Sustainability is defined as a guiding principle for how we treat our resources, a normative concept that emphasizes three dimensions of an agenda for the future of our earth: the economic, environmental, and social dimensions (Purvis et al., 2019). The program for action in these dimensions has been outlined by the so-called Brundtland Report (Imperatives, 1987), and further developed into the Sustainable Development Goals (SDGs) and national and regional agendas (United Nations, 2015).

Today, sustainability as a principle of the action sits at the core of a societal discourse on meeting climate change-related global challenges as well as progress and social and cultural transformation (United Nations, 2015). However, the claim that sustainability impregnates all societal areas of action and reflection is still to be met. On the one hand, sustainability is increasingly fundamental in organizations to provide legitimacy, guide the taking of responsibility, and possess a “license to operate” in terms of the acceptance that is granted to an organization by the community (Newig et al., 2013; Rasche et al., 2017; Hurst and Johnston, 2021). On the other hand, sustainability seems to be a highly complex principle with a strong normative and therefore moral character (Vogt, 2010; Vogt and Weber, 2019), which requires comprehensiveness, transparency, proximity, and balance to avoid being (ab)used by organizations and predominantly corporates to replace what was innovation or future orientation a decade ago.

On an individual level, it gets even harder to deal with sustainability as a normative principle, bringing in a certain degree of morality in everyday life choices regarding transportation and mobility, food, or retail (Weder et al., 2019, 2021; Fischer et al., 2021). While sustainable consumption is framed as meeting the needs of the present without compromising the ability of generations in the future to meet their own needs—and thus going back to the first definitions of sustainability (WCED SWS, 1987)-, it is much harder to provide a definition of sustainable consumption practices (Glavi and Lukman, 2007; Balderjahn et al., 2013; Geiger et al., 2018). This leads to well-debated and studied attitude-behavior-gaps (Carrington et al., 2014; White et al., 2019; Kilian and Mann, 2020), and normative influences on food choices (Dowd and Burke, 2013; Zhou et al., 2013; Chekima et al., 2019) and other areas of consumption (see overview in Pristl et al., 2021). In the case of food and meat consumption and production, sustainability concerns, which originally involved the direct impact of modern, intensive farming methods on natural ecosystems and human health back in the 1960s, are nowadays framed within a wider understanding of sustainability and thus have continuously expanded to aspects such as the use of non-renewable and renewable natural resources, the impacts on atmosphere and climate, soil fertility and land and water management, biodiversity, pesticides use, animal welfare, waste disposal, economic practices and environmental policies (Oosterveer and Sonnenfeld, 2011). Although increasing availability of information on food trends, ecological costs of food, etc. may positively impact individual habits and more sustainable consumption, science-based sustainability arguments for eating less meat seem to have not reached the consumers yet, as people may avoid taking personal and moral responsibility for sustainable consumption by using psychological defenses leading to beliefs that meat is natural, normal, necessary, and nice (de Boer et al., 2017; Corallo et al., 2019; Zahra et al., 2022).

On the other hand, eating habits and behavior are shaped by the social and cultural contexts in which people grow up and live (Murcott, 1995). Throughout a person's life, course, specific—consciously or subconsciously taken—food choices may vary according to the social network, social norms, and expectations (Feunekes et al., 1998; Wethington, 2005; Zahra et al., 2022). Additionally, food choices and eating habits may even be influenced by phenomena such as eating disorders like anorexia or bulimia nervosa, obesity, or “fads” and “trends” in dietary choices (Rozin, 2006; Khawandanah and Tewfik, 2016). While obesity, which has turned into a public health threat, and anorexia pose relevant topics above all in developed Western Countries, food shortage remains an unsolved issue in many other parts of the world including for instance the African and parts of the Asian continent. On a macro scale, regulatory authorities, farmer organizations, powerful processing industries, and in particular food retail companies pose decisive actors who shape food choices and eating practices (Spaargaren et al., 2012). Considering globalization as a key principle of modern society, power in the food sector has increased for the retail sectors and has decreased for farmers and farmer organizations (Spaargaren et al., 2012). To sum up, several interrelating factors, including informational cues or social influence on the individual level, which may facilitate but also hinder sustainable behavior, come into play when food choices are being made.

For the study at hand, we focus on what role sustainability plays on an individual level in terms of moralizing food choices and eating behavior and on how much sustainability as a normative principle influences individual decision-making processes and behavior. According to pertinent literature in the field of moral psychology, moral emotions, moral cognition, and moral identity are crucial to the moralization process. Regarding moral cognitions, early psychological research related beliefs about what is morally appropriate and inappropriate mainly to reasoning and reflection processes on whether an act causes harm to other's welfare or infringes individual rights (Piaget, 1965; Kohlberg, 1969; Turiel, 1983; Shweder et al., 1997). However, more recent research revealed that the focus on harm and individual rights, which is rather popular for American and Western systems, is too narrow-minded and that concerns with loyalty, authority, and purity, which could be even equally relevant in other cultures such as Hindu India, also serve as fundamental principles and as bases of moral cognition (Graham et al., 2009, 2011; Haidt, 2013). Moral identity, which refers to the importance of morality to a person's identity, is represented by a combination of one's moral principles, concerns, and goals that—when integrated together—form a key basis of one's self-concept (Blasi, 1983; Colby and Damon, 1993). Hence, moral identity connects moral reasoning and moral values to moral behavior in terms of the more strongly individuals identify as moral, the more they are likely to behave morally (Rozin et al., 1999; Aquino and Reed, 2002; Aquino et al., 2009; Hertz and Krettenauer, 2016). Therefore, people will experience significant dissonance that motivates a realignment between behavior and identity if they fail to engage in behaviors that are consistent with their moral self-concept or if they engage in behaviors that contradict their moral identity (Alicke et al., 1995; Stets and Carter, 2011; Barkan et al., 2015). Finally, pertinent literature from the field of moral psychology highlights the importance of the link between emotions and morality, or more precisely between moral emotions, moral values, and the experience of morality (Damasio, 1994; Rozin et al., 1999; Haidt, 2003, 2012; Mullen and Skitka, 2006). When individuals engage in morally questionable thoughts or behaviors that trigger a moral emotional response including negative emotions such as anger, disgust, shame, or guilt, they are more likely to make negative moral judgments about themselves, which compels them to adjust their thoughts or adapt their behavior, so they live up to their own moral standards (Rozin et al., 1999; Wheatley and Haidt, 2005; Horberg et al., 2009; Wisneski and Skitka, 2017).

With respect to moralization, we furthermore refer to the process of converting individual preferences into values, which for example may involve cognitive routes such as reading through a product label or may be related to strong affective experiences such as seeing pictures of animal cruelty (Rozin et al., 1997). With respect to our research, an example could be the conversion of meat consumption from a personal preference into an immoral activity. The public debate could establish a case that meat consumption and production is harmful to the environment and to animal welfare (Oosterveer and Sonnenfeld, 2011), a clearly immoral act. As a consequence of moral aspects, governments may force corporations to implement the Sustainable Development Goals (SDGs) (United Nations, 2015), which in turn could entitle individuals, who feel more disgusted by the smell of meat and annoyed when looking at meat, to censure meat-eaters.

In this process, it is necessary to consider the differentiation between attitudes, preferences, and beliefs in social psychology (Skitka et al., 2021). Psychological research defines beliefs as representations of the cognitive dimensions, or more precisely as description and perception of a stimulus in one's environment (e.g., an object), its characteristics, and its relationship with other stimuli, that an individual holds and trusts to be true with a certain level of confidence, where the strengths of these thoughts, which may vary across individuals, may influence values and attitudes toward the stimulus and resulting behavior (Katz, 1960; Fishbein and Raven, 1962). Values, which usually do not operate in isolation but rather are part of an integrated value system that is composed of a cluster of similar values, and which similarly to beliefs relate to cognitive processes and allow the prediction of behaviors, are defined as enduring beliefs that a specific mode of conduct or end-state of existence is personally or socially preferable to an opposite or converse mode of conduct or end-state of existence (Rokeach, 1973). Furthermore, values are categorized either as terminal values, which are based on desired states and objectives achieved (e.g., financial security or inner harmony) that an individual strives for or as instrumental values, which reflect modes of behavior (e.g., honesty or responsibility) that enable an individual to achieve terminal values (Rokeach, 1973). Differences between values and preferences include that values are subject to institutional and legal support, which does not apply to preferences, that values are—compared to preferences—much more likely to be transmitted in the social environment, and that values are more durable than preferences, more central to the self, and more internalized (Rozin et al., 1999; Schwartz, 1999). Finally, an attitude toward a stimulus (e.g., an object or a situation), which is defined as an organization of several beliefs around the respective stimulus, differs from a value in terms of having more impact on behavior and in terms of referring to a set of beliefs instead of a single belief (Allport, 1954; Rokeach, 1973). Importantly, attitudes toward a stimulus can cover a range from extremely positive to extremely negative reactions toward that specific stimulus, and they do not necessarily need to be consistent, meaning that positive and negative attitudes might be expressed toward the same stimulus at different times (Wood, 2000).

Thus, a certain behavior like not eating meat can be based on sustainability as a value, which emerged either from an attitude, that has been developed from a certain tradition or convention, or from preferences that have been developed through certain life events and experiences, or from beliefs, described as a moral conviction. Moralization types, on which we will elaborate in more detail in the literature section of this paper, include (1) moral recognition, which includes the recognition and problematization of a personal preference or habit e.g., for meat consumption, (2) moral amplification, which involves validation and strengthening of an existing moral attitude, or (3) demoralization, where people try to avoid moralization because of the disruption and dissonances that might come along with it (Skitka et al., 2021).

Thus, we aim at introducing a theoretical framework for the conceptualization of moralization effects with a specific focus on sustainability communication in general and on certain social practices in particular; here, we focus on food choices, which today have become a “moral morass” (Ankeny, 2016). Discussions about food production and consumption are increasingly loaded with morality, expressed in moral language—not only in mediated “burgeoning debates” (ibid.) and frames like local, made in, free-range, organic, palm oil-free, fair trade, etc. (Honkanen et al., 2006). Sustainability is increasingly part of public discourses (Peterson and Norton, 2007), and the communicative construction of sustainability, including its morality and normative character is debated predominantly from an environmental communication perspective (i.e., Peterson, 1997). Coming from a social constructivist perspective and complementing a communication perspective with a psychological perspective on consumption, food choices, and related communication processes, we add to the existing work and conceptualize sustainable communication as communicatively constructed morality. Moreover, our theoretical framework is inspired by the Sustainability Dissonance Harmonization (SDH) model, which has been developed by Weder et al. (2020). This new model for coping with cognitive and moral dissonance and value incongruences combines Festinger's (1962), Lowell's (2012), and Gardiner's (2013, p. 307) using different aspects of each model to acclimatize it to the notion of sustainability, which is applied to sustainable food choices in the paper at hand. We will relate this idea of demoralization with the concept of moralization or moral amplification, which is well-researched in (social) psychology (related to food and eating behavior Feinberg et al., 2019; Skitka et al., 2021), further represented in the domain theory of attitudes and the psychological program of moral conviction and imperatives, mainly driven by Crimston et al. (2018) and Skitka et al. (2018).

Referring to existing studies on eating behavior being or becoming a moral issue (e.g., as mentioned, Feinberg et al., 2019) and to studies on sustainable consumption and influences on communication (i.e., Golob et al., 2019), we aim to link the theoretical framework on moralization and demoralization effects to empirical data by conducting an exploratory qualitative pilot-study. In this study, we conducted guideline-based interviews with 25 international students to gather information on individual perceptions of food choices and eating behavior, with a specific focus on the role of environmental and sustainability concerns. In our work, we differentiate between values, attitudes, and behavior as well as preferences, conventions, and moral imperatives to learn more about the potential effects of sustainability as the principle on moralization or demoralization. Interview data were analyzed using inductive category formation (Mayring, 2014; Mayring and Fenzl, 2019) to explore sustainability as the principle of moralization or demoralization. From an empirical perspective, we are predominantly interested in moralization effects in sustainability communication in general and in individual social practices, with a focus on food-related decisions and practices. Therefore, this study offers new insights into how to develop a better understanding of changed practices by combining communication with a psychological and behavioral studies perspective. Hence, the results of our work can be valuable to a multi-disciplinary array of scientific researchers, including communication scientists and psychologists, and actors such as companies, institutions, regulatory authorities, and policymakers, who build upon the insights on food choices and eating habits and their connection to sustainability issues to address questions, problems, and solutions around the transition to sustainable food consumption and food production.

With the literature overview at hand, we introduce a concept of sustainable communication as communicatively constructed morality. The background is a social constructivist perspective on communication, which understands individual sense-making as a communication process, either mediated or as interpersonal conversations. Thus, the concept presented in the following offers a new understanding of contradictions and dissonances and therefore of the degree of morality and moral uncertainties in sustainability-related conversations, while complementing existing studies on attitudes and morality as well as sustainable consumption practices and therefore a social-psychology with a communication perspective.

In recent years there has been a growing critical debate about meat consumption due to health risks, environmental concerns, and economic aspects. With respect to the broad spectrum of sustainability concerns related to meat production and consumption (Oosterveer and Sonnenfeld, 2011), which were highlighted briefly in the introduction of this paper, it seems to be an easy task to identify defining moments of moral recognition—and related communication, mainly in the media. Being one of the most energy-intensive and ecologically heavy foods, meat products are said to be highly unsustainable (Dagevos and Voordouw, 2013). On the contrary, the need for sustainable food choices has become more familiar to consumers, going hand in hand with organizations increasingly displaying more information on sustainability as a core value in their products and processes (Wognum et al., 2011). Critical issues like mass meat production, animal cruelty, methane/CO2 problems, climate change, etc. are highly mediatized—from social media to documentaries (Gottwald and Weder, 2021). To identify the degree of morality that influences eating behavior and food choices referring to sustainability as a core value or moral imperative, eating as social practice, related ideologies, and possible moments of change need to be further explored.

The push-pull model that Feinberg et al. (2019) offer for an understanding of (m)eating behavior is used in many consecutive studies; we will not further elaborate on the potential for further descriptive behavioral studies. Instead, from an interdisciplinary, sustainability communication perspective, our empirical work aims to complement the authors' thoughts on the theoretical conceptualization of moralization and demoralization effects in (m)eating behavior by spotlighting specific phenomena in food choices and sustainable eating behaviors. With our qualitative exploratory pilot study, we seek to better understand whether and how sustainability influences eating behavior and food choices, particularly in terms of moralization or demoralization. Hence, a specific focus is on understanding how (much) sustainability as a moral imperative influences individual eating behavior and food-related social practices.

To gather information on individual perceptions of food choices and sustainable eating behaviors, we conducted guideline-based interviews with 25 international students aged between 20 and 40 years from universities in Austria, Australia, and Indonesia. The intention of our sample of international students from different countries, who could join the study for reasons of personal interest regardless of their origin, gender, or eating habits, was to avoid a limitation to the view of western, educated, industrialized, rich, and democratic societies (Henrich et al., 2010). The students were interviewed between April 2020 and August 2020 in face-to-face settings, in telephone interviews, or in online sessions depending on the then-current COVID19-restrictions. Drawing on the study of Leiserowitz et al. (2020), who conducted a nationally representative survey in the US on food choices and eating habits and their connection to climate change, we developed an interview guideline that addressed the following dimensions of individual eating behavior and food-related social practices, with keeping an eye on environmental aspects and morality issues: What are your beliefs and values about food and nutrition? What factors influence an individual's food habits? How did the eating behaviors of people change and which factors make people change their eating behavior? As well, we were interested in the attitudes toward meat consumption and the thoughts with regard to food choices and the environment. We purposely did not specifically ask interviewees about their definition of sustainability or sustainability-related issues in food choices in order to avoid those interviewees simply replicating frames and understandings of sustainability that they heard of, e.g., in the media or in the educational system. Instead, our interviews aimed at focusing on how the interviewees narrate their individual food choices and eating habits, also with a specific focus on environmental aspects, and how much they would address sustainability-related issues and morality issues by themselves.

The recordings of the interviews were literally transcribed (Mayring and Fenzl, 2019) and analyzed using qualitative content analysis (Mayring, 2014; Mayring and Fenzl, 2019) to explore sustainability as a principle of moralization or demoralization. Based on the data at hand, the content analytical technique of inductive category formation is appropriate to answer the questions of analysis on (1) beliefs and values about food and nutrition, (2) factors influencing individuals' food habits and their change, (3) attitudes toward meat consumption, (4) the role of environmental aspects in food choices as well as (5) the role of morality in the context of eating behavior and meat consumption. In the procedure of inductive category formation, we developed categories inductively based on the textual material along with a selection criterion, which we determined on theoretical grounds. In accordance with the required content analytical rules for inductive category formation, we also specified a level of abstraction, on which we phrased the categories (Mayring, 2014; Mayring and Fenzl, 2019). Furthermore, we defined the coding unit, which is the smallest component of the material that can be coded (sensibility), as a clear meaning component (seme) in the text. As a context unit, which serves as the background for the coding decision, we specified the respective interview. By definition, the recording unit is linked to the entire textual material, in this case, all interviews, for inductive category formation (Mayring, 2014). After we specified all these content analytical rules, we performed the text analysis in the online tool www.QCAmap.org (Mayring and Fenzl, 2014; Fenzl and Mayring, 2017), where we counted multiple coding categories within a document. Thus, we received a category system with the inductively developed categories and their corresponding frequencies for each of the above-mentioned questions of analysis as a result. Importantly, the frequencies of each category do not reflect some kind of ranking of what was important to each interviewee. Instead, they should be understood as an indicator of the weighting across all cases.

Participants in this study provided rich data on eating habits, influences, and reasons for changes in food choices. Furthermore, information on the role of morality in the context of eating behavior and meat consumption, in particular, could be analyzed; thus, we were able to identify moralization and demoralization processes, mainly harmonization strategies, related to the concept presented in the theoretical part of the paper. The following sections report the category systems, including exemplifications of the formulated inductive categories based on the statements of the interviewees, as the key findings on the different topics addressed in the interviews.

To sum up, our exploratory qualitative pilot study allows the assumption that there is a multitude of beliefs and influences on individual food choices, ranging from informational cues and social factors to health concerns and sustainability-related issues. In line with previous findings, our results from the participant group studied confirmed that food choices and changes in meat consumption involve a multi-faceted and complex decision-making process, which among others may be heavily influenced by inherent social norms within a person's social network, including family, friends as well as important other peers (Corallo et al., 2019; Zahra et al., 2022). Additionally, the results from our pilot study suggest that food choices and decisions are situational and thus, in some cases, may drastically change over time when circumstances, e.g., new information or social surroundings, call for an adjustment.

However, aspects of moralization and the topic of sustainability played a rather minor role in the decision-making process of food choices among the studied group of international students aged between 20 and 40 years. Similarly, a systematic review of 76 qualitative, quantitative, or mixed methods studies on consumers' perceptions of food-related sustainability, which were conducted between January 2010 and June 2020, revealed that consumers currently believe that sustainability does not (yet) influence their food choices (van Bussel et al., 2022). Thus, the results of the pilot study make us hypothesize that food in general and meat consumption, in particular, are less “morally overloaded” than expected, and sustainability is not a moral imperative related to specific eating behavior. This assumption, which of course needs further elaboration, is supported by previous research, which argues that despite the increasing availability of information on food trends, ecological costs of food, etc. consumers may avoid taking responsibility for sustainable consumption by using psychological defenses (de Boer et al., 2017; Corallo et al., 2019; Zahra et al., 2022). Moreover, we may assume that morality could be a matter of degree rather than a matter of kind (Skitka et al., 2021), and thus, apparently influences the emotional involvement in food choices and eating as social practice. Based on the data collected from the small sample of international students and the interpretations offered, we hypothesize that sustainability apparently works rather demoralizing than moralizing. This suggestion seems rather surprising when facing the literature on sustainable consumption, which talks about sustainability as “adding” morality to individual decision-making (e.g., via labels). What stood out in the empirical data was the recurring justification for personal meat consumption by emphasizing its nutritive value, even after explaining morally reprehensible reasons for meat consumption in general. Thus, we may hypothesize that people, who think that they need to eat meat frequently in order to be and stay healthy and to grow and develop, will not consider going meatless as a feasible solution to ecological problems. This insight from our pilot study calls for additional research, as this “necessity” rationale could serve as the “harmonizing” excuse people cling to in order to avoid dietary change, despite the evidence provided by hundreds of millions of people who thrive on a meatless diet.

The findings of the pilot study at hand allow the assumption that sustainability apparently comes along with less morality and does not work as a moral imperative for the participant group studied. Hence, the research knowledge of this study is particularly interesting, because it allows a deeper understanding of influences and beliefs on individual food habits and its potential for behavior adjustments to changing environmental demands and improving sustainability. Firstly, in our sample of international students, we find that sustainability apparently plays a minor role in food choices. In fact, only some of the participants in our study were able to address the environmental impact of their food choices, which affirms the findings of the systematic review conducted by van Bussel et al. (2022). Furthermore, even if climate change is perceived as a threat, thinking about the horrors of industrial livestock farming, animal rights, pollution, and waste does not necessarily directly influence people to change from a meat- to a plant-based diet. Secondly, individual food choices and changes from meat consumption to veganism or becoming vegetarian are mainly influenced by being exposed to new ideas and stimulations within the closer network of family and friends, rather than via the media, or key events like documentaries on animal cruelty, etc. Family and friends continuously play an important role in eating decisions and—even throughout different life stages—also seem to serve as an important source of information. Furthermore, accessibility as well as general cooking and eating practices (food is celebration vs. food is necessary for survival) influence meat- or plant-based food choices. However, the first insight into different cultural settings and situations, the moral significance of specific eating behavior or food choices apparently varies over time, cultures, and individuals, which leads to and definitely requires further research potential—from many perspectives, including a behavior-oriented, social psychology perspective, a philosophical and also a communication and media perspective to learn where the degree of morality is possibly negotiated.

Research investigating the influence of sustainability overall, and as a moral imperative in particular, on individual food choices and eating behavior can and should be extended with a specific focus on different sampling strategies, which should among others lead to purposive (heterogenous) samples of vegan and meat-eating participants, with a variety of socio-demographic characteristics. It would be interesting to explore, how these aspects contribute to the development of sustainable eating behavior, which is one of the many challenges for modern society. Moving forward, it will also be critical to utilize carefully designed approaches to confront subjects with different types of morality frames and generate a deeper understanding of their influence to engage in sustainable behavior. Above all, the possibility of finding direct insights into the connections between moral influences can only be mapped via a diversion toward attitudes, preferences, and actual behavior.

Most of the sustainability (communication) literature assumes that for sustainable development and a realization of the 17 sustainable development goals (United Nations, 2015) there is the need for change in human values, attitudes, and behaviors in order to achieve a sustainability transition that will meet human needs (Leiserowitz and Fernandez, 2008). Apparently, it is not really, or at least not always, about the kind of attitudes and morality, but much more about their interconnection and probable dissonance in reasoning. Initially, we assumed that sustainability as a moral imperative moralizes and, therefore, stimulates and possibly manifests a certain eating behavior (e.g., a decision and even conviction to not eat meat/fish), by converting, e.g., a plant-based diet from being a preference to being a value. However, we found in the participant group studied, that this is not (yet) the case. Still, people's interpretations of sustainability are strongly related to traditions and conventions, with related practices not necessarily being labeled as “sustainable” (e.g., buying and eating lots of local and seasonal vegetables); “sustainable” eating habits are a preference or choice and possibly related to new or “trendy” routines (inspired by friends or new flat mates), but only very rarely a moral imperative. Instead of moral recognition or moralization, we rather discovered demoralization of food choice and eating behavior, which supports the insights from Skitka et al. (2021), predominantly in terms of demoralization as emotional de-escalation and harmonization strategy, here mostly expressed as behavioral justification instead of belief adjustment (Weder et al., 2020).

The main challenges about sustainability apparently are, firstly, that sustainability as a “blurry” master frame will never be “authority independent,” as Skitka et al. (2021) describe moral imperatives. The main reason for that is that sustainable development is largely institutionalized and part of corporate communication and political strategies (Diehl et al., 2017; Rasche et al., 2017; Weder et al., 2021). Simultaneously, consumers lack key knowledge on some food-related sustainability issues and have difficulties in defining the concept of “sustainability” as well as in estimating the environmental impact of their food choices (Weder et al., 2021; van Bussel et al., 2022). Secondly, sustainability does not really tie in with emotions—or vice versa: sustainability is too abstract and blurry to be happening and influencing on an affectual level. There is a lack of associations and emotive elements where sustainability can be of any moral influence.

While more research is needed to better understand existing and missing social representations of sustainability that influence social practices, our research also reveals that there is a lack of more specific appeals based on sustainability as a social norm and principle. This could then be a promising approach to fostering sustainable food choices and their related eating behavior, as the compliance of most people with social norms has been shown to be conditional upon the compliance of others (Fischbacher et al., 2001; Fehr and Gächter, 2002; Fehr et al., 2002). Hence one challenge is to make norms of desired behavior more salient and tangible, for example, by reducing complexity and providing information on desirable eating behavior from a sustainability perspective, or on how other people take environmentally beneficial food choices in certain situations. Another challenge, which is related to the finding that social norms are a strong influential factor in a person's diet, will be to firstly identify early adopters and influencers within a social group, who are easily influenced in their dieting behavior by other non-social-norm variables such as persuasive moral messages or new health studies. Secondly, with such early adopters and influencers identified, the focus needs to be laid on understanding the collective dynamics with which new ideas, beliefs, and behavior are being spread in social networks and the trajectory they have within this system or population (i.e., Christakis and Fowler, 2007; Watts and Dodds, 2007; Brudermann and Fenzl, 2010).

When discussing the relevance of and influence on food choice, the role of sustainability communication comes into play. Promoting an understanding for the members of the public and establishing the connection between personal behavior and its effect on climate change need to be taken into consideration by regulatory authorities, policymakers, and communicators when designing climate communication. It is important to address consumers' informational needs to enable informed decisions. Furthermore, strategies on how to develop effective communication regarding “motivated reasoning”—only focusing on information that confirms existing beliefs—or misinformation could be encouraged by our study.

The findings of the present study are liable to potential limitations. There was a certain selection bias within our sample as only international students were included, who were interested in participating. Thus, the sample characteristics did not consider specific diets, origin, or gender of the participants, social backgrounds, and professional backgrounds. These are aspects that should be considered in further studies. Even though generalizing from the present sample to other populations regarding the prevalence of various environmental beliefs would be inappropriate, this research was primarily intended to provide initial empirical insights into the implications of beliefs non-experts hold regarding food choices and the influence of sustainability issues such as climate change have on individual decision-making. Nonetheless, the findings are very fruitful for the theoretical conceptualization of moralization and demoralization effects, and very insightful in terms of considering sustainability not to be a moral imperative but rather a harmonization strategy; both aspects need to be picked up from a communication perspective as well as behavior and social-psychological perspective.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving human participants were reviewed and approved by University of Lübeck, Ethics Board. The patients/participants provided their written informed consent to participate in this study.

TF, SL, DV, and FW contributed to the conception of the study. FW developed the theoretical framework of the study. SL, DV, and TF designed the methodology of the study. Data curation, analysis, and investigation were performed by SL and TF. Preparation of the original draft was carried out by FW (theoretical background and framework), TF (methodology), SL (findings), and all authors (discussion and implications). All authors contributed to the manuscript revisions, all major contributions to the revisions were provided by TF. All authors read and approved the submitted and re-submitted versions.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.