Scientists’ Views on Sustainable Healthy Diets: A Reflection Process Towards a Multi-Disciplinary Consensus

Abstract

Achieving a Sustainable Healthy Diet (SHD) is one of the goals of public policy programmes to improve human health and the health of the planet. It is a complex objective that requires the participation of all actors in the food system. One group is scientists who are involved in the study of food in a variety of disciplines. This paper aims to analyse the views that Spanish researchers from different disciplines have on the concept of an SHD and the factors that, in their opinion, hinder or facilitate its promotion in Spain. We carried out a Delphi survey structured in three rounds with scientists from Agricultural Sciences, Natural Sciences, Health Sciences, and Social Sciences. The results show that the experts are in agreement that an SHD is based on nutritious food, with low environmental impact, secure, safe, and accessible. They believe that the main obstacle to promoting SHDs comes from the power of the food processing and distribution industry to influence the system and the difficulties governments face in promoting SHDs. They stress that the main areas for action are food education, regulation of the food system, and changing the framework of governance and the relations between actors in the food system. The process of reaching consensus shows important overlaps between disciplines, especially between experts from Social and Human Sciences and Health Sciences, while those in Natural and Exact Sciences tend to be at the opposite extreme to those in Agricultural Sciences.

1. Introduction

There is increasing evidence that intensive agricultural and livestock practices, the processing and transport of food, as well as new patterns of consumption are among the most detrimental activities in terms of their impact on the environment, including climate change. At the same time, this sector is highly vulnerable to the effects of the ecological crisis, as the relationships between agriculture and the environment are varied, complex, and interdependent [1]. There are also significant inequalities in the food system with regard to accessibility, affordability, and food governance [2], both in high-income and low-income countries., the number of people unable to afford a healthy diet was already high. Instead of decreasing, this number has increased substantially since then: first, during the global financial crisis of 2007 and, more recently, due to the effects of the COVID-19 pandemic and the war in Ukraine [3,4]. Also important has been the impact the food system has had in eroding cultural heritage, with loss of varieties, species, management and knowledge associated with agricultural activity and culinary skills [5], and diversity among food cultures [6].

The severity of these interconnected challenges has led public bodies and experts to consider the need to work with a multi-dimensional concept of sustainability to achieve diets that are sustainable, healthy, and equitable [7,8,9]. This transformation is also seen as critical to achieving the United Nations’ Sustainable Development Goals by 2030, as approximately 70 of the 169 goals require food action [10,11]. Establishing a consensus among food-system stakeholders (producers, processors, distributors, restaurateurs, consumers, scientists, politicians, NGOs, etc.) on the system’s sustainability is one of the objectives set by the scientific community and institutions to promote Sustainable Healthy Diets (SHDs).

However, analysts have warned us of the challenges involved in formulating an SHD and putting it into operation because of the multiplicity of actors, ecosystems, and sectors involved [12,13]. One challenge is the different understandings of what a sustainable and healthy diet is among the consumers [14,15], policy actors [10,16], and scientists [17]. Another challenge is the difficulties faced in reaching consensus on the most appropriate measures to promote SHDs in a food system with a lack of connection between the social actors and unequal power relations [18,19,20].

It has also been noted that different disciplines treat sustainability and health in distinct ways when analysing food, emphasising bio-medical aspects, and social, economic, or environmental dimensions [7,21,22], with each field of study applying different models, metrics, and measurements to determine what is sustainable and what is healthy, which significantly complicates the analysis [23]. For example, the field of Health and Nutrition Sciences has traditionally focused on the area of healthy eating, providing data on what foods are most conducive to improving health, how much and how often they should be consumed and, secondarily, how, when, and where they should be consumed [24,25]. This has led to a focus on particular dimensions (biological aspects of health) and specific actors in the food system (health workers and nutritionists, educators and communicators, policy-makers and consumers). This approach has been criticised for focusing exclusively on consumers’ individual responsibility for eating correctly [26,27], for not taking account of how food consumption habits impact the environment [28], and for not integrating the socio-cultural aspects of food, the complexity and multi-dimensionality that characterise the food system, or the new social demands with respect to food [29,30].

Research on the environmental impact of agricultural activity has made great progress [31]. Multiple studies have attempted to measure the environmental impact of food and to quantify the sustainability of food systems. For example, life cycle analysis (LCA) quantifies the land, water, and energy resources mobilised during food production and consumption [32]. Researchers have also drawn up definitions of sustainable food systems through models based on permutations of the ‘three Es’ of ecology, economy, and equity [33]. These approaches have also been challenged, in particular for focusing the debate focused on farmers (actor level) or on agriculture (food chain level) and the environment (impact dimension). They also fail to consider the nutritional dimension and cultural factors that are intrinsic to diets [6,34,35].

The lack of multi-disciplinary perspectives and the absence of a common interpretative framework is impeding the understanding of the complexity of the concept of an SHD and the nexus of health–agriculture–food–environment [36,37,38,39]. This lack of coherence in formulating, measuring, and evaluating SHDs explains the difficulty in popularising them among the public. In fact, the co-existence of different conceptions of what constitutes a Sustainable Healthy Diet, as well as many countries’ resistance to incorporating environmental criteria in their nutritional guidelines, constituted the starting point for the publication in 2019 of the Sustainable Healthy Diets—Guiding Principles [40], which defines SHDs as: ‘dietary patterns that promote all dimensions of individuals’ health and wellbeing; have low environmental pressure and impact; are accessible, affordable, safe and equitable; and are culturally acceptable. The aims of Sustainable Healthy Diets are to achieve optimal growth and development of all individuals and support functioning and physical, mental, and social wellbeing at all life stages for present and future generations; contribute to preventing all forms of malnutrition (i.e., undernutrition, micronutrient deficiency, overweight and obesity); reduce the risk of diet-related NCDs [non-communicable diseases]; and support the preservation of biodiversity and planetary health. Sustainable healthy diets must combine all the dimensions of sustainability to avoid unintended consequences’ [40].

This report was the result of the process of consulting experts, reaching agreement not only on a consensus term ‘Sustainable Healthy Diets’, but also on a holistic and multi-dimensional approach. It seems that this new context is encouraging researchers to tackle food problems with a systemic approach, which involves considering the interactions between actors and focusing on their relationships to find joint solutions [25], and indicating the need to seek consensus among scientists along with creating indicators that integrate the economic, social, and cultural variables of SHDs [9,17,22,41]. Dialogue and interaction between scientists and other stakeholders has also been emphasised as the key element in realising SHDs [13,42,43]. Scientists, as experts, are seen as part of the complex machinery of the food system and a key node in facilitating or impeding governance, which is why it is important to analyse their positions with regard to SHDs in relation to other actors: to government and companies, to public and private managers, to representatives of the food industry, and to consumers [44,45,46].

This paper aims to contribute to the debate by exploring the role of science as an agent with the capacity to shape the formulation of sustainable and healthy diets and to transform the food system that supports them. We explore the views that Spanish researchers from different disciplinary fields have of the concept of Sustainable Healthy Diets, and the factors that, according to these experts, hinder or help progress towards SHDs in Spain. We examine whether their views coincide or diverge, and whether there are discrepancies between the experts from different disciplines that represent an obstacle to the promotion of SHDs.

2. Materials and Methods

2.1. The Delphi Method and Its Application to Sustainable Food Systems

The Delphi method is a structured process based on the results of multiple rounds of consultation sent to a panel of experts. An aggregated summary is provided following each round, which allows the individual experts to adjust their responses according to the results of the group. This leads to a consensus in the group’s thinking, a group opinion or decision that comes from bringing together individual opinions and agreements [47,48,49].

Scholars consider the technique is well suited to analysing the variety of wicked problems and the scientific and political complexities of food systems [45]. In the literature of food studies, researchers have applied the Delphi technique to assess complex topics at the level of the food system, such as generating models of trust-building that can be implemented following food scares [50]; increasing stakeholder input in food-risk governance [51]; identifying food-system vulnerability factors in Europe [42], formulating the characteristics of sustainable food systems [17,45,52]; and determining how policy actors [16,53] and smallholder producers [54] define and contribute to healthy, safe, and sustainable food systems.

In this study, we used a modified Delphi method, structured in three rounds to reach consensus on a range of aspects associated with the promotion of healthy and sustainable food patterns. The modifications were aimed at focusing the experts on the topic of study and collecting a wide range of perspectives, including dissent, which can provide as much insight as consensus does [42].

2.2. Participants on the Delphi Panel

In order to select the experts, we reviewed the most important publications in Spain on sustainable and healthy food. The following search terms in English and Spanish were used: ‘sustainab* AND health* AND (food OR diet* OR food system* OR agr* food system*, OR food consumption, OR food production, OR nutrition*, OR food polic*)’, incorporating the filter ‘Spain’ and the time range ‘2016–2021’. We obtained 500 articles in English and 138 articles in Spanish. Applying exclusion criteria (duplicate articles, articles not focused on Spain, with subject matter far from the topic, or not considering both sustainability and health), we obtained a sample of 150 articles, from which 202 potential researchers were selected to participate in the Delphi panel. They were classified, according to their field of study, into four major disciplinary groups: Natural Sciences (biology, environmental sciences, chemistry, biochemistry, food technology); Health Sciences (nutrition, epidemiology, public health); Agricultural Sciences (agronomy, veterinary science, forestry, urban planning); and Social and Human Sciences (sociology, anthropology, history, psychology, law, and communication).

2.3. Data Collection

Round one took place between June and July 2021. A total of 18 researchers from the four pre-selected disciplinary fields were contacted, of whom ten agreed to be interviewed (

Table 1. Experts participating according to disciplinary grouping in the rounds of the Delphi process.

Disciplinary Areas	Experts Participating in Round 1	Experts Participating in Rounds 2 and 3
Natural Sciences	3	6 (15.78%)
Health Sciences	2	12 (31.57%)
Agricultural Sciences	2	6 (15.78%)
Social Sciences	3	14 (36.84%)
Total	10	38 (100%)

). The in-depth, semi-structured interviews were conducted online and comprised a series of open-ended questions on sustainable and healthy food. Of these questions, three are analysed in this article: What is the concept of an SHD? What are the barriers to promoting it in Spain? What action should be implemented to promote SHDs? In qualitative research, small purposive samples are appropriate to ensure depth of analysis, rather than aiming for statistical representativeness. Round one was conceived as an exploratory phase within the Delphi process, aimed at obtaining in-depth insights to inform the design of the Delphi questionnaire items. The results of these interviews were the basis for further exploration of the themes in rounds two and three of the Delphi panel.

Round two ran from May to June 2022. An email was sent to 155 experts, balanced according to their affiliation with each of the four scientific fields, and 38 experts replied. The email contained a link to an online survey, developed with the free software LimeSurvey 5.6.1. The questionnaire comprised the three following sections: (1) the principles of an SHD and the aspects associated with it; (2) the barriers to promoting it; (3) the action needed to promote SHDs. In each section, the experts were asked to establish a ranking, prioritising the importance given to the different response items [42,55]. In order to allow experts to comment on their answers, each section included a text box to provide further information. During the recruitment process, additional efforts were made to balance the disciplinary distribution of participants. Experts from underrepresented fields, particularly Agricultural Sciences and Natural Sciences, were specifically targeted through repeated invitation rounds. Despite these efforts, participation from these fields remained lower than from others. Nevertheless, the final sample of 38 experts is consistent with methodological standards for Delphi studies and is sufficient to ensure the rigour of the process.

In round three, carried out in December 2022, a report was provided by email to the 38 participating experts, including their individual responses and anonymised group results from round two, giving them the possibility to modify any replies they considered relevant, in the light of the results obtained and the consensus established. Three participants made changes to Section 1 and Section 2.

2.4. Data Analysis

Responses to the open-ended questions in all rounds were coded using the qualitative analysis programme MAXQDA 2022 and analysed with discourse analysis techniques. In the questionnaire’s questions about prioritisation, a weighted score was assigned according to the place each item occupied in the ranking and the frequency with which it was selected. This score was then divided by the total number of participants. A consensus criterion was established as the grouping of values within the 75th percentile (>75) [56] in

Table 2. Results for the different topic areas/blocks. Average score by percentile in each round (N = 38).

Item	DIMENSIONS OF A SUSTAINABLE HEALTHY DIET	Round 2	Round 3
4	Based on nutritious food ensuring an optimal state of health	13.89	14.00
9	Low environmental and climate impact	13.45	13.68
1	Safe and secure	13.13	13.13
15	Available and accessible	10.92	10.92
12	Affordable	10.97	10.87
11	Respect for workers’ rights, health, and safety	10.11	10.32
3	Reduction and optimisation of food waste	9.89	10.08
14	Fair remuneration for food producers	9.71	9.68
2	Balance between actors in the food system	9.42	9.34
13	Reduced presence of pesticides and antibiotics	9.32	9.21
7	Socially appropriate and culturally acceptable	8.74	8.63
10	Low level of processing	8.53	8.55
5	Local or short supply chain	8.26	8.45
6	Based on organic food	7.58	7.42
17	Minimal packaging, reduced presence of plastic in packaging	7.26	7.29
8	Low presence of animal protein	7.03	7.24
16	Participation of different actors in food governance processes	6.39	6.26
18	High animal welfare standards	6.39	6.10
Item	BARRIERS TO THE PROMOTION OF HEALTHY AND SUSTAINABLE FOOD IN SPAIN	Round 2	Round 3
14	Strong influence of the food industry and large-scale distribution on the organisation of production, distribution, purchasing habits, and food policies	15.08	15.11
11	Lack of political ambition to implement effective measures to promote sustainable and healthy diets.	13.42	13.42
6	Poor regulation of unsustainable and unhealthy food, and lack of enforcement measures.	11.89	11.92
13	Sustainable and healthy food is not accessible and affordable for a significant portion of the population.	11.76	11.82
7	Measures to promote sustainable and healthy food centre on individual consumer choices.	11.26	11.29
3	Externalities (positive and negative) are not incorporated into food prices.	10.24	10.32
16	The level of food education of the public is low.	9.68	9.50
2	Information on food and the food system is limited, confusing, and inaccurate.	9.53	9.47
15	Initiatives to promote sustainable and healthy food promoted by citizens and social organisations are co-opted by the dominant system.	9.53	9.39
9	Poor integration of the views, measures, and actors working on food.	8.97	9.03
8	Priority is given to the health dimension in recommendations and measures on food, leaving aside the environmental and social justice dimensions.	8.74	8.84
4	Poor communication and coordination between the scientific disciplines working on sustainable and healthy diets.	8.26	8.29
5	With respect to food, the ‘sustainable’ and ‘healthy’ aspects tend to be treated separately.	8.21	8.24
12	There is insufficient dissemination and transfer of research results on sustainable and healthy food.	8.13	7.79
10	There is no specific body dedicated to promoting sustainable and healthy diets.	7.76	7.79
17	Primacy of urban over rural needs.	6.97	7.00
18	The export-oriented nature of the Spanish agri-food sector and dependence on third countries for imported food.	6.32	6.58
1	The presence of global crises (pandemics, wars, etc.) is slowing down the transition to sustainable and healthy food models.	5.24	5.26
Item	INITIATIVES TO PROMOTE HEALTHY AND SUSTAINABLE FOOD IN SPAIN IN THE FIELD OF TRAINING, EDUCATION, AND SCIENCE	Round 2	Round 3
1	Encourage a change in the system of values regarding food to prioritise people’s health and the health of the planet.	7.29	7.29
2	Promote effective legislation/regulation of food information in labelling and/or advertising.	6.82	6.82
5	Promote cross-cutting food education for all citizens.	6.55	6.55
3	Provide sufficient, verified, and accurate information on food and the food system.	6.50	6.50
4	Promote the coordination and integration of the different scientific disciplines working on sustainable and healthy food.	5.16	5.16
8	Strengthen the socio-cultural and environmental dimensions in food research and recommendations to consumers.	5.11	5.11
7	Enhance the role of nutritionists in schools and introduce nutritionists in public health services.	4.66	4.66
9	Improve accessibility to the results of research on sustainable and healthy food and promote its dissemination among the public.	4.58	4.58
10	Promote knowledge and appreciation of the rural environment and the agri-food system.	4.47	4.47
6	Create a specific logo to distinguish sustainable and healthy food.	3.87	3.87
Item	INITIATIVES TO PROMOTE HEALTHY AND SUSTAINABLE FOOD IN SPAIN BY PROMOTING CHANGES IN THE DIFFERENT DIMENSIONS OF THE FOOD SYSTEM	Round 2	Round 3
1	Establish measures to make sustainable and healthy food accessible and affordable for all citizens.	9.03	9.00
7	Implement measures to encourage the consumption of sustainable and healthy foods.	7.55	7.61
11	Encourage public procurement of sustainable and healthy food in public institutions (hospitals, schools, care homes, prisons, etc.).	6.82	6.79
4	Promote the agroecological transition of production systems.	6.50	6.53
3	Tax unhealthy foods with a high environmental impact.	5.97	6.00
6	Encourage and reappraise local, artisanal and organic food production.	5.74	5.82
10	Promote short food supply chains and local commerce.	5.61	5.58
8	Generate market opportunities so that the different actors in the food system can move towards sustainable and healthy food models.	5.37	5.34
5	Design a territorial model to reduce depopulation and maintain agricultural activity.	4.92	4.87
2	Monitor and follow up existing measures to promote sustainable and healthy food (e.g., PAOS campaigns against food waste, self-regulation of food advertising, etc.).	4.42	4.42
9	Orient agri-food companies’ Corporate Social Responsibility action of towards sustainable and healthy food.	4.08	4.05
Item	INITIATIVES TO PROMOTE HEALTHY AND SUSTAINABLE FOOD IN SPAIN IN THE FIELD OF GOVERNANCE AND THE FRAMEWORK OF RELATIONS BETWEEN ACTORS IN THE FOOD SYSTEM	Round 2	Round 3
1	Promote spaces that foster smooth collaboration and communication between the different actors in the food system.	6.21	6.21
2	Build multi-stakeholder and multi-level governance structures.	5.95	5.95
4	Modify the current structures of government, seeking coordination and integration of responsibilities and jurisdictions, and mainstreaming its activities.	5.79	5.79
9	Promote the creation of local food policies and councils.	5.58	5.58
3	Encourage the scaling up of successful initiatives on sustainable and healthy food.	5.34	5.34
8	Promote interaction between civil society initiatives and networks developing sustainable and healthy food initiatives.	4.82	4.82
5	Give greater powers to the Spanish Agency for Food Safety and Nutrition.	4.58	4.58
7	Create a new Ministry or General Secretariat with the specific task of promoting sustainable and healthy food and with the capacity and authority to work on this issue as a whole.	3.71	3.71
6	Promote private governance mechanisms (standards, certifications, seals, etc.) in the promotion of sustainable and healthy food.	3.03	3.03

. Responses were also analysed according to the experts’ disciplinary groups in order to explore convergences and divergences between different scientific fields, in line with [16,42] (Appendix A,

Table A1. Average score by discipline on the dimensions of sustainable and healthy diets (N = 38).

DIMENSIONS		SCORE BY DISCIPLINE
		Agricultural Sciences	Natural Sciences	Health Sciences	Social Sciences
1	Safe and secure	13.67	14.33	11.50	12.52
2	Balance between the actors in the food system	8.00	9.83	9.00	9.32
3	Reduction and optimisation of food waste	9.67	12.67	9.08	9.84
4	Based on nutritious food ensuring optimal state of health	15.17	17.50	15.83	13.32
5	Local or short-supply chain	8.00	4.83	9.50	9.24
6	Based on organic food	9.33	5.67	5.83	7.04
7	Socially appropriate and culturally acceptable	9.33	3.67	9.50	9.64
8	Low presence of animal protein	3.17	6.50	10.08	8.36
9	Low environmental and climate impact	15.67	13.17	13.17	13.24
10	Low level of processing	7.33	7.83	10.33	9.12
11	Respect for workers’ rights. health. and safety	10.50	11.00	9.50	9.6
12	Affordable	8.17	12.00	10.00	11.24
13	Reduced presence of pesticides and antibiotics	15.17	7.17	7.33	8.16
14	Fair remuneration for food producers	10.67	10.50	8.92	9.04
15	Available and accessible	9.33	12.50	11.83	11.32
16	Participation of different actors in food governance processes	6.17	5.83	6.67	6.44
17	Minimal packaging. reduced presence of plastic in packaging	6.00	9.00	6.25	7.4
18	High animal welfare standards	5.67	7.00	6.67	6.16

,

Table A2. Average score by discipline on the barriers to promoting a sustainable and healthy diet in Spain (N = 38).

BARRIERS		SCORE BY DISCIPLINE
		Agricultural Sciences	Natural Sciences	Health Sciences	Social Sciences
1	The presence of global crises (pandemics, wars, etc.) is slowing down the transition to sustainable and healthy food models.	5.17	4.67	4.58	6.46
2	Information on food and the food system is limited, confusing, and inaccurate.	12.17	9.00	8.58	9.23
3	Externalities (positive and negative) are not incorporated into food prices.	10.17	8.00	9.42	11.69
4	Poor communication and coordination between scientific disciplines working on sustainable and healthy diets.	9.83	8.17	9.92	6.15
5	With respect to food, the ‘sustainable’ and ‘healthy’ aspects tend to be treated separately.	7.17	10.00	7.33	9.00
6	Poor regulation of unsustainable and unhealthy food, and lack of enforcement measures.	10.17	10.00	13.50	11.77
7	Measures to promote sustainable and healthy food centre on individual consumer choices.	8.17	11.50	12.67	11.15
8	Priority is given to the health dimension in recommendations and measures on food, leaving aside the environmental or social justice dimensions.	9.00	7.67	7.92	10.15
9	Poor integration of the views, measures, and actors working on food.	9.83	8.00	10.83	7.85
10	There is no specific body dedicated to promoting sustainable and healthy diets.	6.67	8.50	8.92	7.00
11	Lack of political ambition to implement effective measures to promote sustainable and healthy food.	12.33	13.33	15.33	12.00
12	There is insufficient dissemination and transfer of research results on sustainable and healthy food.	7.33	9.83	6.92	7.85
13	Sustainable and healthy food is not accessible and affordable for a significant portion of the population	11.50	13.17	11.58	11.31
14	Strong influence of the food industry and large-scale distribution on the organisation of production, distribution, purchasing habits, and food policies.	16.33	12.50	16.08	15.00
15	Initiatives to promote sustainable and healthy food promoted by citizens and social organisations are co-opted by the dominant system.	10.00	9.17	9.83	8.62
16	The level of food education of the public is low.	9.33	14.33	6.50	10.00
17	Primacy of urban needs over rural needs	7.83	8.17	5.00	8.23
18	The export-oriented nature of the Spanish agri-food sector and dependence on third countries for imported food.	8.00	5.00	6.08	7.54

,

Table A3. Average score by discipline on initiatives to promote a sustainable and healthy diet in Spain, in the area of training, education, and science. (N = 38).

INITIATIVES IN THE AREA OF TRAINING, EDUCATION, AND SCIENCE		SCORE BY DISCIPLINE
		Agricultural Sciences	Natural Sciences	Health Sciences	Social Sciences
1	Encourage a change in the system of values regarding food to prioritise people’s health and the health of the planet.	6.17	7.83	7.50	7.31
2	Promote effective legislation/regulation of food information in labelling and/or advertising.	6.83	5.33	7.08	7.00
3	Provide sufficient, verified, and accurate information on food and the food system.	7.17	7.00	5.42	6.92
4	Promote the coordination and integration of the different scientific disciplines working on sustainable and healthy food.	5.83	4.50	5.50	5.15
5	Promote a cross-cutting food education for all citizens.	4.67	8.83	5.67	7.31
6	Create a specific logo to distinguish sustainable and healthy foods.	2.33	3.00	4.17	4.31
7	Enhance the role of nutritionists in schools and introduce nutritionists in public health services.	3.67	5.67	5.50	3.77
8	Strengthen the socio-cultural and environmental dimension in food research and recommendations to consumers.	5.00	4.00	5.42	5.46
9	Improve accessibility to the results of research on sustainable and healthy food and promote its dissemination among the public.	6.00	5.17	4.83	3.54
10	Promote knowledge and appreciation of the rural environment and the agri-food system.	7.33	3.67	3.92	4.23

,

Table A4. Average score by discipline on initiatives to promote a sustainable and healthy diet in Spain in various aspects of the food system. (N = 38).

INITIATIVES IN VARIOUS ASPECTS OF THE FOOD SYSTEM		SCORE BY DISCIPLINE
		Agricultural Sciences	Natural Sciences	Health Sciences	Social Sciences
1	Establish measures to make sustainable and healthy food accessible and affordable for all citizens.	7.33	10.00	9.83	8.77
2	Monitor and follow up existing measures to promote sustainable and healthy food (e.g., PAOS, campaigns against food waste, self-regulation of food advertising, etc.).	4.00	5.17	4.75	4.08
3	Tax unhealthy foods with a high environmental impact.	5.50	5.17	6.17	6.38
4	Promote the agroecological transition of production systems.	7.17	3.00	7.58	6.62
5	Design a territorial model to reduce depopulation and maintain agricultural activity.	4.83	4.67	3.92	6.08
6	Promote and reappraise local, artisanal, and organic agri-food production.	7.83	5.00	5.42	5.69
7	Implement measures to encourage the consumption of sustainable and healthy foods.	5.83	9.00	8.08	7.08
8	Generate market opportunities so that the different actors in the food system can move towards sustainable and healthy food models.	6.00	5.00	4.92	5.69
9	Orient agri-food companies’ Corporate Social Responsibility action towards sustainable and healthy food.	5.00	6.17	3.83	3.08
10	Promote short food supply chains and local trade.	5.50	6.17	4.92	5.77
11	Encourage public procurement of sustainable and healthy food in public institutions (hospitals, schools, care homes, prisons, etc.).	7.00	6.67	6.58	6.77

and

Table A5. Average score by discipline on initiatives to promote a sustainable and healthy diet in Spain in the area of governance and the framework of relations between actors within the food system. (N = 38).

INITIATIVES IN THE AREA OF GOVERNANCE AND THE FRAMEWORK OF RELATIONS BETWEEN ACTORS WITHIN THE FOOD SYSTEM		SCORE BY DISCIPLINE
		Agricultural Sciences	Natural Sciences	Health Sciences	Social Sciences
1	Promote spaces that foster smooth collaboration and communication between the different actors in the food system.	7.33	6.83	5.83	5.77
2	Build multi-stakeholder and multi-level governance structures.	7.00	4.67	6.00	6.08
3	Encourage the scaling up of successful initiatives on sustainable and healthy food.	4.83	5.83	5.25	5.31
4	Modify the current structures of government, seeking coordination and integration of responsibilities and jurisdictions, and mainstreaming its activities.	5.83	5.17	5.42	6.69
5	Give greater powers to the Spanish Agency for Food Safety and Nutrition.	2.50	6.00	5.33	4.46
6	Promote private governance mechanisms (standards, certifications, seals, etc.) in the promotion of sustainable and healthy food.	3.67	3.67	2.92	2.46
7	Create a new Ministry or General Secretariat with the specific task of promoting sustainable and healthy food and with the capacity and authority to work on this issue as a whole.	3.33	2.50	4.58	3.69
8	Promote interaction between civil society initiatives and networks developing sustainable and healthy food initiatives.	5.33	5.67	4.17	4.54
9	Promote the creation of local food policies and councils.	5.17	4.67	5.50	6.00

).

3. Results

This section presents the results of the experts’ concept of a Sustainable Healthy Diet. Secondly, it describes the main problems they identify in promoting SHDs in Spain. Thirdly, it explores the initiatives that, in their opinion, should be encouraged to promote SHDs in Spain. In each sub-section we examine the areas where the experts approach agreement, but also the aspects in which the disciplines differ from each other.

3.1. Aspects of Sustainable Healthy Eating

Experts referred to several of these aspects when formulating an SHD, developing complex definitions of SHDs, composed of multiple interconnected aspects. Most of them stressed that an SHD should be made up of healthy and nutritious food with a low environmental impact. They believed that these two dimensions should be considered in a holistic manner given their impact on public and global health. Several experts considered that, in addition, an SHD must also consist of foods that are culturally acceptable and socially appropriate. Other aspects that appear, albeit to a lesser extent, are justice, equity, availability, and affordability. The replies also indicate that the definition of an SHD should incorporate a systemic vision that takes account of the different actors and processes involved in the food system and the relations between them. An example of this is the idea stated by an expert in sociology and agricultural economics: ‘It is a system that enables all people to have access to food that meets their health needs, nutritional needs, and cultural preferences. A system in which citizens can say what they want to eat and know the social and economic ecological footprint along the chain and can meet their needs in a fair and sustainable way’.

Several of the interviewees referred, explicitly or implicitly, to the FAO definition, because they considered that it includes many of the dimensions associated with the concept of healthy and sustainable food. An expert in urban planning, land-use planning, and agroecology commented: ‘I think that the FAO definition is quite satisfactory. In other words, a sustainable food model is one that guarantees appropriate and nutritious food for all people, and this implies an inter-generational responsibility. In other words, “all people” are not only those of us who are on the planet now, but also future generations. And also inter-territorial—not feeding ourselves in some territories at the expense of others. We must stop plundering, exploiting, over-exploiting others. And this implies ecological responsibility. So that’s how it is, basically’.

Nevertheless, some scientists clearly continue to have a more restrictive conception of an SHD, focusing only on health or only on sustainability, or focusing only on one phase of the food chain. One scientist, for example, was an expert in zootechnics, who said: ‘I don’t work on food so much as on the aspect of producing food in a sustainable way. So I don’t know if you want me to answer about food models—where I would be talking more as a consumer—than about sustainable models of food production’.

Taking the answers obtained in round one as a starting point, we set up the items for Section one of the questionnaire. The results of rounds two and three show that, for the 38 participating experts, the main dimensions making up an SHD (Table 2) were that it should be ‘Based on nutritious food ensuring an optimal state of health’ (mean score of 14), have a ‘Low environmental and climate impact’ (13.68), and be ‘Safe and secure’ (13.13). The fourth dimension included in the 75th percentile was being ‘Affordable’ (10.97) in round two and being ‘Available and accessible’ in round three (10.92). There is, therefore, a high degree of agreement among experts on the three fundamental dimensions of SHDs: the nutritional and health aspects, the environmental aspects, and safety in a broad sense, both food safety and food security.

The analysis of the responses according to disciplinary groups (Figure 1 and Table A1 in the Appendix A) shows that, for three of the four dimensions with the highest scores (items one, four, and 15), the Natural Sciences group gave the top ratings. Furthermore, there was a high degree of agreement among experts, irrespectively of disciplinary group, in giving low importance to governance and animal welfare aspects (items 16 and 18) when conceptualising SHDs.

The breakdown shows that there are also divergences between disciplines, as there are aspects where some groups are separated from the rest, reflecting the particular views of each disciplinary field. Dimension eight, ‘Low presence of animal protein’, yielded a large interdisciplinary gap, especially in the importance given to it by experts in Health Sciences and the lower relevance given to it by experts in Agricultural Sciences. The Natural Sciences experts stood out from the rest in the attention they gave to dimension three, ‘Reduction and optimisation of food waste’, and in showing less interest in dimensions five and seven, ‘Local or short supply chain’ and ‘Socially appropriate and culturally acceptable’. Researchers in Agricultural Sciences were distinguished from the others by their special interest in item 13, ‘Reduced presence of pesticides and antibiotics’, while experts in the Social and Human Sciences attached the least importance to the most consensual item, number four, ‘Based on nutritious food ensuring an optimal state of health’.

3.2. Obstacles to Promoting Health and Sustainable Food in Spain

In round one, the experts emphasised that the main problem they identify is the actual functioning of the globalised food system and its opacity. These characteristics, in their opinion, prevent the development of a systemic vision of how the food system functions and its impact, as well as a shared conception of an SHD. The most frequently mentioned barrier is business corporatism and the pressure exerted by certain actors in the agri-food chain (especially in the food industry and food distribution) to prevent a transition towards more sustainable and healthier food models. A food technology expert summarised it thus: ‘I think there is, on the one hand, a barrier from the industry’s point of view, in the sense that there are food sectors that are powerful commercial sectors. Food is an important part of the GDP, so there are sectors that exert pressure every time a measure is put in place that could be detrimental to them as a sector. Then they immediately take refuge in: “We are a source of employment and therefore we cannot be attacked’.

Another frequently mentioned obstacle is the absence of a regulatory framework to implement measures limiting the production, distribution, and sale of unhealthy and unsustainable food, and to promote the production, distribution, and sale of healthy and sustainable food that is socially and culturally appropriate at a good price. Barriers linked to the current framework of governance for the food system are also mentioned, highlighting the lack of dialogue between the different actors in the food system and the poor coordination between public bodies working on food. This, say the experts, leads to disorganised and inconsistent, sometimes even incompatible, policies. They highlight the lack of bottom-up and/or innovative governance mechanisms encouraging the participation of other actors in the food system. They also point out that one of the main problems in achieving an SHD is the Spanish public’s lack of education on the nutritional aspects of food and on how mechanisms of the food system function. However, it is not only a lack of education that is mentioned, but also the fact that the information available on these issues is scant, contradictory, and they point out, in many cases poorly fact-checked.

In short, there is significant agreement on the obstacles in the way of progress towards healthy and sustainable eating. In the opinion of the experts consulted, these barriers are located at various levels of the system: at the level of the food system, meaning problems of functioning and opacity, and the power of particular agents (industry and distribution); at the level of the state, indicating lack of regulation; and at the level of consumption, referring to the public’s lack of training and information. It is, therefore, not surprising that a lack of dialogue between the actors in the food system is also presented as one of the main barriers to achieving the objective of an SHD.

As happened when looking at the principles informing an SHD, when the obstacles highlighted in the interviews are broken down by disciplines, we observe that the deeper that experts go into their evaluation, the more they tend to highlight the aspects that relate to their respective disciplinary orientations. Only experts in Social Sciences drew attention to barriers concerning governance, which received no attention from the rest of the experts. The opposite was true for barriers related to training and information, which were highlighted exclusively by experts in the Natural Sciences and in the Health Sciences. This issue is recognised by the researchers themselves, as an expert in agricultural economics and sociology pointed out: ‘We researchers also have our prejudices, and we have our own discourses and narratives. And we often find it very, very difficult for anyone to get us out of them. And we have discourses, purer discourses of food sovereignty or discourses of the, of the even more extreme agro-industrial model, relying on research in relation to the large multi-national seed or input-supply companies. And often all of this is very polarised. And there are difficulties in finding common ground’.

The 49 barriers identified in round one were grouped into thematic blocks and a closed question with 18 items was designed for rounds two and three (Table 2). The results of these rounds (with slight changes between them that do not affect the configuration of the percentiles) show that the four fundamental barriers hindering the promotion of SHDs in Spain are identified as follows: item 14, ‘Strong influence of the food industry and large-scale distribution on the configuration of production, distribution, purchasing habits, and food policies’ (average score 15.11); item 11, ‘Lack of political ambition to implement effective measures to promote sustainable and healthy food’ (average score 13.42); item six, ‘Poor regulation of unsustainable and unhealthy food, and lack of enforcement measures’ (average score 11.92); and finally, item 13, ‘Healthy and sustainable food is not accessible and affordable for a significant portion of the population’ (average score 11.82).

The analysis by discipline (Figure 2 and Table A2 in the Appendix A) shows that experts in Health Sciences were responsible for the highest scores for three of the consensus variables (14, 11, and six). The barrier with the highest consensus was 15, ‘Initiatives to promote sustainable and healthy food promoted by citizens and social organisations are co-opted by the dominant system’. There was less divergence between the disciplines with respect to barriers than when considering the principles of an SHD. The one showing most divergence was item 16, ‘The level of food education of the public is low’, where the importance given to it by those in Natural Sciences was at the opposite extreme from the low score given to it by Health Sciences. Something similar occurred with item two, ‘Information on food and the food system is limited, confusing, and inaccurate’, as experts in Agricultural Sciences placed it higher than those in Health Sciences, who gave it the least importance. We note that Agricultural Science experts gave a considerably lower rating than the rest to item seven, ‘Measures to promote healthy and sustainable food centre on individual consumer choices’. The same is true for those in Health Science with respect to item 17, ‘Primacy of urban over rural needs’. These data underline that disciplinary boundaries and specialisations persist in certain topics of analysis, but also show that specialisation does not stop the experts from recognising the main issues and agreeing on the barriers blocking action.

3.3. Action to Promote Healthy and Sustainable Eating in Spain

In round one, most of the experts interviewed established a sequence of ideas in which they connected the barriers they had previously identified with the action that they proposed to promote healthy and sustainable food in Spain. They proposed measures to promote food education in a cross-cutting manner, as well as to improve information about food and the food system. They also pointed to the need to launch initiatives to drive transformations in the food system, acting on all the component phases and specific processes, which include valuing the rural environment and its contributions to SHDs; promoting local, artisanal, and low-mileage production; promoting short distribution chains; and encouraging changes in eating habits.

Legislative, financial, and regulatory action also received much attention, with proposals to impose higher taxes on unhealthy foods and foods with a high environmental impact, and to control or limit the power of certain actors. Experts stressed the need to adopt binding minimum standards for all actors in the food system to make food healthier and more sustainable, and to set up measures to promote equal and equitable access to food. Some even believed that the measures should go both ways: ‘I believe that an umbrella policy that we must dare to use in a powerful way is fiscal policy. A fiscal policy that, as I said before, acts on the externalities, on health and the environment of certain models of production, logistics, and marketing. In other words, those who pollute, should pay. Those who conserve, should get paid… For me, fiscal policy is perhaps the, the great policy…. with all its complexity, the one that would answer all these needs’ (expert in agricultural economics and sociology).

Other proposals focus on modifying the framework of governance and of relations between actors in the system. They also refer to the need to find points of convergence and create initiatives for articulation between the different actors based on innovation and the co-creation of solutions, as well as to explore new, more innovative frameworks of governance that modify the current structures of government. This is because they consider that the promotion of healthy and sustainable food models requires an inter-departmental approach and coordination between areas so that the response is comprehensive and coherent, as reflected in this comment: ‘it is an issue that is there and that involves different ministries and different government departments… Then the Autonomous Communities [regional governments] also have responsibilities in this area. I would even include the local councils to promote… So this should be a policy that covers everyone and everything. It has to be well integrated, not everyone… seeing things from their own point of view. And in the end… it comes to nothing. Because this requires an inter-disciplinary and inter-departmental, inter-ministerial, inter-government-department approach so that, perhaps, it gets a coherent response’ (expert in legal sciences).

Several experts indicate the need to implement measures to modify the framework of relations among researchers working on food issues, as well as between scientists, government, and other stakeholders: ‘we should make a greater effort to communicate with other actors and perhaps also change the focus by looking at the field of research we dedicate ourselves to… beyond publishing research results, I think it is also important to be in contact with actors who can then perhaps do something with your results. Or even try to… In addition to writing scientific publications that we often know are not accessible to anyone other than scientists, try to write reports or articles that get the message across and show the reality of the results and the action that should be taken or that it would make sense to take to improve this situation’ (nutrition expert).

The 58 measures identified in the first round were grouped into three thematic blocks that were independently tested in rounds two and three. In the thematic block dedicated to action in the field of training, education, and science (Table 2), the experts agreed on the importance of initiative one, ‘Encourage a change in the system of values regarding food to prioritise people’s health and the health of the planet’, with a score of 7.29 in both rounds, and initiative two, ‘Promote effective legislation/regulation of food information in labelling and/or advertising’, with an average score of 6.82.

The analysis by discipline shows that the initiative that received the greatest consensus among experts was to ‘Promote the coordination and integration of the different scientific disciplines working on sustainable and healthy food’ (Figure 3 and Table A3 in the Appendix A). The initiative with the greatest variation between disciplines was number five, ‘Promote cross-cutting food education for all citizens’, where the difference is significant, especially between those in Natural Sciences, who gave the highest scores, and those in Agricultural Sciences, with the lowest scores. With respect to the rest of the disciplines, experts in Agricultural Sciences stand out for giving more importance than others to initiative ten, ‘Promote knowledge and appreciation of the rural environment and the agri-food system’. And the experts in Social and Human Sciences gave lower scores to initiative nine, ‘Improve accessibility to the results of research on sustainable and healthy food and promote its dissemination among the public’.

In the thematic block referring to action to promote changes in the different aspects of the food system (Table 2), convergence was established around initiative one, ‘Establish measures to make sustainable and healthy food accessible and affordable for all citizens’ (average score 9.00); initiative seven, ‘Implement measures to encourage the consumption of sustainable and healthy foods’ (average score 7.61); and initiative 11, ‘Encourage public procurement of sustainable and healthy food in public institutions (hospitals, schools, homes, prisons, etc.)’ (6.79).

The breakdown by discipline (Figure 4 and Table A4 in the Appendix A) shows that the third most prioritised initiative was the one with the greatest general consensus among all disciplines: initiative 11, ‘Encourage public procurement of healthy and sustainable food in public institutions (hospitals, schools, care homes, prisons, etc.)’, while the second most prioritised initiative seven ‘Implement measures to encourage the consumption of sustainable and healthy food’, was the one with the greatest variation among disciplines, together with nine, ‘Orient agri-food companies’ Corporate Social Responsibility action towards sustainable and healthy food’. In both cases, they received a higher score from experts in Natural Sciences, while the lower score came in the first case from those in Agricultural Sciences and in the second case from those in Social Sciences. Initiative six, ‘Encourage and reappraise local, artisanal, and organic agri-food production’ was the most important for experts in the Agricultural Sciences, while number four, ‘Encourage production systems to make a transition to organic agriculture’ received the least attention from the Natural Sciences, with other discipline groups valuing it more highly.

In the thematic block that refers to action in the area of governance and relations between actors in the food system, the two initiatives in this block that elicited the greatest consensus among the experts (Table 2) were those related to the creation of networks between stakeholders in the food system: items one, ‘Promote spaces that foster smooth collaboration and communication between the different actors in the food system’ (with an average score of 6.21), and two, ‘Build multi-stakeholder and multi-level governance structures’ (5.95).

The analysis by discipline (Figure 5 and Table A5 in the Appendix A) shows that it was the experts in Agricultural Sciences that gave the greatest weight to the two initiatives with the highest scores. The Social Sciences experts stand out for prioritising, in first place, item four, ‘Modify the current structures of government, seeking the coordination and integration of responsibilities and jurisdictions, and mainstreaming its activities’. The initiatives that received the greatest consensus among all disciplines were item nine, ‘Promote the creation of local food policies and councils’ and item three, ‘Encourage the scaling up of successful initiatives on sustainable and healthy food’. The greatest degree of variation in the experts’ scores was found on item five, ‘Give greater powers to the Spanish Agency for Food Safety and Nutrition’. As we have seen, those in Natural Sciences prioritised this action, while those in Agricultural Sciences gave it a significantly lower score. The polarisation between the two disciplines is similar but reversed on item two ‘Build multi-stakeholder and multi-level governance structures’, which was rated highly by those in Agricultural Sciences, but much lower by those in Natural Sciences.

As our analysis shows, beyond the initiatives that show a consensus among all disciplines, each discipline opted for different proposals. The experts in the Agricultural Sciences attached more importance than the others to modifying the governance framework by promoting innovative, multi-level, and multi-actor frameworks. Experts in Natural Sciences favoured maintaining the current framework, but extending the jurisdiction of the Spanish Agency for Food Safety and Nutrition. The experts in Health Sciences were the most interested in promoting a vertical and centralised governance framework through the creation of a new structure (a ministry or general secretariat). And the experts in Social and Human Sciences focused on two issues linked to their disciplinary field: the transformation of government structures with a view to mainstreaming and integrating them, and the promotion of policies and structures at a local level.

4. Discussion

The results of the Delphi survey show that there is a consensus among experts on the definition of a Sustainable and Healthy Diet, as well as on the factors that prevent it from being put into action and the measures that could favour it. According to the consensus definition generated by our research, an SHD is characterised by being based on nutritious foods that have low environmental impact, that meet safety and security guarantees, that are available, accessible, and affordable for the public. A significant number of the experts stress that it is a multi-dimensional concept that requires a systemic approach. They therefore move away from restrictive frameworks of analysis and align themselves with the broad visions of SHDs emphasised by Garnett [12] and Lang [13]. We also see that they converge around the definition of an SHD proposed by FAO-WHO, which some even explicitly mention. This seems to indicate that there is some academic consensus on the usefulness and relevance of this definition, at least as a starting point.

In their evaluation of the barriers, there is also an important level of consensus among the experts. They confirm the capacity of the food industry and food distribution to influence matters, and the opacity of these two groups of actors emerges as an obstacle. The experts also point to the difficulties that governments face in promoting an SHD. They therefore pay special attention to regulatory aspects and structural dimensions, focusing mainly on the role of three actors: government, the food-processing industry, and food distribution. These are aspects that have been emphasised by Boylan et al. [16], who highlight the absence of government regulation and the conflicting agendas between the health sector and food industry as the fundamental barriers they identified in Australia. They also point to the lack of dialogue between the agents, which the experts themselves mention as impeding progress in a coordinated direction, in line with the observations of [42,45].

The disciplines also converge in identifying the main areas for action: education, the functioning of the food system, and the framework of governance. The proposals they agreed on advocate promoting a change in values in the public to prioritise global health, improving and regulating information on food, and establishing regulatory measures (legislative, fiscal) that facilitate an SHD for all. These results are in line with those of Eurobarometer 505 [14]. The experts also highlighted the importance of creating spaces that foster dialogue and collaboration between the different actors in the food system, as well as the promotion of governance frameworks that are horizontal, multi-level, and multi-actor in nature, in line with the importance that this focus has acquired among academics [42,57].

In agreement with the literature [12,13,16], this paper has found that divergence according to discipline persists in scientists’ assessment of SHDs. Although there is a multi-dimensional and systemic view of SHDs overall, round one showed that there are experts who take a more restrictive approach to the concept of an SHD [12] by focusing only on one or two dimensions: ‘health’ or ‘environment’. This shows that these two lines of ‘traditional’ studies on SHDs [21,37] are still alive, as is the low importance given to socio-economic aspects [9,23].

In all the areas analysed—aspects of the SHD, obstacles impeding it, and initiatives to advance it—the disciplines that are most polarised are the Agricultural Sciences and the Natural Sciences, as these experts gave the most extreme scores, and therefore had the most restrictive or least systemic vision and, in some cases, were significantly different from the rest of their colleagues. In contrast, experts from Social Sciences and Health Sciences tended to occupy intermediate positions in the scores, which could indicate that there is a certain shared vision between these disciplines or, at least, agreement on certain issues. In fact, it seems that the nutritional dimension has entered the agenda of the other scientists, while those in Health Sciences are showing more interest in environmental issues. Such a critical consensus was already detected by Boylan et al. [16] in their Delphi study with policy-makers.

5. Conclusions

The results of this study have allowed us to explore the views on SHDs of researchers from different disciplines working on this issue in Spain and to analyse the factors that, in their opinion, hinder and favour the promotion of an SHD in the Spanish context. To conclude the paper, we summarise the main ideas in reference to methodological and policy implications.

5.1. Methodological Implications

Despite the identified points of convergence, the distance between disciplines in their understanding of SHDs and how to achieve them, has not disappeared, although it is more evident in the experts’ individual discourses (collected in the interviews in round one) than in the process of ‘consensus-building’ and putting together a collective opinion (facilitated by the Delphi technique in rounds two and three). Nor are the differences in opinion always related to their areas of expertise. This may indeed show that scientists who specialise in the study of food are open to reflection on food issues and do not limit themselves to matters strictly related to their discipline. It should be noted, however, that this survey has taken place in the multi-disciplinary environment facilitated by the Delphi method. With this method, the different disciplines are able to acknowledge the complexity of the object of study and confirm that the distances between them are reduced when they come closer to the views of other scientists. It is, therefore, worth reflecting on whether the working method itself ‘forces’ consensus as the different rounds of the survey progress, and whether there may have been a self-selection bias, since it is highly likely that the experts who agreed to participate in the study were particularly motivated by the subject matter of the study and more open to sharing their opinions with other scientists than those who refused to participate. The uneven disciplinary distribution of rounds 1 and 2, with greater participation by experts in Social and Health Sciences and less participation by experts in Agricultural and Natural Sciences, may also have influenced the weight given to certain topics of debate.

5.2. Policy Implications

Achieving SHDs is a goal of public policy programmes aiming to improve human and planetary health. Scientific knowledge can inform the direction of these actions, being used by governments to design food and sustainability policies. This study suggests that the scientists share a multi-dimensional view of SHDs and believe that a systemic approach is needed. Adherence to the FAO-WHO definition also shows how the agenda of international organisations has been successfully incorporated into the Spanish scientific agenda. This consensus around the same area of study constitutes a solid basis for research on SHDs and minimises the effects of scientists in different disciplines having a siloed vision of food problems, though this still persists among the experts consulted.

The formulation of barriers and possible pathways towards SHDs by respondents, indicates that researchers are aware of the web of relationships between actors in the agri-food system. All disciplines highlight the dominant position of some actors in the food system and consider that their position of power generates blockages to achieving an SHD. Scientists also believe that these blockages could be minimised through institutional intervention. And, although they criticise government’s lack of action, it is to government that they look to take on the role of regulator. In this regard, they consider that one of the main areas of policy action is changing the relations between actors in the food system and exploring innovative frameworks of governance.

One aspect that should be examined further in future research is the fact that the scientists consulted barely mention the role of science as an agent for transforming the food system. They do not perceive themselves as part of the problem nor, therefore, as part of the solution to promoting healthy and sustainable food policies. They seem to consider science as a tool for interpretation, but not as an object of study in itself. Further disciplines could also be consulted, such as philosophy of science. These results provide the basis for future studies to explore the role of science as a transformative agent in the food system in depth.