Morgane Innocent

Samuel Guillemot

Patrick Gabriel

Speeding up the transition to a more sustainable food system: new insights into the links in a system of practices

Keywords: Sustainable food, Theory of social practices, System of structural equations, Interpretative approach, Food systems article

More sustainable food choices are part of a complex system that combines practices, which themselves are interconnected in a network of elements made up of competences, meanings and material devices. The present article proposes an innovative method for studying this system through a non-deductive quantitative approach. The research adds to the corpus of the 'theory of practices' by defining the concepts of 'central' practices (i.e., connected to many elements of the system, such as the practice of buying and cooking sustainable products in the sustainable food system) and 'peripheral' practices (i.e., connected in a lesser extent to other elements of the system, such as the practices of anti-waste, growing your own food, and the consumption of plant proteins). It also highlights the 'connector' role between the practices of certain elements. Finally, based on the current structure of the system of sustainable food practices, the article makes several propositions for speeding up change.

When over one third of greenhouse gas emissions caused by human activities are foodrelated [START_REF] Crippa | Food systems are responsible for a third of global anthropogenic GHG emissions[END_REF], moving towards a sustainable food system becomes a key transition. However, food is about more than just what we eat: it includes the food we buy, where we buy it, how we prepare and cook it, and even how we store it and manage the waste it produces. A French Senate report about moving towards a sustainable food supply (Vers une alimentation durable) [START_REF] Cartron | Towards sustainable food: A major health, social, territorial and environmental challenge for France. Information report on behalf of the Senate's Forward Studies Delegation[END_REF] considers food, or the 'food system', to be all of the actors and activities that play a part in feeding human beings, from farm to fork. This naturally places food at the heart of sociological, health-related, ecological and economic issues, and helps to guide thinking towards a more sustainable food system.

In response to these challenges, and at the consumer level, guiding people's behaviours towards sustainable food usually involves changing their food system by changing practices that are mostly daily (purchase location, purchase type, meal preparation method, etc.) and interdependent. For example, meal preparation depends on an individual's competences and influences purchase location. The theory of social practices is used in this study to understand the system individuals fit into, and is increasingly used by researchers in sociology and consumer behaviour to analyse the current changes in energy, ecological and societal transitions (e.g. [START_REF] Halkier | A practice theoretical perspective on everyday dealings with environmental challenges of food consumption[END_REF][START_REF] Plessz | La théorie des pratiques. What contributions for the sociological study of consumption?[END_REF][START_REF] Evans | Constructing and mobilizing 'the consumer': Responsibility, consumption and the politics of sustainability[END_REF][START_REF] Roques | Energy consumption and theory of practice: towards courses of action for the energy transition[END_REF]. It provides a theoretical framework for mainly qualitative approaches and therefore allows changes in practices to be described in depth and in detail. The drawback, however, is that sometimes these studies are not enough to convince decision-makers, in particular public authorities, of the transferable and generalizable nature of the knowledge produced and of its value for decision-making.

In this theoretical framework, the emergence of a new practice is understood through a reconfiguration of the roles perceived by the actors based on interactions between elements such as material devices and objects used, attributed meanings (social and personal), and the actors' competences and knowledge [START_REF] Shove | Consumers, Producers and Practices: Understanding the Invention and Reinvention of Nordic Walking[END_REF]. Even though these roles can be perceived and understood through a qualitative methodology, a quantitative methodology would make it possible to clarify the importance of the interactions between the practice's elements. However, estimating how influential these elements are in the evolution of the practice remains a challenge and it is still difficult to operationalize the theory to provide answers to the fundamental issues specific to a sustainable marketing approach. This study will address these challenges and consider how consumers can be encouraged to adopt sustainable food practices. More specifically, it will examine the drivers that should be used for encouraging people to engage in more sustainable food practices.

The first objective of this article is theoretical. Understanding a practice means setting out the links between the elements of that practice. Identifying the possibilities of increasing the sustainability of a food practice also means establishing a hierarchy between the elements according to the contribution they make to a sustainable food practice. The contribution of this research is therefore twofold: firstly, it allows us to unpack the system of sustainable food practices, and secondly, it adds to the corpus of practice theory by highlighting 'core' practices in a system and their relationship to 'peripheral' practices. Our results indicate that in the case of the sustainable food system, the central practice consists of actions around buying and cooking sustainable products, and the periphery practices are anti-waste, growing your own food and the consumption of plant protein.

The second objective is methodological. Identifying the contributions of the basic sets in a food ecosystem as it transitions towards greater sustainability involves studying practices from an original methodological angle, thus making it possible to take a more detailed look at potential incentive drivers. Gaining an understanding of an ecosystem is almost always done through a qualitative approach from an interpretative angle [START_REF] Robert-Demontrond | Principles, issues and limits of the theory of practice for marketing[END_REF]. However, such approaches struggle to measure the links between the system's elements, which then makes it difficult to make recommendations about overall performance. The originality of the present study is that it adopts a quantitative and interpretative approach, by using an inductive quantitative approach adapted to the theory of social practices, to examine several alternative theoretical models in great detail. This positioning is based on studies in the discipline that call for quantitative approaches to be used less often (Brabet, 1988;[START_REF] Galan | A deconstruction of measurement tools in marketing[END_REF]. The aim of this research is to build theory and is part of an exploratory approach. Although these approaches are often associated with qualitative methods, according to [START_REF] Hammersley | Deconstructing the qualitative-quantitative divide[END_REF], there are other objective-method combinations that are perfectly reasonable.

The third objective is managerial. It aims to provide concrete solutions to speed up changes in sustainable food practices by distinguishing the drivers to be used to encourage such practices. These incentive drivers are directed at consumers, but are also used by different stakeholders in the food system: industrialists and distributors participating in economic and regional dynamics, and public authorities, via incentive and support policies. The results of the study show in particular that competences are a key element in sustainable food practices, thus supporting the idea that enhancing consumers' food sustainability competences is a major driver for speeding up change. Empowering all of these actors to work towards a sustainable food system in a way that has a positive impact on their well-being, on society and on the planet, thus places this research and its managerial objective in the framework of responsible marketing research, according to [START_REF] Haenlein | Guest Editorial: Responsible Research in Marketing[END_REF].

The article proceeds as follows: after presenting a state of the art and current knowledge on the system of sustainable food practices, and the strengths and limitations of using the theory of social practices, the methodology and results are presented in detail. The final section discusses interpretations and implications of the results obtained, and the conclusion addresses how these implications can be exploited to speed up transitions.

Understanding the system of food practices through the theory of social practices Conceptually, 'food' is a term with multiple interpretations. It can refer to eating behaviours, to emphasise the activity of eating, which also includes purchasing and preparing food [START_REF] Dyen | Modifying food practices from the reality of routines. A practice-based approach[END_REF]. More generally, as advocated by Senators Cartron and Fichet in their report (2020), 'food' can be replaced by the term 'food system' and can encompass all actors and activities that contribute to feeding human beings. These conceptions underline that the content of people's plates is strongly linked to specific social and identity frameworks, particular material facilities and purchase environments, and lifestyles. We will therefore use the term 'system of food practices' to take account of the integration of food in an interconnected network of competences, meanings, material and human devices.

Sustainable food

From the consumer's perspective, understanding the subject of sustainable food implies taking into account all food practices that have an impact on ecological transition [START_REF] Verain | Sustainable food consumption. Product choice or curtailment?[END_REF][START_REF] Whittall | Public understanding of sustainable diets and changes towards sustainability: A qualitative study in a UK population sample[END_REF]. In terms of environmental impact assessment, product life cycle analysis is the methodological reference (Institute for Environment and Sustainability, 2010). It addresses the issue from different stages of the food's life, over a person's life span (ADEME, 2016(ADEME, , 2018)). This is why sustainable food encompasses a very broad scope, combining (1) diet, (2) product choices, and (3) domestic practices that emit little (or less) greenhouse gases (GHGs), but are also less resource-intensive and less polluting.

Sustainable diet Today, this mainly concerns the moderation of animal protein-based foods, which are high emitters of GHGs, notably through flexitarianism or the more radical and less frequent vegetarianism or veganism (Biermann and Rau, 2020;[START_REF] Xu | Global greenhouse gas emissions from animal-based foods are twice those of plantbased foods[END_REF][START_REF] Laisney | Vegetarianism and flexitarianism, an emerging trend[END_REF][START_REF] Mathieu | Végétarisme, végétalisme, veganisme: des comportements (alimentaires) au service de l'identité? Une étude qualitative en population française[END_REF]. However, introducing products with a high nutritional value into one's diet, and moderating one's diet in general, is also part of the definition of these diets. Finally, and this is connected to the second aspect of sustainable food, sustainable diets also include the notion of seasonal produce and are therefore more often local, less processed and less packaged (Haut conseil de la santé publique, 2017; WWF and Eco2 Initiative, 2017;[START_REF] Fardet | Holistic Nutrition: Towards a healthy, sustainable and ethical preventive diet[END_REF].

Sustainable food products are defined through more sustainable production, processing and distribution. This includes labelled productssuch as organic productswhich act as product guarantees, or their composite ingredients that are grown without synthetic chemicals, without GMOs and that preserve animal welfare in the case of livestock farming [START_REF] Sommier | Organic food consumption as a total social fact. An ethnomarketing analysis of Biocoop customers[END_REF]Agence Bio, 2021); or North-South and North-North fair trade products based on fair remuneration for producers and respect for the environment (WFTO, 2017), and sustainable fishing labels. Sustainable food products are also characterised by their minimal processing, a guarantee that nutritional content is preserved [START_REF] Fardet | Holistic Nutrition: Towards a healthy, sustainable and ethical preventive diet[END_REF], and by low-impact [START_REF] Guillard | The Next Generation of Sustainable Food Packaging to Preserve Our Environment in a Circular Economy Context[END_REF], minimal packaging, and packaging-free refillable groceries [START_REF] Reniou | Le marché du vrac : un renouveau des pratiques, in Dekhili S, Le marketing au service du développement durable: Repenser les modèles de consommation[END_REF]. In the category of sustainable products, local products are included, even if the link between short local circuits and a better environmental balance can only be proved under certain conditions (ADEME, 2017), although they are a strong marker of sustainability for consumers (Abid et al., 2020).

Finally, sustainable uses in the home will be influenced by certain choices made during purchase: mobility, frequency, growing your own food, etc. ( [START_REF] Van De Walle | Le difficile pari des « courses durables » hors des centres-villes[END_REF]. The sustainability of these uses will also depend on less waste-generating behaviours (Le [START_REF] Borgne | Les internautes face au gaspillage alimentaire[END_REF], related to product storage [START_REF] Farr-Wharton | Identifying factors that promote consumer behaviours causing expired domestic food waste[END_REF], and also ways of cooking [START_REF] Evans | Blaming the consumer-once again: the social and material contexts of everyday food waste practices in some English households[END_REF][START_REF] Halkier | A practice theoretical perspective on everyday dealings with environmental challenges of food consumption[END_REF]. Finally, food sustainability also includes waste management through sorting [START_REF] Monnot | Household waste sorting: a characterization of the logistics deployed by consumers[END_REF].

According to [START_REF] Hennchen | Knowing the kitchen: Applying practice theory to issues of food waste in the food service sector[END_REF], most studies seeking to understand the drivers of food trends and how to exert a greater influence over them so that they move towards greater sustainability come up against a difficulty which arises from adopting the same cognitive assumption: increased knowledge leads to better decisions (for example, by favouring healthier products), through more rational behaviours. Thus, 'traditional' recommendations lead to improving information with the actors, and where appropriate are accompanied by intrinsic incentives (healthy diet). Clearly, according to the results of a study by the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) (INCA3, ANSES, 2017), this cognitive orientation does not appear to be sufficiently effective: it does not automatically follow that information made available will be used, and therefore, consumer guidance needs to be provided at the same time. Nudges have been shown to be effective in several contexts, such as out-of-home catering, to improve food choices [START_REF] Cadario | Which healthy eating nudges work best? A meta-analysis of field experiments[END_REF]. However, authors have highlighted their limitations because the effects diminish over time and may not be well accepted by the target audience. Here again, nudges used alone are not enough and education, including more transparency in the objectives of operations, is necessary (Cadario and Chandon, 2019;[START_REF] Girardon | La prise en compte du niveau de connaissance préalable des individus dans l'efficacité des nudges : une application au tri des déchets en Corse[END_REF]. More social approaches can therefore be recommended, and adapted to the understanding of food patterns. The field of study of such approaches is a community of individuals, the phenomenon studied is then the food pattern shared through rules of action, norms and values that have been collectively adopted. However, as food habits are rooted in specific conventions and cultures, their evolution seems slow.

Theory of Social Practices (TSP)

The advantage of TSP is that it builds on previous orientations [START_REF] Robert-Demontrond | Principles, issues and limits of the theory of practice for marketing[END_REF]: it recognises that individuals have knowledge, competences and emotions, and takes into account rules and norms that are collectively applied, and that actors evolve in specific individual material framework (e.g. the home) as well as collective arrangements (e.g. access to waste sorting facilities). Consequently, TSP considers that actions cannot be explained directly by the individual and their cognitive system, or completely by the social rules of the social system in question, as actions also depend on material mechanisms and their use. The main subject of study is therefore no longer the individual or a group of individuals, but the action itself and the practice corresponding to 'a routinized type of behaviour which consists of several elements, interconnected to one other: forms of bodily activities, forms of mental activities, 'things' and their use, a background knowledge in the form of understanding, knowhow, states of emotion and motivational knowledge' [START_REF] Reckwitz | Toward a theory of social practices: A development in culturalist theorising[END_REF]. Consequently, the main object of study shifts from actors (and in particular their deliberate decisions) to practices and their adoption and evolution. This shift in focus allows us to work with a more contextualised understanding of food-related decisions and behaviours [START_REF] Hennchen | Knowing the kitchen: Applying practice theory to issues of food waste in the food service sector[END_REF] and to gain a better understanding of their dynamics.

System of practice elements.

Beyond the ontological positioning of TSP, its originality also lies in its systemic consideration of practices. As such, routines emerge not only from the presence of various elements, but also by their connections made by the actors [START_REF] Spurling | Interventions in practice: Reframing policy approaches to consumer behaviour[END_REF] and the importance they attach to them. More specifically, for [START_REF] Shove | The design of everyday life[END_REF] (following [START_REF] Røpke | Theories of practice -New inspiration for ecological economic studies on consumption[END_REF][START_REF] Hargreaves | Practice-ing behaviour change: Applying social practice theory toproenvironmental behaviour change[END_REF], practices emerge from the interconnection of three types of elements: competences, meanings and the material environment.

Competences cover all the knowledge, skills (physical or cognitive) and know-how to carry out the practice and to function in an appropriate way, in compliance with certain social rules [START_REF] Reckwitz | Toward a theory of social practices: A development in culturalist theorising[END_REF][START_REF] Schatzki | The site of the social: A philosophical account of the constitution of social life and change[END_REF][START_REF]Consumption and theories of practice[END_REF]. This element brings together the different forms of knowledge identified in environmental and social psychology, recognized for their more or less strong influence in changing individual behaviours: theoretical knowledge, procedural knowledge and evaluative knowledge [START_REF] Kaiser | Ecological behavior's dependency on different forms of knowledge[END_REF], to which some authors add a social dimension, involving subjective understandings, with social norms and expectations [START_REF] Redman | Transforming sustainable food and waste behaviors by realigning domains of knowledge in our education system[END_REF]. In this context, theoretical knowledge, which is constructed from the information transmitted, has relatively little influence on behavioural change, unlike procedural and evaluative knowledge [START_REF] Redman | Advancing educational pedagogy for sustainability: developing and implementing programs to transform behaviors[END_REF]. The latter correspond to concrete skills or to knowledge that estimates the effectiveness of actions. For example, knowing the best way for storing food (procedural knowledge) is a prerequisite for limiting waste and cooking to current hygiene standards; knowing that a conventional meal emits an average of 1.35 kg/CO2 eq (carbon dioxide-equivalent) while a steak meal emits 6.3 kg/CO2 eq, and a vegetarian 0.5 kg/CO2 eq1 (evaluative knowledge), provides a 'scale' in the effectiveness of diet choices.

Meanings refer to an individual's mental activities that are associated to a practice. In contrast to competences and material elements, it seems more difficult to reach a consensus on a precise definition of the scope of these mental activities [START_REF] Shove | The design of everyday life[END_REF]. According to the various definitions that have been proposed (and in particular those of [START_REF] Reckwitz | Toward a theory of social practices: A development in culturalist theorising[END_REF][START_REF] Schatzki | The site of the social: A philosophical account of the constitution of social life and change[END_REF]Shove et al., 2012, which are key studies), they would be translated into motivations, goals, projects, beliefs, or emotions and affective states during practice, to finally aggregate into a posteriori meaning [START_REF] Innocent | La valeur pour le consommateur d'une pratique de maîtrise de consommation : le cas de l'électricité[END_REF]. For example, the motivation to purchase soy-based foods may be derived from a desire to reduce meat intake and lower the risk of cardiovascular disease, and justified by having what is perceived to be a lower environmental impact. The meaning associated with the product is therefore ultimately that of a better choice for health and the environment. For the sake of simplification, [START_REF] Shove | The design of everyday life[END_REF] propose to define meanings as 'representations associated with a practice, which give it meaning'. These authors thus establish a link between meanings and social representations. [START_REF] Lahlou | Penser Manger. Les représentations sociales de l'alimentation[END_REF] describes the latter as a structured set of intersubjective cognitive elements that represent the common space of possible representations. Individual mental representations [START_REF] Gallen | The role of mental representations in the choice process, a multidisciplinary approach applied to the case of food products[END_REF] are considered as subsets of this space.

Materiel environment concerns objects, infrastructures, tools, software and the body itself insofar as it enables action [START_REF] Shove | The design of everyday life[END_REF][START_REF] Shove | The design of everyday life[END_REF]. In the case of food practices, this may involve the domestic material environment such as kitchen layout or utensils available, as well as the outdoor material environment such as the different shops to which individuals have access or digital applications enabling them to find specific products, particularly organic, local or packaging-free refillable groceries [START_REF] Innocent | Sustainable food practice: the influence of the physical environment[END_REF]. This interconnection of elements gives properties to the system of practices, including the fact that it can change. This dynamic comes from the evolution of some of these elements and their links. Thus, acquisition of new competences, and changes in material conditions or meanings lead to a change in practice(s). In parallel, through the association and combinations of a variety of these elements, and through their repetition, practices evolve over time [START_REF] Shove | The design of everyday life[END_REF][START_REF] Shove | Conceptualising connections: energy demand, infrastructures and social practices[END_REF][START_REF]Consumption and theories of practice[END_REF]. Practices are therefore to be conceived in a dynamic way, in their evolution and/or potential for evolution [START_REF] Shove | The design of everyday life[END_REF]. Consequently, studying the elements of a system of practices and their interactions helps to understand the implemented practices and their actual or potential dynamics. Figure 1 shows the three elements and their interconnections to represent a sustainable food practice.

Figure 1: The sustainable food (SF) system

Related practices

Carrying out practices also requires the implementation of chains of action that can encompass several aspects of social life [START_REF] Schatzki | Where the action is: On large social phenomena such as sociotechnical regimes[END_REF]. Several daily practices can therefore be linked. This is the case for food consumption, since the purchasing/preparation/storage/eating activities are practices in themselves and combine with one another [START_REF]The practice of eating[END_REF][START_REF] Webb | A re-examination of socially responsible consumption and its measurement[END_REF]. In this sense, what has been called the system of food practices amounts to a set of practices related to the notion of food. [START_REF] Shove | The design of everyday life[END_REF] highlight the importance of focusing on these linked practices, which often have one or more defining elements in common. For example, although buying local and having a vegetable garden to be self-sufficient and grow your own food are two different practices, it seems plausible that both practices are associated with certain common representations in the minds of individuals. Therefore, to understand how several related practices evolve, the network of elements that they share needs to be defined. Furthermore, the idea that meanings, which can be related to representations, could be shared by several related practices, prompts questions about whether a hierarchy exists in related practices. Indeed, it can be hypothesised that a system of several related practices can contain both central and peripheral practices, just as it can central and peripheral representations (Abric, 2014).

Applying TSP to the system of food practices: obstacles to overcome

The literature points to two main obstacles in the general application of the TSP, and its application to the food sector in particular.

The first is scoping the field of practices to be studied. The notion of a system of food practices means that activities never occur in isolation; practices are therefore always embedded in the interconnections of activities, which must be identified to understand the observed phenomenon (Aricia et al., 2021). However, this identification remains difficult and is generally more conceptual than empirical [START_REF] Nicolini | Practice Theory, Work, and Organization. An Introduction[END_REF]. ( 2021), the practice of eating has not been fully understood: eating is a highly personal and social act that is intrinsically linked to many other central processes of daily life [START_REF] Paddock | Invoking simplicity: 'Alternative' food and the reinvention of distinction[END_REF][START_REF]Consumption, food and taste[END_REF].

This systemic and integrative consideration of practices often clashes with the positivist orientation of most research approaches, in which causes and effects can be isolated and controlled, and the (often incremental) changes tracked and counted. However, for [START_REF] Watsona | Challenges and opportunities for re-framing resource use policy with practice theories: The change points approach[END_REF], practice theory may give rise to difficulties in attributing impact, while diffusion of responsibility ideas that emerge from research on social practice study make it more difficult to hold particular organisations to account [START_REF] Evans | Constructing and mobilizing 'the consumer': Responsibility, consumption and the politics of sustainability[END_REF].

This difficulty relates to the second obstacle in the application of TSP, which is a methodological one. The study of practices requires an understanding of the competences and roles of individuals and how they use the material devices at their disposal [START_REF] Plessz | La théorie des pratiques. What contributions for the sociological study of consumption?[END_REF]. Narrative and ethnographic methods are therefore often adopted, but these methods, based on interviews or observations, generally involve a limited number of participants which makes it difficult to generalise the results obtained. Furthermore, questions can be raised about whether it is appropriate to study a practice through discourse (Robert-Desmontrond et al., 2020), whereas practice theory places the practice at the heart of the system, as the individual is only the bearer. Multi-approach studies are still rare, like those of [START_REF] Plessz | How consumption prescriptions affect food practices: Assessing the roles of household resources and life-course events[END_REF] or [START_REF] Dubuisson-Quellier | Consumer devices and dispositions. A review of a contemporary survey articulating qualitative and quantitative methods[END_REF] who combine quantitative data with qualitative study to examine the impact of government directives or market requirements on individuals, rather than simply studying how the recommendations are integrated into food practices.

The limited amount of work and the aforementioned methodological tensions lead to the additional difficulty of obtaining, in a quantitative approach, reliable measures of the different practice elements. For example, in this study we had to make a choice about the measurement of meanings. This was done through consumption values as the link between values and representations is supported by several authors, both in marketing and in sociology [START_REF] Marion | Customer value formation: interactions, uncertainties and framings[END_REF][START_REF] Heinich | Defining value from a sociological perspective[END_REF]. Indeed, for Marion, the notion of values is the observable trace of evaluation processes, and thus reflects the rational, but also emotional, aspects of the subjectobject interaction. As the proposal has recently been extended from objects to practices [START_REF] Innocent | La valeur retirée d'une pratique : une application au cas des économies d'électricité[END_REF], the concept seemed to us to be adaptable.

In summary, the TSP is an appropriate conceptual framework for food research: it reveals the complexity of food practices by focusing not only on three types of elements (competences, meanings and material devices), but above all on their interactions and on the links between the various practices. In a systemic approach, a system can renew itself by modifying its connections. By borrowing from the systemic approach the ability of a system to renew itself by modifying its connections, TSP makes it possible to study the dynamics of food practices and the 'mechanisms' that favour the emergence of specific practices. However, while the elements of a practice and certain roles are regularly identified in studies, the links between these elements and between the related practices are more difficult to analyse. This major limitation is linked to the methodological choices made, particularly the corpus selected and the collection tool used. By using a quantitative approach, the research presented therefore makes it possible to offer a representation of the system of sustainable food practices, as experienced by consumers, while identifying the drivers of an effective sustainable food practice and precisely determining the influence of each factor that leads to the adoption of this practice.

Methodology

A quantitative study was conducted to ascertain the most effective drivers for sustainable food, and to measure the relationships between the elements of a practice.

Data collection and respondents

The data was collected online at the beginning of 20202 from a sample of respondents selected by an access panel company; 501 usable questionnaires were retained3 . The representative nature of the sample, with regard to the French metropolitan population, was ensured by the quota method on five socio-demographic criteria: age, gender, social class, level of education and place of residence (region). There is a slight difference in the representation of certain age groups and education levels compared to the metropolitan population (Appendix 1).

Presentation of measuring instruments

The study focused on four types of variables, with reference to the system presented in Figure 1: actual practices, competences, meanings and the material environment of sustainable food. These were assessed using reliable measurement scales that had been validated by previous studies.

Actual practices were measured by a 28-item practice scale representing 5 dimensions (Divard et al, 2020a).

 First (16 items) dimension: called 'buying and cooking products with sustainable attributes', is characterised by a set of practices with increasing degrees of difficulty in terms of buying local, seasonal products, packaging-free and refillable groceries or items from the deli counter, labelled products (organic, fair trade, sustainable fishing), and certain everyday practices such as home cooking. This dimension is measured using a score from Item Response Theory (IRT) model, and its reliability is ensured using the SepRep separation coefficient4 . A polytomous IRT model5 was used because it can determine the latent trait common to actions that the classical measurement theory approach would have separated into distinct factors (such as purchasing modes and choice of labelled products), while taking into account the probability of respondents carrying out these acts.  Second dimension: anti-waste food preservation practices (5 items).  Third dimension: anti-waste practices in the kitchen (3 items),  Fourth dimension: growing your own food (2 items),  Fifth dimension: consumption of plant proteins (2 items).

These last four dimensions are based on classical measurement theory. It should be noted that the frequency of meat consumption was tested during the creation of this measurement tool. It was unsuccessful since this variable does not seem to be part of any of the latent practice variables identified.

Competences, which are self-assessed, are measured by 15 items representing 4 dimensions:

(1) cooking skills, (2) knowledge of local offer, (3) knowledge of labels, and (4) slightly more technical knowledge about packaging, waste sorting, and seasonal products (Divard et al., 2020b). The measurement tool was previously tested on a convenience sample (n=571) and was refined on this occasion. The items mainly concern procedural knowledge (cooking skills and local offer) and evaluative knowledge (knowledge of the guarantees offered by different labels). A few items concern more theoretical knowledge, such as knowledge about seasonal fruit and vegetables.

Measurement of meanings is carried out through the concept of consumption values, and takes into account benefits and costs or sacrifices associated with sustainable food practice. Several steps were involved in the construction of the measurement tool. First, we adapted a scale from another responsible practice [START_REF] Innocent | La valeur retirée d'une pratique : une application au cas des économies d'électricité[END_REF]. To ensure that the scale covers all of the meanings associated with sustainable consumption, the tool was initially tested on a sample of 528 respondents. This allowed the initial 23 items to be refined; at this stage, the tool was composed of 21 items divided into seven components, one of which dealt with the social dimension of sustainable food. However, this component had low reliability, so it was deleted and some items were reworded following further qualitative pretesting of the scale. An 18-item tool, divided into six theoretical components, was thus administered. Confirmatory factor analyses (CFA) with partial least squares path modelling (PLS-PM) were conducted on these six components. The results led to a simplification of the measurement tool into three factors: two for the valuation of sustainable food and one for its devaluation (i.e. 'costs'). Ultimately, the valuation consists of two components: one relating to the collective objectives of sustainable foodenvironmental and civic actionsand the other to well-being and health-related benefits that more directly affect the individual. Therefore, grouping these items together makes sense from a statistical and theoretical point of view. As the construct is reflexive and the reliability indicators (Cronbach's α and Dillon-Goldstein's Rho) are of very good quality, the total number of items was reduced to 11 for the sake of parsimony.

Material environment was measured using the four spheres of material enablers identified by [START_REF] Innocent | Sustainable food practice: the influence of the physical environment[END_REF]: 'Housing and personal equipment', 'Environment in close proximity', 'Purchase area' and 'Digital environment'. Two to three items were created for each sphere, with a total of 11 items. A system of binary yes/no response modalities was used, as this was not an appreciation-based dimension but a matter of access or possession. The tool was then pre-tested with around twenty people. To study how the material environment of sustainable food is structured, from a statistical perspective, we carried out a multiple correspondence analysis (MCA 6 ) between the various items proposed in the questionnaire. This method makes it possible to study the association between different qualitative variables. The results show a two-factor structure that differentiates between the domestic material environment, mainly associated with housing and individual equipment, and the outdoor environment, which includes purchasing arrangements in particular. The full set of measures is presented in Appendices 2 to 5. The reliability and validity indicators of the different measures are specified in Table 1.

A quantitative interpretative approach

The objective of the research is to explore the links between the main elements of sustainable food practices, without any initial preconceptions about the causal links between these different elements. In this sense, our scientific project is close to the interpretativist hypothesis, according to which human activities are not erratic but present certain regularities (patterns) that are temporarily stable [START_REF] Yanow | Interpretation and method: empirical research methods and the interpretive turn[END_REF]Avenier and Gavard-Perret, 2012). This exploration between the elements of a practice is based on the general framework of theory of social practices (TSP) proposed by [START_REF] Shove | The design of everyday life[END_REF]. TSP thus makes it possible to start from the general hypothesis that there are links between these different elements in the sustainable food practice system, and that these links reflect an 'intersubjective objective reality TSP' through shared meanings [START_REF] Sandberg | How do we justify knowledge produced within interpretive approaches?[END_REF].

Therefore, the only starting position on which our model is based is that the degree of practice depends on the strength of the links between the different practice elements.

To test this model, we used Structural Equation Modelling (SEM). Our approach differs from the classical use of SEMs, which are mainly used in a hypothetico-deductive approach. However, some studies draw attention to the use of quantitative methods in an interpretativist epistemological framework and, more specifically, underline the relevance of quantitative modelling using SEM in this context (Brabet, 1988[START_REF] Galan | A deconstruction of measurement tools in marketing[END_REF][START_REF] Massa | Value, service and sensation in the current music concert experience: an interpretative approach using quantitative and qualitative data[END_REF]. This is a common practice in the ecological sciences, where the discovery of significant statistical relationships in a corpus of data (i.e. 'signatures') often leads to the advancement of theoretical models to the extent that researchers are able to isolate the variables likely to explain a phenomenon [START_REF] Marquet | On theory in ecology[END_REF][START_REF] Servedio | Not just a theory-the utility of mathematical models in evolutionary biology[END_REF][START_REF] Houlahan | The priority of prediction in ecological understanding[END_REF]. These questions are increasingly arising and being debated in the human sciences, where big data and algorithmic processing make it possible to identify statistical patterns in large amounts of various data (behavioural, biological, physiological, etc.), and to make relatively precise predictions [START_REF] Huneman | The profiling societies. Evaluate, Optimize, Predict[END_REF].

The approach consists in the creation of structural sub-models testing certain relationships. These sub-models are analysed and interpreted to feed into the creation of one or more global structural models that correspond to a representation of the phenomenon studied [START_REF] Massa | Value, service and sensation in the current music concert experience: an interpretative approach using quantitative and qualitative data[END_REF]. The aim here is to rigorously explore the various sub-models (Figure 2, M1 to M6) based on the theory of social practices [START_REF] Shove | The design of everyday life[END_REF], with the use of competitive orientation in the statistical links between the latent variables. To test these sub-models, we used EQS (covariance-based SEM) (M1, M3, M5 and M6), and XLSTAT (consistent PLS)7 (M2 and M4) depending on the number of variables involved8 .

The results from each model were then taken into account to create the overall model, which offers a more synthetic representation of the main links in the sustainable food practice system. For this second step, we chose the PLS-PM approach9 (variance-based SEM, XLSTAT software and SmartPLS). This choice is justified by the exploratory purpose of the overall model, and the large number of measured and latent variables of which it is composed [START_REF] Hair | An assessment of the use of partial least squares structural equation modeling in marketing research[END_REF][START_REF] Ringle | Editor's Comments: A Critical Look at the Use of PLS-SEM in "MIS Quarterly[END_REF]. The construction of this model and its testing is presented in the Results section.

Results

Emergence of a general model of the system of sustainable food (SF) practices

In order to create a general model of the SF practice system, the first step was to study the covariance matrix between all the latent variables (5 practices, 4 competences, 3 meanings and 2 material environments -Appendix 6), and then the results of the tests of the 6 sub-models of the relationships between each type of variable taken in pairs (Appendix 7).

In more concrete terms, all models were tested one after the other. Table 2 presents the main findings of these tests and reads as follows: the sub-model tested (first column), main statistical results from testing these models10 (second column), and interpretations and main theoretical lessons derived from them (third column). This is how a general model of the relationships between all elements of the sustainable food practice system gradually emerged (Figure 3).

Table 2. Main findings of the sub-model test

Model concerned

Main statistical results

Interpretations and main theoretical lessons

Covariance matrix All latent variables are related, except for 5 relationships that are not significant. This mainly concerns the link between certain practices (e.g., 'anti-waste storage', and 'grow your own food'), but also the link between the material environment and certain practices.

The structure of the matrix confirms the notion of a system in which not all practices are linked.

Covariance matrix

There is strong covariance between the practices of 'buying and cooking sustainable products', and 'plant proteins'.

The hypothesis made here is that the practice of 'buying and cooking sustainable products' influences the amount of plant proteins introduced into the diet ('plant proteins' practice). This seems logical insofar as composition of the diet is dependent on product choice and purchase.

M1 Links between practices and meanings

The individual benefits explain 'buying and cooking sustainable products', 'growing your own food', 'plant-based proteins' and 'antiwaste cooking' practices, and are in turn explained by the 'buying and cooking sustainable products' and 'growing your own food' practices.

Costs influence 'buying and cooking sustainable products' and 'growing your own food' practices and are influenced by 'buying and cooking sustainable products' and 'anti-waste storage' practices.

There appears to be an interactive meaning-practice relationship for the components of 'individual benefits' and 'cost', particularly for the practice of 'buying and cooking sustainable products': the perceived individual benefits positively influence the practice, which in turn will increase the extent of individual benefits experienced.

Perceived costs reduce the practice, but for 'buying and cooking sustainable products', the costs are reduced.

In the final model, however, we place:  Individual benefits as antecedents to the practices, as they are the 'engine' that can trigger the process [START_REF] Meinherz | Ecological concerns weren't the main reason why I took the bus, that association only came afterwards': on shifts in meanings of everyday mobility[END_REF] and,  Cost undercutting as a consequence of practice [START_REF] Innocent | La valeur retirée d'une pratique : une application au cas des économies d'électricité[END_REF].

M1 Links between practices and meanings

Collective benefits do not influence practices, but they are explained by 'buying and cooking sustainable products' and 'anti-waste storage' practices.

Collective benefits are only a consequence (and not an antecedent) of certain practices. This is in line with the findings of other studies in the transport field (e.g. [START_REF] Meinherz | Ecological concerns weren't the main reason why I took the bus, that association only came afterwards': on shifts in meanings of everyday mobility[END_REF]. A possible explanation is that the collective benefits associated with the environment are distant from individuals and would only become concrete once the practice is established (Van Lange and Huckelba, 2021).

M2 Links between competences and practices

All SF practices are explained by the competences, although 'buying and cooking sustainable products' is the practice that is best explained (R2 = 54%). All four competences are in turn explained by the practices, in a significant and homogeneous way (between 26 and 43%).

The different sustainable food-related competences behave as antecedents and consequences of practices. As the aim is to develop the drivers of sustainable food practices, they are placed as antecedents in the general model [START_REF] Carstensen | Cycling cultures in Northern Europe: from Golden Age to Renaissance[END_REF][START_REF] Eskenazi | Voir, faire et vivre la ville pour le vélo[END_REF].

M2 Links between competences and practices

The model reveals the existence of specific competence-practice 'pairs' according to the following pattern:  Local offer knowledge with 'growing your own food' practice  Technical competence with 'anti-waste storage' practice  Culinary competence with 'anti-waste cooking' practice 'Buying and cooking sustainable products' is the only practice that influences all competences and is, in turn, influenced by all of them (except the technical competence).

Most competences are practice-specific.

However, all of the competences, except the technical ones, influence the 'buying and cooking sustainable products' practice, thus placing it in a specific situation since it is linked to at least two other practices ('growing your own food' and 'anti-waste cooking') through the competences they require.

The 'buying and cooking sustainable products' practice is thus representative of a related practice described by [START_REF] Shove | The design of everyday life[END_REF]. This result gives the 'buying and cooking sustainable products' practice a special and central position in the model.

M3 Links between material environment and practices

The domestic material environment influences several practices (buying and cooking sustainable products, growing your own food, anti-waste cooking) and is in turn influenced by some practices (buying and cooking sustainable products, growing your own food).

The outdoor material environment also influences several practices (buying and cooking sustainable products, anti-waste storage, growing your own food, plant proteins) and is influenced by the practices of buying and cooking sustainable products, growing your own food, and plant proteins.

The relationship between the material environment and practices is interactive. A priming effect is made possible by an enabling material environment (e.g. El [START_REF] Alami | Numerismorphosis and sports activities: the role of connected objects in harmonising practices[END_REF]. Therefore, 'environment' is placed as an antecedent in the general model.

M4 Links between competences and meanings

There are several significant links that work both ways (competences to meanings, and meanings to competences). However, the effects are relatively small.

No dominant causal relationship seems to emerge from this sub-model.

M5 Links between material environment and competences

Material environment, in its two components, influences, to varying degrees, the four competence components, while only the purchasingand product choice-related components (local offer, and label competences) influence the outdoor material environment, whose items are strongly linked to these two activities of purchasing and product choice.

An enabling material environment is a prerequisite for the development of competences. Secondly, specific competences can lead individuals to seek out material solutions in their own environment for sustainable food practices.

Arsel and Bean ( 2013) have furthermore shown that competences act as mediators between the material environment and development of practices. In the general model we will therefore place competences as dependent on the material environment.

M6 Links between meanings and material environment

There are some links between certain meanings and the material environment. However, the explained variability of the latent variables is relatively low.

No dominant causal relationship seems to emerge from this sub-model.

At the end of the analysis of the intermediate models, it emerges that material environment can be placed as a model antecedent. Competences are dependent on this environment and therefore occupy a potentially mediating position between the material environment and practices. We take into account the pairs of competences and practices and the particularity of the 'technical competence' factor to establish the links to be tested. Individual benefits are considered as antecedents of practices, while collective costs and benefits depend on them. Finally, the very strong correlation between 'buying and cooking sustainable products' and the 'consumption of plant proteins' is taken into account by hypothesizing that this first practice influences the second. Finally, Figure 3 represents the general 'testable' model, in a linear version, of the sustainable food practices system, which groups all the links that appeared when testing the previous sub-models.

Figure 3 -General model of the sustainable food practice system

Testing the general model of SF practice

This section focuses on testing the general model of the emerging practice system.

The qualities of the measurement and the structural models are satisfactory. The reliability of the PLS-PM measurements is verified on the basis of a 500 bootstrap procedure [START_REF] Tenenhaus | PLS path modeling[END_REF]. The results are presented in Table 3. Only significant links with an effect size (f2)11 greater than 0.05which corresponds to a 'weak superior' effect [START_REF] Innocent | La valeur pour le consommateur d'une pratique de maîtrise de consommation : le cas de l'électricité[END_REF] were retained.

Discussion

Three main contributions emerge from this research. The first is a proposed categorisation of practices in a system of practices. The second concerns the role of its different elements. The present discussion details these theoretical contributions and then highlights the methodological contributions and questions. The third relates to the implications of these results on food transition, which are addressed in the final concluding section.

The system of sustainable food practices: central and peripheral practices

The results show that the sustainable food system is complex and not homogeneous. Indeed, some sustainable food practices share common elements. However, not all practices and elements are interconnected, and some practices differ from others by how much they interconnect with elements in the system.

The interpretation of these results leads to a categorisation of practices within the system. One of the ways in which this study contributes to the theory of social practices is by proposing a distinct definition of 'core' and 'peripheral' practices in a system, with, in the latter, those which emerge and those which evolve in parallel.

Figure 4 proposes a theoretical translation of the results obtained in diagram format so as to give a clearer view of the sustainable food practice system. It follows the codifications used in the theory of social practices (notably the use of double arrows to link elements, see [START_REF] Shove | The design of everyday life[END_REF]).

Figure 4 -The system of sustainable food practicesconnections and shared elements Central practices: numerous connections to the elements in the system 'Core practices' can be defined as practices that share and are connected, within the system, with many competences, meanings and material elements. Referring to the 'central core' or 'structuring core' concept of a social representation (Abric, 2014), the central practice could have an organising function of the sustainable food system and also would appear to have a positive influence on other practices. In the system of sustainable food practices, 'buying and cooking sustainable products' is a practice that holds this central position since it has a direct influence on the consumption of plant proteins, and an indirect one through increasing technical competences, and storage and anti-waste conservation measures. The virtuous circle of sustainable food practices would therefore be based on this foundation composed of a central practice that would allow the emergence or reinforcement of complementary peripheral practices. The composition of this foundation would reflect the consumers' main representations of a more sustainable diet and make it possible to highlight both the drivers and gaps in collective representations and realities with respect to transition [START_REF] Coley | Food miles: time for a re-think?[END_REF].

The large number of items involved in the latent variable of 'buying and cooking sustainable products' may nevertheless raise questions about a statistical focal effect that would lead to it being artificially assigned the position of central practice. However, the number of items involved in this variable remains consistent with the scientific practice observed in this field (Thogersen et al. in 2010 used a score from an array of 17 items in the field of energy practices). Conversely, the question may arise as to whether there are sufficient items in the other practices to describe them in all their diversity. The tool to measure practices was constructed in such a manner that items reflecting actions that did not fit with any others, such as the frequency of consumption of meat productsa choice that is based on the very definition of practices, which are constellations of actions [START_REF] Schatzki | Social practices: A Wittgensteinian approach to human activity and the social[END_REF].

Peripheral practices: emerging or evolving in parallel

We define peripheral practices as those which share few links with the constituent elements of the system. In our model, the practices of supply by growing your own food and anti-waste storage are considered to be peripheral as they only share the following with the system: domestic material environment for the former, and technical competences for the latter. Antiwaste cooking seems to be isolated within the system as culinary skills do not seem to be linked to any other practice.

Peripheral practices are sometimes emergingsuch as the consumption of plant-based proteins or evolving in parallel (i.e. not closely associated with other sustainable practices)such as anti-waste practices or growing your own food. Being able to distinguish between peripheral practices and central practices and identify the missing links should lead to a better targeting of the actions to be taken. In our case study, the emerging practice of consuming plant proteins is strongly correlated with the practice of buying and cooking sustainable products. What these two practices have in common is that they are influenced by the same (individual) benefits, the same culinary competences, and knowledge about the label.

In the context of practices that are already established but evolve in parallel, links need to be created via the practice elements. Our results show that, at this stage and in the case of sustainable food, competences play a central mediating role. This is not always the case; other elements can play this mediating role such as meanings (see [START_REF] Shove | The design of everyday life[END_REF] and the example of the car).

To try and answer the initial research questions of this study, the entry point via the central practice of sustainable food, that is the practice of buying and cooking sustainable products, seems to be the central driver. However, it can be seen that the system is strongly determined by its elements, which play several roles.

Elements of practice: a connecting and a strengthening role

The first insight revealed by the research on practice elements is the fundamental role played by material elements and competences. It is a role that applies to both the stabilisation and evolution of practicesalready reflected by theory and proven by numerous research studies and the mediating character of these to 'connect' practices to each other, which is predicted by the theory but less frequently proven. Although the importance of a facilitating material environment has already been shown [START_REF] Innocent | Sustainable food practice: the influence of the physical environment[END_REF] in the field of sustainable food, the driver of competences, procedural knowledge in particular, is probably still underactivated.

A second insight revealed is that different meanings do not play the same role in the practice: individual benefits mainly appear as practice antecedents, while collective benefits and cost minimisation appear as practice consequences. The valorization of individual benefits can therefore be an entry point for encouraging sustainable food practices. Once the latter have been proven, arguments highlighting the practice's collective benefits and lower costs can lead to the reinforcement of behaviours. These individual and collective benefits are very close to the egocentric and altruistic benefits set out by Achabou and Dekhili (2021) about sustainable consumption and its specificities in the luxury sector. Collective benefits, however, include altruistic benefits that are oriented towards the common, human good, and biospheric benefits (Séré de Lanauze, 2015).

The private/public nature of the practice could also explain the difference in the role given to elements of meaning about the practice. There is a difference between domestic ecological behaviours carried out in the home, and visible behaviours that generate social interactions and can be seen by others (e.g. buying products directly from the producer) [START_REF] Schmitt | Unpacking the relationships between pro-environmental behavior, life satisfaction, and perceived ecological threat[END_REF]. Visible behaviours would bring more life satisfaction through the dual mechanism of social validation and decreased eco-anxiety [START_REF] Masson | We need climate change mitigation and climate change mitigation needs the 'We': a state-of-the-art review of social identity effects motivating climate change action[END_REF][START_REF] Schwartz | Climate change anxiety and mental health: Environmental activism as buffer[END_REF]. Thus, the increase in collective benefits and the decrease in costs observed mainly through implementing the 'buying and cooking sustainable products' practice, would partly come from the fact that a part of these actions take place in the public space.

Measuring the practice system: methodological contributions and issues

Beyond the limitations inherent in any quantitative study, (such as a slight representativeness bias), this approach raises some questions and difficulties. Some are theoretical and relate to the 'meanings' and 'material environment' elements of the practice, whereas others are related to the implementation and concern the measurement of competences and practices.

Contributions and questions on the 'meanings' and 'material environment' constructs

To reliably measure the meanings of practices, several options are available: we can turn to the different concepts from the field of sociology, such as social representations (Abric, 2014;[START_REF] Croizean | Segmenting markets from social representations: the case of food products[END_REF][START_REF] Lahlou | Penser Manger. Les représentations sociales de l'alimentation[END_REF], or from marketing sciences, such as value [START_REF] Innocent | La valeur retirée d'une pratique : une application au cas des économies d'électricité[END_REF]. Our research offers an example of such implementation. However, the definition of the concept of meanings in the theory of practices remains and is itself a point for reflection for future research.

The material environment element raises further questions. While theoretically based on objective and factual elements, it seems more likely that this factor is partly fixed and partly perceived. For example, there may be digital tools (website, apps, etc.), or accessible sales outlets available, however, if individuals do not go looking for them they could easily imagine that they do not exist. The material reality for a consumer would then be composed of two factors: the material environment available and the material environment perceived to be available. This aspect adds an element of complexity, whose impact on the results of the present study is difficult to assess.

Contributions and challenges of measuring competences and practices

At the same time, it is more complicated to reliably measure the competences and practices carried out. In the case of practices and with a view to proposing a stable and reliable tool, it was necessary to use two measurement theories: item response theory and classical measurement theory. Indeed, practices are either a homogeneous whole that can be described in terms of a limited number of items (frequency of consumption of certain food groups for the consumption of plant proteins, for example), or a combination of uncoordinated actions that contribute to the same objective. Thus, home cooking, buying local, seasonal and labelled products are all different actions that pursue a common objective: a better diet for the environment and for health. These structural differences have consequences on the measurement theories that can be applied to them. As for competences, the difficulties involved in measuring them partially overlap with those of practices because there can be various levels of knowledge homogeneity in a given domain. Furthermore, competences, as we have measured them, are self-evaluated; however, just because a person thinks they have mastered anti-waste cooking techniques, does not necessarily mean that they have done so.

This work shows the importance of improving techniques and furthering the work already carried out on measuring the descriptive constructs of consumer's actual practices and their competences.

Conclusion and implications for speeding up transition

There are three levels of recommendations that can be made on the basis of this work. We need to promote the formation of links within the practice system by building on the core practice, more specific actions should also address emerging practices, and, finally, our results strongly support the idea that it is necessary, as soon as possible, to move from so-called awareness-raising actions to actions that increase competence in order to support responsible transformations.

Building on central practice

The central practice 'buying and cooking sustainable products', seems to be the main driver for strengthening the entire system and thus for speeding up the spread of sustainable food practices.

However, within this very practice, some of the actions are questionable with regard to the objective of food transition, which is to reduce the environmental footprint of our food. In this way, consumers directly associate buying local with sustainable food, whereas for several years ADEME (2017) has been showing that buying local has a limited impact on the reduction of greenhouse gas emissions. At the same time, while the majority of prospective studies on lowcarbon diets highlight the importance of introducing more plant-based foods into the diet [START_REF] Solagro | Afterres 2050, an agricultural and food transition scenario[END_REF]LiveWell3, 2017), this behaviour does not yet seem to be integrated by consumers as a central element of a sustainable food practice.

Future support programmes should therefore focus on creating virtuous circles to reinforce the entire system of the practice and also engage in a process aimed at qualifying certain representations. We could thus envisage campaigns built around an idea of sustainable eating which means choosing products with a low environmental impact, reducing packaging at source, avoiding waste by preserving and cooking intelligently, eating plant-based and alternative proteins and, whenever possible, growing your own vegetables.

Supporting the emergence of peripheral practices

Putting in place specific support to encourage emerging practices is the second driver for speeding up change.

Applied to the substitution of animal proteins with plant or alternative proteins (entomophagy for example), it is probably easier to start consuming new products based on these new proteins (peripheral practice in the system), than to reduce meat consumption (isolated action, not integrated in the system). This is in line with the findings of [START_REF] Verplanken | Good intentions, bad habits, and effects of forming implementation intentions on healthy eating[END_REF]; for these authors it is easier to introduce a new habit (via specific intentions to implement new actions) than to discontinue an old one. In other words, this is a matter of working towards cultural change through novelty rather than restriction.

However, further work on flexitarian practices seems necessary to gain a better understanding of this aspect of sustainable food practices.

Exploiting the connection function of competences: moving from to competence development

The study results show that competences are a key element of the system of sustainable food practices as they play a mediating role between different practices. Consequently, the third driver towards more sustainable food is to increase consumer competence in food sustainability issues. This involves moving away from an awareness-raising message to actions that enable consumers to acquire new knowledge which can then be used to measure the impact of their actions (evaluative knowledge) and new know-how to increase their power to act (procedural knowledge). Boosts illustrate this possibility, but are different from nudges in that these programmes play a part in competences and not in behaviour directly, and their effect is considered to be more sustainable over time [START_REF] Hertwig | Nudging and boosting: Steering or empowering good decisions[END_REF]. Their potential as tools for behavioural change, and thus for speeding up transitions, may be due to their capacity for connecting competences.

Programmes such as cooking workshops for developing competences in home-cooking and raw ingredients can thus promote the practice of 'buying and cooking sustainable products'. These programmes, however, should emphasise plant-based and alternative protein cooking competences as well as food waste reduction in order to activate the entire system of practices.

More indirect competences also need to be developed, based on aspirations for greater naturalness and transparency (Allès et al., 2017). Behind this lies the consumer's need for security, but also the desire to reconnect with nature, which requires a more sensitive and embodied understanding of the natural food production cycle [START_REF] Sachse | Les jardins partagés, terreau de participation citoyenne : de l'appropriation de l'espace public à la construction de commun(s) Regards croisés entre la France et l'Italie[END_REF]. This reconnection with nature [START_REF] Otto | The prosocial origin of sustainable behavior: A case study in the ecological domain[END_REF] contributes to developing the eater's competence through improved understanding of how food is produced and its production constraints.

Extending the research

This study examined the system of sustainable food practices of French consumers. The quantitative and interpretative approach used here could be applied to other systems of practices, such as soft mobilities or the Three Rs (reuse, repair, recycle). It could also be applied to other cultural food contexts. Firstly, this would increase the external validity of the approach proposed here, and secondly it would highlight any differences in the relative influence of the different elements of the system of practices and whether they are central or peripheral.

Finally, a study with a longitudinal approach could be conducted to highlight the real evolution of the system of practices. The continuation of this research would make it possible to evaluate the impact of each element of the system as the development of sustainable food practices progresses and as each of its elements evolve. It could also highlight the diverse pathways of engagement in sustainable food practices.

Figure 2 -

 2 Figure 2 -The six sub-models of the sustainable food (SF) practice system

Table 1 .

 1 Reliability indicators of the measurement tools

	Indicators

Measuring benefits and costs associated with sustainable food practices

	Collective benefits	Environmental and civic benefits of sustainable food	3	0.88	0.57
		practices.
	Individual benefits	Individual health and well-being benefits associated with	4	0.91	0.62
		sustainable food practices.
	Costs	Costs of changing habits, organisation, purchase locations,	4	0.89	0.55
		time and information associated with sustainable food
		practices.
	Measuring sustainable food practices using the material environment score
	Material	Material environment: Domestic: owning a garden,	5
	environment:	waste separation equipment, etc.
	Domestic
				NC (not concerned)
	Material	Material environment: Outdoor: accessible sales outlets	6
	environment:	and digital localization platforms, containers for the
	Outdoor	purchasing of packaging-free refillable groceries.

Table 3 -

 3 Results of the general model

		Dependent variables	Significant links
	Model Adjustment	Var	R²	Var	Factor score	f2
	Measurement model:	Competence:	0.20 Material environment:	0.25 (t=6.079)	0.07
	variables ρ D.G ⋝ 0.8 • One-dimensional latent confidence interval zero absent from the • Parameters all significant:	Local offer		offer Outdoor > Competence: Local Material environment: Local offer Domestic > Competence:	0.34 (t=8.289)	0.14
	• Convergent and discriminant validity -AVE ⋝ 0.5 and AVE	Label Competence:	Outdoor > Competence: Label 0.15 Material environment:	0.31 (t=7.255)	0.11
	> squared correlations
	• HTMT ratios < 0.85 (Henseler	Competence:	0.23 Practice: Buying and cooking	0.36 (t=7.916)	0.13
	et al., 2015)	Technical		sustainable products >
	• Average of communalities:			Competence: Technical
	0.64	Practice:	0.62 Competence: Local offer >	0.30 (t=8.414)	0.14
	Structural model: • Predictive quality: Q2 > 0 • Relative GoF: 0.96	Buying and products sustainable cooking		Practice: Buying and cooking Buying and cooking Competence: Label > Practice: sustainable products	0.24 (t=6.992) 0.26 (t=7.444)	0.10 0.11
	except for the 'Culinary'			sustainable products
	competence, and the practices			Individual benefits > Practice:
	of anti-waste storage, growing			Buying and cooking
	your own food, and anti-waste			sustainable products
	cooking; Q2 EC1 = 0.57	Practice: Anti-	0.11 Competence: Technical >	0.33 (t=7.678)	0.12
		waste storage		Practice: Anti-waste storage
		Practice:	0.23 Material environment:	0.45 (t=10.815) 0.24
		Growing your		Domestic > Practice: Growing
		own food		your own food
		Practice: Plant	0.21 Practice: Buying and cooking	0.32 (t=5.428)	0.06
		proteins		sustainable products >
				Practice: Plant proteins
		Practice: Anti-	0.20 Competence: Culinary >	0.42 (t=9.376)	0.18
		waste cooking		Practice: Anti-waste cooking
		Collective	0.30 Practice: Buying and cooking	0.50 (t=12.920) 0.34
		benefits		sustainable products >
				Collective benefits
		Costs	0.18 Practice: Buying and cooking	-0.43 (t=-10.51) 0.22
				sustainable products > Costs

Measuring sustainable food practices Wording, parameters and thresholds of the items for the practice of 'buying and cooking sustainable products'

  You buy fresh produce from local producers (collective farmers' shop, farmers' market, open-air market, farm shop, etc.) .You buy longer life or non-perishable products (frozen meat, tinned food, preserves, etc.) from local producers or food artisans.

		Items	Location	T1	T2	T3	T4
	You can prepare 'home-cooked' meals using minimally-or non-processed ingredients (vegetables, cereals, legumes, meat, fish, etc.).		-0.89	-2.31	-1.46	-0.90	1.12
	You prefer locally produced fruit and vegetables.		-0.15	-1.05	-1.30	-0.26	2.02
	You reuse food packaging if suitable to do so (glass jars, bottles, plastic packaging) rather than throwing it away.		-0.09	-0.78	-1.03	0.43	1.01
	You choose food products with limited packaging.		0.10	-1.59	-0.84	0.74	2.10
	You buy food products (meat, cheese, etc.) from the deli counter.		0.19	-0.97	-0.80	0.32	2.21
	You prefer healthy and energy-efficient cooking methods (braising, pressure cooker).		0.20	-1.48	-0.68	0.56	2.41
	You adapt your purchases according to what is offered by local producers.		0.51	-0.29	-0.42	0.63	2.13
	Vocational qualification (CAP, BEP) You ensure that the seafood you buy is sustainably sourced.		0.52	24 -0.14	-0.07	24 0.53	1.76
	No qualification or highest qualification BEPC, brevet des collèges or DNB You buy organic or similar fruit and vegetables. 0.55	22* -0.68	-0.24	31 0.88	2.22
	Socio-	Self-employed person (Agri., trader, company	0.75	3 -0.43	-0.27	4 1.07	2.62
	professional	manager...)
	categories You buy certain categories of products (coffee, tea, chocolate, etc.) Senior manager, liberal professions with a fair trade label.		0.83	8 -0.27	-0.06	9 1.15	2.48
	Middle-level occupations You buy packaging-free refillable groceries (excluding fruit and vegetables) .		0.87	10* -0.26	-0.11	14 1.14	2.71
	Employee or Worker You buy store cupboard essentials (flour, pasta, spices, etc.) that are organic or similar.		0.93	31 -0.21	-0.08	29 1.27	2.72
		Retiree			25		27
				1.12	-0.06	0.27	1.28	2.97
		Other: inactive persons			23*		16
	Region You buy meat that is organic or similar. Paris Region		1.14	16 0.18	0.35	19 1.44	2.58
	UDA9
	North You buy organic products from local producers.		1.37	10* 0.08	0.33	6 1.65	3.41
	T = threshold.	East			7		8
		Paris Basin East			8		8
		Paris Basin West			8		9
		West			14		14
		South West			12		11
		Central East			12		12
		Mediterranean			12		13

* Difference in proportion is significant at the 0.05% threshold.

Appendix 2:

Wording and parameters of items for the practice of Anti-waste storage

  You look at the expiry dates of perishable products at the time of purchase.You put products with the shortest expiry date at the front of the shelf in the fridge to use them first.You make sure you use the recommended storage method for the different types of perishable products (e.g. keeping vegetables that spoil rapidly at the correct temperature) .

			Standard	Critical
	Items	Correlations	error	ratio
		0.43	0.09	4.88
	You look at the expiry dates of products already in the fridge.	0.76	0.05	16.23
		0.68	0.06	11.93
	You check that products stored in the cupboards are still edible.	0.69	0.06	11.91
		0.78	0.05	16.95
	Response modalities: Never; Rarely; Occasionally; Often; Always/Systematically; Not concerned or impossible
	Wording

and parameters of items for the practice of growing your own food

  You can use garden-grown food, from your own garden or that of neighbours, family, friends, etc.

			Standard	Critical
	Items	Correlations	error	ratio
	You use the produce from your or a shared garden.	0.89	0.03	35.66
		0.90	0.02	39.24

Response Modalities: Never; Rarely; Sometimes; Often; Mostly; Not concerned or impossible Wording

and parameters of items for the practice of Plant proteins

  How often do you consume a portion of plant-based protein products (e.g., soyabased/almond-based etc. drinks, desserts or cakes).

			Standard	Critical
	Items	Correlations	error	ratio
		0.75	0.05	13.90
	How often do you consume a portion of dried vegetables (dried beans, lentils, peas, soya beans, etc.) .	0.86	0.03	25.65
	Response Modalities: Never; Once a week or less; Twice a week; 3 to 5 times a week; Once a day (6 to 7 times a week); Twice
	a day
	Wording

and parameters of items for the practice of Anti-waste cooking

  When you prepare food in large quantities, you store (freeze, refrigerate) the surplus for days when you don't have the time to cook or don't feel like cooking.

	Annex 3:
			Standar	Critical
	Items	Correlations	d error	ratio
		0.66	0.07	10.17
	You sometimes prepare 'improvised' meals according to what you find in your fridge and cupboards.	0.69	0.06	11.10
	You cook the leftovers.	0.86	0.03	34.24
	Response Modalities: Never; Rarely; Occasionally; Often; Always/Systematically; Not concerned or impossible

Measuring competences associated with sustainable food

  You know the opening days/times of the different sales outlets for local products in your area (collective farmers' shop, farmers' market, open-air market, farm shop, etc.).You know what types of recycling are accepted by your local council (e.g. type of plastic, yoghurt pots, etc.).

	Material Environment > Meanings Chi² (DoF): 391.68 (60)	Individual benefits	0.15	Material Env: Domestic > Individual benefits		0.25
	CFI: 0.82 RMSEA: 0.105 (0.095-0.115)	Items	Costs	0.11	Correlations Material Env: Domestic > Costs	Standard error	Critical ratio -0.21
			Competence: Culinary Material Env: Outdoor >
					Collective benefits		0.30
	You know how to prepare 'home cooked' meals from raw products.		0.775	0.030	25.725
					Material Env: Outdoor >
	You know recipes that can be made from fresh, seasonal vegetables.	0.836 Individual benefits	0.017	49.076 0.26
	You know how to cook legumes (lentils, dried beans, chickpeas, etc.).	0.756 Material Env: Outdoor > Costs	0.027	28.059 -0.22
	You know how to cook an 'improvised' meal from ingredients you have at	0.751	0.031	24.384
	home.
	You know how to use leftovers.					0.716	0.030	23.494
			Competence: Local offer
	You know where to find local producers in your area.			0.887	0.010	87.982
	You know which products are available from local producers in your area.	0.867	0.014	62.907
						0.838	0.017	50.594
	You know where to find local products in your usual shops.			0.693	0.035	19.834
			Competence: Labels
	You know the guarantees offered by the organic labels.			0.889	0.016	57.015
	You know the guarantees offered by fair trade labels.			0.933	0.009	103.303
	You know the guarantees offered by sustainable fishing labels.			0.909	0.010	91.927
			Competence: Technical
	You can identify seasonal fruit and vegetables.			0.780	0.025	31.739
	You can recognise products that have recyclable packaging.			0.705	0.038	18.644
						0.667	0.038	17.728
	Response Modalities: Strongly disagree; Somewhat disagree; Neither agree nor disagree; Somewhat agree; Strongly agree

Source: Base Carbone © de l'ADEME: https://bilans-ges.ademe.fr/

Also, before the first COVID-19 lockdown in France.

These questionnaires corresponded to the quality conditions we had set, i.e. a response time equal to or greater than 8 minutes (time considered necessary for answering correctly), and no repetitive responses to the item scales.

SepRel (separation reliability) is comparable to Cronbach's alpha[START_REF] Petrillo | Using classical test theory, item response theory, and Rasch measurement theory to evaluate patient-reported outcome measures: a comparison of worked examples[END_REF].

In the present study, we used a model with 5 response modalities on the frequency of carrying out the proposed actions (from never/rarely/often to always/all the time). For some questions, we proposed a 'not concerned' modality to limit the social desirability bias. These responses were recoded in the 'never' modality.

Multiple Correspondence Analysis (MCA) is to qualitative variables what Principal Component Analysis (PCA) is to quantitative variables. It is mainly used to produce visual representation maps of the similarities between the categories of qualitative variables and observations[START_REF] Jolibert | Marketing Research: methods of research and studies in marketing 1st edition[END_REF].

The consistent PLS (or PLSc) method is an alternative solution for testing models that involves reflexive latent variables and for which the covariance-based SEM approach cannot be applied[START_REF] Cheah | Assessing reflective models in marketing research: A comparison between pls and plsc estimates[END_REF].

We used covariance-based SEM (EQS) software to test these sub-models as every model involves only a moderate number of latent variables. However, some models involving sustainable food competences did not converge (M2 and M4). This is probably due to the large number of measured variables (15). In these two cases, the sub-models were tested with XLSTAT in consistent PLS.

Partial Least Squares (PLS) Path Modelling.

All of the covariances, fit indices and significant relationships for each model can be found in Annexes 6 and 7.

The f2 corresponds to the relative influence of the variable through its participation in the R 2 . Values of 0.35, 0.15 and 0.02 of the f2 correspond respectively to strong, moderate or weak effects[START_REF] Hair | An assessment of the use of partial least squares structural equation modeling in marketing research[END_REF].

Acknowledgements

The authors sincerely thank the editor, guest editors and anonymous readers of RAM for their guidance, comments and suggestions which greatly helped to improve the quality of this

Appendices Appendix 1: Representativeness of the sample in relation to the French population

There are community, shared or allotment gardens where I live.

I can use my bike or go on foot to do my main food shop.

I can do my main food shop by stopping off during a regular journey (work, school, etc.).

There are places selling local/organic/packaging-free refillable groceries near where I live.

I have access to websites or apps showing places selling food (producers, packaging-free refillable grocery shops, etc.) near where I live.

Appendix 6: Analysis of covariances between latent variables