4.1 Themes from included studies
Following the full text screening process 297 papers met the criteria for inclusion. Almost all papers focused on consumption of sustainable diets in western economies including Europe, the USA, Canada, Australia and New Zealand. Fifteen papers examined non-western nations including three each from Brazil, India and China, two from the Middle East and one each from Nepal, Peru, North Africa and Vietnam. There were nine main themes identified from the included studies focusing on consumption of sustainable diets. These themes were: diet modelling, consumer behaviour/attitudes, reducing meat consumption, health, policy, dietary guidelines, taxes/carbon pricing, food waste and public procurement (see Figure 2).
Just under half (N = 128, 47%) of all included papers were diet modelling studies which examined the environmental impacts of different dietary patterns and/or food choices. This included analysis of the way in which different diets impact a range of environmental variables such as greenhouse gas emissions, energy consumption, water use, land change use, and loss of biodiversity. Sixty-two papers focused on consumer behaviour/attitudes. These papers covered a variety of areas relating to consumers such as their attitudes towards and knowledge of what constitutes a sustainable diet (e.g. Annunziata & Scarpato, 2014; Barone et al., 2018; Benedetti et al., 2018; Campbell-Arvai, 2015; Clonan & Holdsworth, 2012; Curry et al., 2015; Dixon & Isaacs, 2013), marketing approaches to shift consumers to adopt more sustainable diets, and methods for raising consumer awareness of sustainable diets.
Thirty-four papers specifically explored reducing meat consumption as the primary issue needing to be addressed around sustainable diets. A range of ideas and analysis were covered such as in-depth examination of the environmental impacts of meat consumption and the need for reduction in consumption to mitigate greenhouse gas emissions (e.g. Hedenus et al., 2014; McAlpine et al., 2009; McMichael et al., 2007b; Ripple et al., 2014; Singh et al., 2013; Weis, 2015) and ideas on how to achieve a reduction in meat consumption. A small subset of papers focused on different stakeholder views and actions around meat consumption such as three related papers by Laestadius et al. (2013, 2014a, 2014b) which examined the role of Non-Government Organisations in promoting reduced meat consumption to tackle climate change and one paper by Lerner et al., (2013) which investigated the views of a range of stakeholders in Sweden on their views on meat reduction for sustainability reasons including government agencies, meat producers, politicians and non-government organisations.
Twenty-three papers had a health focus. These either linked the consumption of sustainable diets to better health outcomes or focused on evidence showing that healthier diets are also more environmentally sustainable. Some focused on specific health issues such as obesity or other chronic diseases, while others examined ways to promote healthier and thus more sustainable diets. Nineteen papers had a main theme of sustainable diet policy and focused on evaluating policy options, analysing current policies, or providing an account of recent policy developments. Sixteen papers discussed sustainable diets and their integration into national dietary guidelines. Fifteen papers focused on the implementation of taxes/carbon pricing (including labelling) as a means to increase consumption of sustainable diets, three papers examined food waste as an issue in sustainable diets, and one paper discussed public procurement as a way to increase sustainable diet consumption.
4.2 Application of theories of the policy process
This review did not identify any papers which specifically applied one of the identified political science theories from Table 1. However, there were a number of papers which included discussion of policy in terms of making recommendations, analysing or evaluating policies and discussing influences on the policy process which contained elements of the some of the ideas and concepts from these political science theories. We discuss these in the section below.
1. Includes Policy Recommendations Only
Of the 296 papers that met the inclusion criteria 85% (N=252) included some form of policy recommendations or suggestions. In the vast majority of these papers (N=195) policy recommendations were made without any analysis or empirical evidence on the political and policy context within which the recommendations would need to occur and contained no discussion of the processes by which these policies might come to be adopted or implemented by governments. The most common policy recommendations in diet modelling studies were:
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The need for consumer education and/or information campaigns on sustainable diets (e.g. Carlsson-Kanyama & González, 2009; Ulaszewska et al., 2017).
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Implementing taxation (e.g. Saxe et al., 2012; Scarborough et al., 2014).
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Labelling of foods with greater environmental impacts (e.g. Annunziata, Agovino, et al., 2019; Wilson et al., 2013).
Recommendations in papers focused on consumer attitudes/behaviour also largely focused on governments providing greater consumer education and environmental labelling of food products. Two papers suggested changes to dietary guidelines and two suggested government support for local food networks. Similarly, papers focused on reducing meat consumption mostly recommended increased consumer education and information provision from governments, although again without any discussion of how this might occur taking into account political and socio-cultural contexts. Two papers recommended taxing carbon intensive meat products, and one paper explicitly stated that governments need to stop promoting the consumption of meat.
Recommendations in papers with a health theme were broader, with five papers identifying the need for inter-sectoral and cross-disciplinary action to act on sustainable diets (Finley et al., 2017; Friel et al., 2009; Kevany et al., 2018; Macdiarmid, 2013; Sulda et al., 2010) and two papers mentioning the need for governments to focus on the link between climate change and health (Hallström et al., 2017; Tilman & Clark, 2014). Others also suggested education and information (Lowe, 2014; Michaelowa & Dransfeld, 2008; Quam et al., 2017), emphasising culturally appropriate food (Cavaliere et al., 2018), taxing unhealthy and unsustainable food (Briggs et al., 2013; Lowe, 2014; Michaelowa & Dransfeld, 2008; Quam et al., 2017) and including sustainability in dietary guidelines (Friel et al., 2014). Unsurprisingly most papers that focused on dietary guidelines recommended that environmental sustainability be included in national dietary guidelines, and that populations receive information and education on how to eat sustainably according to dietary guidelines (e.g. (Batlle-Bayer et al., 2019; Irz et al., 2019; Oshiro et al., 2018). Papers on taxes/carbon pricing/labelling and food waste inevitably recommended that initiatives to address these factors be implemented by governments (e.g.(Annunziata, Mariani, et al., 2019; Bonnet et al., 2018; Springmann et al., 2017; Walia & Sanders, 2019). Papers focusing on policy are discussed in the sections below.
2. Includes policy recommendations and evaluates or analyses policies but does not discuss influences on the policy process
Eighteen papers were classified as policy evaluation or analysis papers (See Appendix 1) with five having a theme of reducing meat consumption, one a theme of consumer behaviour attitudes, one a theme of public procurement and the remaining papers having a general policy theme. Policy evaluation and analysis papers tend to focus on the why and what of sustainable diet policy but not the how. Papers may discuss the positives and negatives of different policy options, describe how current or past policy has been approached, or make recommendations for the types of policies required. Papers in this section provide excellent evaluation on policy options against established criteria but lack a focus on the policy process within a given political and socio-cultural context. This is not a criticism of these papers per se, but a commentary on where particular gaps are in the research literature.
Papers that developed frameworks in this review included Downs et al (2017) who developed a policy analysis framework for sustainable diets and applied it to national policies in Nepal, and Friel et al. (2014) who developed a framework to support cross-sectoral health/food policy discussions in Australia with an emphasis on dietary guidelines. Other papers focused on reviewing current and past sustainable diet policies in different contexts, including in the European Union. Lafranconi and Birt, (2017), Lang and Barling, (2013) and Martin and Danielsson, (2016) reviewed the sustainable diet policy terrain in the European Union by summarising policy developments and highlighting difficulties in policy integration (Lang & Barling, 2013) and analysing costs and benefits and effectiveness of policies (Lafranconi & Birt, 2017; Martin & Danielsson, 2016). Other authors took a more global perspective such as Garnett (2011) who discussed proposed policy approaches to mitigate greenhouse gas emissions in the food chain, and Lang and Mason (2017) who outlined national sustainable diet policy in various countries including Brazil, Australia, France and Qatar. Almost all of these policy evaluation papers made recommendations based on their review or evaluation of policies against specific criteria such as Lafranconi and Birt (2017) who stated that policies for sustainable healthy nutrition “should be supported by overarching legislation, an institutional infrastructure, educational structures that include appropriate capacity building” (p. 30) while Reisch et al. (2013) identified “A first priority…is to develop integrative, cross-sectoral, population-wide policies” (p.15). These types of broad recommendations require research into why they have not happened to date, and what might be barriers or enablers of policy change. Applying theories of the policy process to sustainable diet policy would address gap.
Thus while there are some thorough and well-developed criteria against which to judge sustainable diet policies which have been applied, they lack analytic depth on the process by which a policy could change. There could be greater focus on judging policy options against their fit within a political and socio-cultural context in addition to judging against a set of predefined evidenced based criteria. Having some understanding and knowledge of the social and political context is a prerequisite for understanding the utility of policy options which is something that is currently not the focus of these evaluation pieces.
The common approach in the research literature on policy evaluation papers is to develop frameworks that could be applied by governments to develop policies or used to evaluate the effectiveness of current policies, but they do not focus on the policy change processes that would need to occur in particular political and socio-cultural contexts to enable policy action. An understanding the processes by which policy could grain traction within a particular political and socio-cultural context provides guidance for the content of policy recommendations and frameworks which could be factored into these evaluation frameworks and pieces.
3. Includes policy recommendations and discusses influences on the policy process but does not apply a theory of the policy process
Of all the papers reviewed there were only 17 that included discussion of one or more influences on the policy process which had ideas and concepts seen in the political science theories reviewed in the Introduction (See Appendix 2).
Policy process influences identified were:
i. Coalitions/networks (Beverland, 2014; de Bakker & Dagevos, 2012; Denniss et al., 2021; S. James, 2015; Jelsøe, 2015; Johnston et al., 2014; Joyce et al., 2014; Laestadius et al., 2014a; Lawrence et al., 2015; Rose et al., 2021; Santaoja & Jauho, 2020)
ii. Organisational, institutional and political system factors (Beverland, 2014; de Bakker & Dagevos, 2012; Denniss et al., 2021; S. James, 2015; Johnston et al., 2014; Lawrence et al., 2015; Rose et al., 2021; Santaoja & Jauho, 2020; Sedlacko, Pisano, et al., 2013)
iii. Narratives/Framing (Beverland, 2014; S. James, 2015; Jelsøe, 2015; Laestadius et al., 2013; Rose et al., 2021; Sedlacko, Pisano, et al., 2013)
iv. Dominant political ideology (Beverland, 2014; Denniss et al., 2021; Jelsøe, 2015; Rose et al., 2021)
v. Use of evidence (Dagevos & Voordouw, 2013; S. James, 2015; Jelsøe, 2015; Johnston et al., 2014; Laestadius et al., 2014a; Lawrence et al., 2015; Rose et al., 2021; Simmonds & Vallgårda, 2021)
vi. Personal values, beliefs, and socio-cultural norms (Beverland, 2014; Dagevos & Voordouw, 2013; de Bakker & Dagevos, 2012; Jelsøe, 2015; Laestadius et al., 2014a, 2014b; Santaoja & Jauho, 2020; Seed, 2015)
However, although the papers in this section identified some of these elements no papers specifically mentioned any policy process theories by name. Below we discuss the policy process influences identified in the 17 papers.
i. Influence of Coalitions/Networks
Eleven of the seventeen papers mentioned the influence of coalitions or networks on sustainable diet policy. The way in which coalitions or networks of policy actors are integral parts of the policy process is highlighted in theories of the policy process such as Kingdon’s Multiple Streams Analysis (Kingdon, 1995) which discusses the importance of policy entrepreneurs in influencing policy change and the Advocacy Coalition Framework which organises policy actors into advocacy coalitions based on shared beliefs and co-ordination strategies (Jenkins-Smith et al., 2014).. While these papers mentioned the importance of coalitions these were not analysed in depth in regard to the strength or otherwise of these networks.
Eight papers mentioned power imbalances between sustainable diet policy actors (Beverland, 2014; de Bakker & Dagevos, 2012; Denniss et al., 2021; S. James, 2015; Jelsøe, 2015; Rose et al., 2021; Santaoja & Jauho, 2020; Seed, 2015) and identified the food industry and/or farming lobby groups as having greater political access and influence, which was concluded to be a significant reason for limited political action on sustainable diets. However, again these eight papers did not conduct extensive analysis of power imbalances, rather they focused on the “what” is happening rather than the “how” and “why”. Johnston et al. (Johnston et al., 2014), Joyce et. al (Joyce et al., 2014) and Lawrence et. al. (Lawrence et al., 2015) mentioned the need to understand policy networks and the way different policy actors influence political agendas with Johnston et al. (Johnston et al., 2014) stating that to overcome political challenges to governance of sustainable diets will require “co-operation, coordination, and negotiation across all stakeholder groups” (p. 426). However without empirical evidence on the values and beliefs of different stakeholders or the ways in which policy actors form coalitions and networks and exert political influence in particular political contexts it is difficult to draw any firm conclusions on their importance as barriers or enablers of policy change.
Two papers by James et al. (2015) and Denniss et al. (2021) attempted to address this gap by using empirical evidence from food policy actors in Australia to help understand the barriers and enablers of policy action on consumer adoption of healthy and sustainable food behaviours. James et al. (2015) conducted semi-structured interviews with food policy stakeholders including the food industry, government, and non-government organisations while Denniss et al. (2021) conducted a Delphi study with similar stakeholders. Based on the barriers and enablers identified in the interviews James et al. (2015)developed a framework for intersectoral action and Denniss et al. (2021) made a number of similar policy recommendations including the need to build relationships with key stakeholders and developing greater understanding of the policy process. These were one of the few examples that provided a bit more analytic depth on the policy process albeit that a specific political science theory was not used in the analysis. This section of the paper has highlighted how there is a considerable gap in application of political science theories on coalitions and networks in relation to sustainable food policy. This hampers action in this area as practitioners and policy makers have little research by which to guide their actions and strategies.
ii. Organisational, institutional and political systems
The study of institutions, organisations and political systems within the policy process has been the focus of much work in political and social sciences (Mahoney & Thelan, 2010) for example the Institutional Analysis and Development Framework is a theory of the policy process which provides a way to think about how different institutions cultivate collective action (Cairney, 2019). Six papers mentioned either organisational factors, institutions or political systems as impacting sustainable diet policy. From interviews with stakeholders involved in Australian sustainable diet policy James (2015) identified that organisations give little attention to sustainable diets as many don’t see it as “core business” largely because of a lack of institutional or political interest or prioritising of sustainable food supply and demand issues. Similarly, in investigating factors influencing NGOs to campaign on reduced meat consumption Laestadius et al (2014) found that depending on their focus (environment, food, health) some NGOs had a low level of engagement with the issue as it was not seen as their primary focus. However, no policy theories were specifically mentioned as having guided the analyse of their empirical data.
Institutions and political systems were discussed by Santaoja and Jauho (2020) in the context of the Finnish Dietary Guidelines. They identified a situation of institutional ambiguity in regards to where and who is making sustainable food policy with no political consensus on what sustainable diets. It was noted that policy makers had little independence in the contexts in which they worked and were thus reluctant to experiment with policy on sustainable diets. Rather than using any policy theories the authors employed the concept of ontonorms to help understand the integration of sustainability into dietary guidelines.
iii. Narratives/Framing
Many policy theories discuss the links between evidence, persuasion, and the framing of policy problems (which sit within a broader environment where particular beliefs may dominant discussions) ( Cairney et al., 2016). One theory of the policy process – the Narrative Policy Framework, explicitly focuses on the importance of narratives in creating policy change (McBeth et al., 2014). The way sustainable diet policy has been framed was mentioned in five papers (Beverland, 2014; S. James, 2015; Jelsøe, 2015; Johnston et al., 2014; Laestadius et al., 2013). For example Beverland (2014) commented that marketers, promoters and critics have often framed vegetarian or “ethical” diets as something for those who are culturally privileged rather than for the mainstream and language around reducing meat consumption is framed in anthropogenic terms which conceals how meat consumption impacts sustainability. Additionally he identified an economic logic as being pervasive in sustainability narratives. Similarly, James (2015) showed how in the Australian context economic themes and frames are often used by industry stakeholders when they define sustainability and stakeholders describe concepts of health and sustainability separately with health receiving the greatest emphasis. In discussing dietary guidelines Jelsøe (2015) argued that dietary guidelines act to reproduce and strengthen the discourse around food and health where health issues are seen as isolated from other considerations such as sustainability. However although some narrative and framing issues were identified as possible barriers to policy action on sustainable diets no papers utilised any narrative or framing policy theories to attempt to further analyse narratives around sustainable diet policy. Again this is another potential limitation whereby the use of a theory to guide the analysis may reveal possible strategies and actions to promote sustainable dietary policies
iv. Dominant political ideology
A number of papers made mention of dominant economic or neoliberal political ideology acting as a barrier to sustainable diet policy. This often has interactions with other influences on the policy process. For example in their examination of how livestock industry practices influence sustainable diet policy in the US Rose et al. (2021) discussed the way industry framed their practices as of economic importance in order to align with the dominant economic rationalist ideology of government. Denniss et al. (2021) similarly noted that neoliberal ideology and prioritisation of economic interests act to exacerbate a lack of “political will” by governments to act on sustainable diets.
v. Use of Evidence
There is a large literature demonstrating the gap between production of evidence and a policy making response (Cairney et al., 2016; Clavier & de Leeuw, 2013b; VanLandingham & Silloway, 2016) in many policy areas including social, environmental and health policy. However studies in these areas have rarely utilised insights from political science policy theories to explain the evidence-policy gap (Cairney et al., 2016; Clavier & de Leeuw, 2013b). Similarly although six papers in this review touched on the use of evidence in sustainable diet policy none used a policy theory to further analyse evidence use in the policy contexct. Dagevos and Voordouw (2013) pointed out that despite there being abundant scientific evidence on the sustainability problems of meat consumption “political attention is conspicuously absent”. In contrast James (2015) found it was a lack of evidence of what constitutes as sustainable diet that acted as a barrier to inter-sectoral action on sustainable diets. Jelsøe (2015), Johnston et al. (2014) and Lawrence et al. (2015) also commented that their either wasn’t enough evidence on the metrics of sustainable diets in particular contexts or that the evidence was too fragmented or overwhelming for politicians to take meaningful action. Additionally Jelsøe (2015) noted that the food industry has questioned the evidence around sustainable diets as a way to avoid sustainability being included in dietary guidelines. Utilising empirical evidence combined with policy theory to explore these hypotheses would enable a greater understanding of barriers to policy action.
vi. Personal values, beliefs and socio-cultural norms.
Theories of the policy process recognise the importance of the public mood, and the values and beliefs of stakeholders in the way the policy process operates. A number of authors in this review commented on the way meat consumption is associated with socio-cultural norms and beliefs. Beverland (2014) argued that in developed economies consumption becomes more about expressing identity than fulfilling basic needs with consumption of meat being the most obvious example, reflecting identity issues of gender, class, race, and culture, which acts as a barrier to political action on sustainable diets. Similarly Dagevos & Voordouw (2013) commented that it is unlikely consumers would be receptive to policies around reduced meat consumption due to a carnivorous food culture and Jelsøe (2015) noted that providing advice on what people should eat can be perceived as a threat to individual choice. In their exploration of NGO messaging Laestadius et al. (2014a, b) identified a negative feedback loop on messaging to reduce meat consumption – when governments and the public see the issue as unpopular or uninteresting NGO’s reduce their messaging efforts which in turns deprives the issue of the attention it needs.