarian diet a human rights issue [36].

The second synthesized finding is that consumers involved in environmentalism or that simply love nature consider a meatless diet just another behavior to care for the environment. Extracted findings show that love for nature can prompt consumers to become vegetarian [33]. Other consumers see a meatless diet as a way to reinforce their commitment to life on Earth [34]. People may also adopt a vegetarian diet as a consequence of their environmentally friendly lifestyle [35]. However, one study on reasons for leaving vegetarianism showed that among ex-vegetarians, the majority had originally adopted a vegetarian diet because of the environment. It seems that with time, they opted for other ways to alleviate the environmental impacts, such as eating limited amounts of meat or only organic meat [32].

4. Discussion

In this qualitative evidence synthesis, we looked at three groups of behavior stages of change regarding meat consumption: (1) Awareness, which refers to subjects in the precontemplation stage, (2) willingness, which refers to individuals in the contemplation and preparation stages, and (3) change, which includes people in the action, maintenance, and termination stages [17]. Below, we discuss how the reviewed qualitative evidence complements the quantitative studies systematically reviewed on awareness, willingness, and change [19].

Quantitative research on awareness has shown that aware consumers are a minority, that they underestimate or ignore the potential of reducing meat consumption to mitigate climate change, and that consumers ignore that a meatless diet is more environmentally friendly than one including meat [19]. Reviewed qualitative evidence reaffirms these findings, and synthesized findings add profundity to them. As long as consumers perceive food as detached from the environment, it is going to be hard for them to, first, make sense of the fact that food in itself, apart from transport and packaging, has an environmental impact, and, second, start distinguishing foods according to their environmental impact. This is clearly a barrier to increase awareness, and it may help explain why sustainability messages in favor of meat reduction are difficult for consumers to understand [37]. A second barrier is that consumers have an overall positive image of meat that does not seem to be affected by scientific evidence regarding the environmental degradation caused by meat production. In other words, the values consumers attach to meat trump the value of environmental protection and the value to mitigate climate change. All this indicates that the problem is not (only) a matter of knowledge but a matter of internal dispositions and mental frameworks that could make it hard for consumers to learn and accept scientific evidence regarding the meat environmental impact. De Boer and Aiking [37] have recently proposed several communication strategies based on the psychological theory of frames that may help bridge mental frameworks against meat intake reduction.

Quantitative studies on willingness have shown that consumers willing to reduce their meat intake to alleviate the environment are a minority. Among suggested strategies to curb climate change, meat curtailment is the least preferred [19]. The reviewed qualitative evidence reaffirms these findings and sheds further light. In general, there is a strong resistance to alter meat consumption because sociocultural, culinary, and physiological reasons trump environmental motives. This finding is consistent with the experience of actual meat-reducers. A qualitative study conducted in the UK demonstrated that meat reduction is conditioned by determinants beyond consumers’ ethical stance towards the environment or animal welfare. Social pressure and understandings of nutrition constrain consumers’ meat-reducing practices [38]. This might explain why consumers would rather adopt any other strategy to counter climate change before eating less meat: People have many strong reasons to continue eating meat. However, the reviewed qualitative evidence indicates that there are several important reasons, like health, nutrition, and taste, that can be allies of environmental motives in increasing consumers’ willingness to reduce meat intake. Consumers who have an already positive image of low-meat diets may find in environmental protection a trigger to make a dietary change. This could mean that out of the aforementioned 4Ns, the Ns for necessity (need to eat meat to be healthy) and nice (meat tastes good) have the potential to become strong allies of meat intake reduction if consumers understand that planetary health is essentially linked to human health, and if consumers are helped to generate positive taste expectations for plant-based meals, as the results of this review show and another review suggested [39]. In this sense, probably the most useful finding is what could be consumers’ fundamental reason for unwillingness to alter their meat consumption: Their acknowledged lack of nutritional and culinary knowledge that hinders them from being able to imagine an alternative way of eating with little or no meat. This barrier has also been identified by a review on “capability, opportunity, and motivation” to reduce meat intake and adopt plant-based diets [39], and by a review of influence factors on meat reduction [40]. Given the fact that consumers demand nutritional and culinary education, increasing willingness might be less a matter of strong reasons to resist meat intake reduction and more a matter of knowledge and practical skills to actually adopt an appealing low or meatless diet. Stoll-Kleemann and Schmidt [40] have also argued for the need to stop underestimating the importance of providing food-related skills (i.e., how to cook, know where to find affordable and tasty meat-free food) in getting consumers to reduce meat intake.

Quantitative evidence on change has shown that environmental concerns are the main reason to adopt a meatless diet for only a minority among the general population. The influence of environmental motives to drive change is more prevalent among meat-reducers or flexitarians than among vegetarians or vegans [19]. In light of quantitative and qualitative evidence on willingness, these results are a logical consequence. They are also consistent with the fact that the most prevalent reasons to become vegetarian [35,36,41,42,43] or reduce meat consumption [44] are health and animal welfare.

The reviewed qualitative evidence on change studied only vegetarians and vegans, and not meat-reducers or flexitarians. Still, it may prove useful to explain why environmental protection is a more prevalent primary driver among meat-reducers or flexitarians than among vegetarians and vegans when it comes to change. Qualitative evidence shows that for the majority of vegetarians and vegans, environmental concerns are a secondary or subsidiary reason to health or animal welfare motives. For them, the environment is less a motive to change and more a reason to sustain and further justify their meatless diet. In the case of flexitarians, the lack of qualitative evidence on change [38,45] makes it difficult to understand how environmental concerns influence their dietary choices. Based on current evidence on flexitarian awareness and willingness, however, we hypothesize that environmental concerns have a similar degree of influence in both vegetarians/vegans and flexitarians. In other words, we suggest that both groups of people value the environment arguably the same. The reason why environmental concerns are more prevalent drivers for change among flexitarians than vegetarians may have to do with attributed value to animal welfare and the understanding of what constitutes a healthy diet. While many vegetarians and vegans place a high value on animal welfare to the point of adopting a countercultural diet in the Western context, flexitarians would give a low value to such ethical concerns. Regarding health, vegetarians associate it to a meatless diet while flexitarians to a diet with meat, as the reviewed qualitative evidence and other quantitative evidence [46] has shown. This would support the idea that flexitarians, indifferent to animal welfare and convinced that a certain amount of meat is indispensable to meet human nutritional needs, may find in environmental protection the only driver to eat less meat. Both a review on the psychology of vegetarianism that also considered the literature on flexitarians, and another review on influence factors for reducing meat consumption reinforce this hypothesis [40,47].

A general recommendation for future research on awareness, willingness, and change is to address the geographical and cultural limitations of the reviewed studies. As noted above, they were conducted in North America, the United Kingdom, Australia, and New Zealand only. Since quantitative evidence has already shown that willingness is significantly higher in southern European countries than in northern ones [48], qualitative research is necessary in order to understand why that is the case. Moreover, since meat consumption is increasing in the low and medium-income countries of Asia and Latin America [1,6], qualitative research in these countries is urgent in order to stop such increase before meat consumption reaches the level of the high-income countries. Another limitation of the reviewed qualitative evidence is that cultural and ethnic factors were rarely taken into account in the research design and sample selection. Given that quantitative evidence has shown that there are differences in willingness across ethnicities inhabiting the same country [49], qualitative studies could further illuminate the role of different cultures in awareness, willingness, and change. Finally, since several reviewed studies are a few years old, and environmental concerns have received abundant media attention in the last two years, consumer attitudes towards meat consumption because of the environment might have changed.

Recommendations

The findings of this review suggest the following recommendations for future public health dietary interventions, and for future research on awareness, willingness, and change.

Public health interventions on awareness:

• Prepare consumers to understand that meat has an environmental impact by (1) informing that food, in general, has an environmental dimension, (2) addressing the positive image of meat consumption among consumers (strategies need to be found in order to persuade consumers that meat is not as good as they believe, (3) addressing skepticism towards the effectiveness of personal dietary change.

Scientific research on awareness:

• Investigate consumers’ information sources. It would be necessary to compare information sources and credibility attributed to them for consumers already aware and not yet aware.
• Research how to overcome consumers’ beliefs and perceptions (barriers) that make it difficult for them to acknowledge the environmental impact of meat.

Public health interventions on willingness:

• Consumers need to feel nutritionally safe and enjoy their meals. Nutritional and culinary education on meatless diets may increase consumers’ willingness to reduce their meat consumption.

Scientific research on willingness:

• Quantitative studies have shown that when prior information about the environmental impact of meat is given, willingness to reduce meat consumption increases. However, this could be attributed to social desirability. It would be necessary to observe if prior nutritional and culinary education would be more effective than prior information in increasing people’s willingness to reduce meat consumption.
• Since health/nutritional, economic, and taste reasons can be both enablers and barriers depending on who is asked, it is necessary to find out the social covariates that correlate with these reasons as enablers and barriers to reduce meat consumption.

Public health interventions on change:

• Inform consumers that a meatless diet is not simply just another behavior to alleviate climate change. Research has shown that it is probably the most effective personal behavior [50,51].
• Link personal and animal health to planetary health (since personal health and animal welfare are the most prevalent motives to become vegetarian).

Scientific research on change:

• Conduct qualitative investigations on meat-reducers and flexitarians.

5. Conclusions

The few qualitative research studies on consumers’ attitudes towards meat consumption in relation to planetary health has proven useful to deepen our understanding of people’s awareness of environmental impact of meat consumption, of consumers’ willingness to eat less meat to alleviate the negative impacts on the environment, and of dietary change motivated by environmental concerns. Awareness is hindered by certain consumers’ beliefs on food, meat, and personal behavior. Thus, public health interventions aimed at increasing awareness should rely less on disseminating information and more on fact-based persuasive communication strategies. Willingness is easily hindered by different reasons and motivations. Therefore, satisfying consumer demands for nutritional and culinary education may significantly increase people’s willingness to help the environment by reducing meat consumption. Change is especially understudied because there is no qualitative evidence on flexitarians. Environmental vegetarians and vegans need further education in order to be aware that giving up meat is not just another behavior to help the environment but the most impactful individual practice.