A proposal for food and nutrition education integrated into the preschool and elementary school curriculum Proposta de educação alimentar e nutricional integrada ao currículo de Educação Infantil e Ensino Fundamental Propuesta de educación alimentaria y nutricional integrada en el currículo de Educación Infantil y Enseñanza Fundamental

Materials were prepared for schoolteachers and healthcare workers to support permanent initiatives in food and nutrition education in schools, integrated into the curriculum. The article presents the matrix of food and nutrition topics that served as the basis for producing these materials (Matrix) and the convergence between the approach adopted in the activities in the Activity Manuals comprising the series of materials and food dimensions, the principles of the Framework for Food and Nutrition Education for Public Policies (Framework for Food and Nutrition Education), and the Brazilian National Curriculum Guidelines for basic education. The Matrix allowed designing educational activities that foster an expanded approach to food and nutrition which is simultaneously crosscutting and integrated into the curriculum. The activities allowed dialogue with various components of the curriculum and linkage between them. The activities’ convergence with the Framework for Food and Nutrition Education was expressed in the contextualization of food practices in the schoolchildren’s territories and realities; in the problematical approach, which encourages critical thinking and the promotion of autonomy, both for educators and schoolchildren; and inter-sector planning through topics and action strategies that encourage collaboration between healthcare professionals and teachers. The initiative presented in this article thus strengthens the actions by food and nutrition education in schools and can expand teachers’ repertoire in food and nutrition and contribute to its crosscutting and routine inclusion in the curriculum. Feeding Behavior; School Health Services; Teaching Materials Correspondence L. Maldonado Universidade do Estado do Rio de Janeiro. Rua São Francisco Xavier 524, Rio de Janeiro, RJ 20550-900, Brasil. luamaldonado71@gmail.com 1 Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brasil. This article is published in Open Access under the Creative Commons Attribution license, which allows use, distribution, and reproduction in any medium, without restrictions, as long as the original work is correctly cited. Maldonado L et al. 2 Cad. Saúde Pública 2021; 37 Sup 1:e00152320 Introduction The search to guarantee health and food as basic human and civil rights, with an emphasis on the promotion of adequate and healthy food, has stimulated the formulation and implementation of public policies. In Brazil, the Brazilian National Food and Nutrition Policy 1 is a milestone in this commitment and has backed the development of strategies and actions, including the following: the elaboration of dietary guidelines 2,3, programs 4, orientation for the organization of services, and promotion of adequate and healthy food in various spaces 5. In several of these actions as well as other initiatives, food and nutrition education has been valued as a fundamental strategy for the promotion of adequate and healthy food, and schools have been identified as a prime space for health promotion, due to their potential for developing critical thinking and autonomy among all school community members 6,7,8. Historically, the health sector’s work in schools has been based on different conceptions and strategies, varying from informative and normative actions centered on the individual and focused on students’ behavior change to pedagogical practices consistent with the principles of health promotion, promoting critical thinking and autonomy. Importantly, these two forms of practices coexist in the actions performed today in Brazilian schools and are influenced by the conceptions of education and health that serve as the basis for the actions 9,10. Health at School Program (PSE) is the result of partnership between the health and education sectors. One of its purposes is the development of health education activities in schools 11. The PSE provides an opportunity for the development of activities in the promotion of adequate and healthy food. However, one of the main challenges for the promotion of adequate and healthy food in schools is to break with the interventionist perspective 7 based on fragmented and isolated activities with no connection to the school curriculum. In addition to the PSE, action in food and nutrition education has been promoted by various policies and strategies in school. For example, Law n. 11,947/2009 12 values activities in food and nutrition education in school, recommending their linkage with the school’s pedagogical proposal. Various actors have been identified for the development of such practices, including teachers, kitchen and dining hall staff, schoolchildren, nutritionists in the Brazilian National School Feeding Program (PNAE), and health workers from the primary healthcare teams 4,11,12,13. Aimed at supporting approaches to food and nutrition in the PSE, a series of support materials was produced for schoolteachers and healthcare workers for use in the school community. The initiative resulted from a partnership between the Institute of Nutrition, Rio de Janeiro State University (UERJ), the General-Coordination of Food and Nutrition (CGAN) of the Brazilian Ministry of Health, and the Pan American Health Organization (PAHO). The current article aims to present the Matrix of topics in food and nutrition in food dimensions according to the educational segment (Matrix), which served as the basis for producing these materials, besides presenting the convergence of the approach taken in the activities in the Activity Manuals (hereinafter Manuals) comprising the series of materials with the food dimensions, the principles in the Framework for Food and Nutrition Education for Public Policies 6 (Food and Nutrition Education Framework), and Brazilian national curriculum guidelines (DCN) for basic education. Theoretical framework The exclusively biological approach to food fails to incorporate other dimensions that are necessary for developing adequate responses to contemporary food issues. An expanded conception includes not only nutritional and health aspects (the biological dimension) but also the view of food as a universal human right that should be guaranteed along with other rights to ensure respect for a decent and full life, since such rights are indivisible, interrelated, and interdependent (the dimension of the human right to adequate food); symbolic and affective aspects of food and eating in their relationship to people and society (socio-psychocultural dimension); work relations and other issues that involve the sectors of production and distribution of foods in their dynamics with the economic market (economic dimension); in addition to the impact and environmental sustainability of the food systems’ production, supply, and marketing processes (environmental dimension) 14,15. FOOD AND NUTRITION EDUCATION INTEGRATED TO SCHOOL CURRICULUM 3 Cad. Saúde Pública 2021; 37 Sup 1:e00152320 Thus, teaching practices and activities in food and nutrition education should consider the theme’s crosscutting and dialogical nature, as well as subjective aspects related to food and eating. The history of public policies in Brazil shows that the 1990s marked a turning point in food and nutrition education as a strategy for the promotion of healthy eating practices, attuned with the new milestones in health promotion and health education, in line with critical, comprehensive, and emancipatory practices and moving away from initiatives aimed simply at disseminating information and behavior change 6,16. A key feature of this turning point was the elaboration of the Framework for Food and Nutrition Education 6, which involved different government sectors and institutions working in food and nutrition in Brazil. This aim was to support public policies in food and nutrition education as a powerful strategy for the promotion of adequate and healthy food, based on a broad concept and innovative principles for the framework’s implementation. The Framework for Food and Nutrition Education became a basic reference for reflection and orientation on practices in food and nutrition education, highlighting its transdisciplinary, inter-sector, and interprofessional nature and its integration in the context of people’s lives. For these purposes, the Framework points to the need for innovative, problematizing, and active pedagogical approaches 6. Food and nutrition topics have many interfaces with other health topics already incorporated into the school curriculum and with various contents in all the curricular components. The development of actions linked to the curriculum aims to expand the understanding of this theme and correlate the school curriculum content with the multiplicity of factors associated with food practices. Brazil’s National Law on Guidelines and Foundations for Education 17 and National Common Curriculum 18, which orient the curricula in the country’s overall educational system and pedagogical proposals for the school systems, underline the commitment to a comprehensive formative experience that considers individuals in the learning process in terms of their singularity, integrity, diversity, and otherness, aimed at overall human development. By implementing food and nutrition education, schools contribute to building knowledge and developing a critical approach to food, a structuring practice for social relations. These characteristics favor the promotion of adequate and healthy food in schools, based on the recognition of food as a human right. Methodological approach The elaboration of the series of materials in 2014 and 2015 included the stages we describe next. First, we conducted a search of Brazilian Ministry of Education documents in force at that time supporting the organization of curricula for preschool and elementary school (the latter defined for the purposes of this article as K-9, or primary school plus junior high) 19,20,21,22,23,24,25 and on the contents related to food and nutrition in textbooks aimed at the 5th to 9th grade of elementary school. Next, a workshop was held to identify windows of opportunity in the curriculum to work on food and nutrition topics. This activity helped identify demands for approaches to the promotion of adequate and healthy food in schools. It included representatives of the public health and education systems from various states, representing all five major geographic regions of Brazil, members of the CGAN and PAHO, and three pedagogical experts, one of whom specialized in preschool and the other in elementary school, who followed the entire project. The result of this workshop was the construction of a chart by school segments (preschool, early elementary, and late elementary) with the following data: opportunities in the curriculum (contents according to curricular components), themes/contents in food and nutrition, possible teaching strategies, and suggested reading. These products were further improved using the literature search mentioned above, performed by the authors, with the support of the pedagogical experts. The result of this process is systematized in Boxes 1 and 2. Maldonado L et al. 4 Cad. Saúde Pública 2021; 37 Sup 1:e00152320 Box 1 Preschool curriculum contents in dialogue with food dimensions. Rio de Janeiro, Brazil, 2014. WORK DIMENSIONS/AGE GROUP (YEARS) CURRICULUM COMPONENT Personal and social formative process


Introduction
The search to guarantee health and food as basic human and civil rights, with an emphasis on the promotion of adequate and healthy food, has stimulated the formulation and implementation of public policies. In Brazil, the Brazilian National Food and Nutrition Policy 1 is a milestone in this commitment and has backed the development of strategies and actions, including the following: the elaboration of dietary guidelines 2,3 , programs 4 , orientation for the organization of services, and promotion of adequate and healthy food in various spaces 5 . In several of these actions as well as other initiatives, food and nutrition education has been valued as a fundamental strategy for the promotion of adequate and healthy food, and schools have been identified as a prime space for health promotion, due to their potential for developing critical thinking and autonomy among all school community members 6,7,8 .
Historically, the health sector's work in schools has been based on different conceptions and strategies, varying from informative and normative actions centered on the individual and focused on students' behavior change to pedagogical practices consistent with the principles of health promotion, promoting critical thinking and autonomy. Importantly, these two forms of practices coexist in the actions performed today in Brazilian schools and are influenced by the conceptions of education and health that serve as the basis for the actions 9,10 .
Health at School Program (PSE) is the result of partnership between the health and education sectors. One of its purposes is the development of health education activities in schools 11 . The PSE provides an opportunity for the development of activities in the promotion of adequate and healthy food. However, one of the main challenges for the promotion of adequate and healthy food in schools is to break with the interventionist perspective 7 based on fragmented and isolated activities with no connection to the school curriculum.
In addition to the PSE, action in food and nutrition education has been promoted by various policies and strategies in school. For example, Law n. 11,947/2009 12 values activities in food and nutrition education in school, recommending their linkage with the school's pedagogical proposal. Various actors have been identified for the development of such practices, including teachers, kitchen and dining hall staff, schoolchildren, nutritionists in the Brazilian National School Feeding Program (PNAE), and health workers from the primary healthcare teams 4,11,12,13 .
Aimed at supporting approaches to food and nutrition in the PSE, a series of support materials was produced for schoolteachers and healthcare workers for use in the school community. The initiative resulted from a partnership between the Institute of Nutrition, Rio de Janeiro State University (UERJ), the General-Coordination of Food and Nutrition (CGAN) of the Brazilian Ministry of Health, and the Pan American Health Organization (PAHO). The current article aims to present the Matrix of topics in food and nutrition in food dimensions according to the educational segment (Matrix), which served as the basis for producing these materials, besides presenting the convergence of the approach taken in the activities in the Activity Manuals (hereinafter Manuals) comprising the series of materials with the food dimensions, the principles in the Framework for Food and Nutrition Education for Public Policies 6 (Food and Nutrition Education Framework), and Brazilian national curriculum guidelines (DCN) for basic education.

Theoretical framework
The exclusively biological approach to food fails to incorporate other dimensions that are necessary for developing adequate responses to contemporary food issues. An expanded conception includes not only nutritional and health aspects (the biological dimension) but also the view of food as a universal human right that should be guaranteed along with other rights to ensure respect for a decent and full life, since such rights are indivisible, interrelated, and interdependent (the dimension of the human right to adequate food); symbolic and affective aspects of food and eating in their relationship to people and society (socio-psychocultural dimension); work relations and other issues that involve the sectors of production and distribution of foods in their dynamics with the economic market (economic dimension); in addition to the impact and environmental sustainability of the food systems' production, supply, and marketing processes (environmental dimension) 14 Thus, teaching practices and activities in food and nutrition education should consider the theme's crosscutting and dialogical nature, as well as subjective aspects related to food and eating. The history of public policies in Brazil shows that the 1990s marked a turning point in food and nutrition education as a strategy for the promotion of healthy eating practices, attuned with the new milestones in health promotion and health education, in line with critical, comprehensive, and emancipatory practices and moving away from initiatives aimed simply at disseminating information and behavior change 6,16 .
A key feature of this turning point was the elaboration of the Framework for Food and Nutrition Education 6 , which involved different government sectors and institutions working in food and nutrition in Brazil. This aim was to support public policies in food and nutrition education as a powerful strategy for the promotion of adequate and healthy food, based on a broad concept and innovative principles for the framework's implementation. The Framework for Food and Nutrition Education became a basic reference for reflection and orientation on practices in food and nutrition education, highlighting its transdisciplinary, inter-sector, and interprofessional nature and its integration in the context of people's lives. For these purposes, the Framework points to the need for innovative, problematizing, and active pedagogical approaches 6 .
Food and nutrition topics have many interfaces with other health topics already incorporated into the school curriculum and with various contents in all the curricular components. The development of actions linked to the curriculum aims to expand the understanding of this theme and correlate the school curriculum content with the multiplicity of factors associated with food practices.
Brazil's National Law on Guidelines and Foundations for Education 17 and National Common Curriculum 18 , which orient the curricula in the country's overall educational system and pedagogical proposals for the school systems, underline the commitment to a comprehensive formative experience that considers individuals in the learning process in terms of their singularity, integrity, diversity, and otherness, aimed at overall human development. By implementing food and nutrition education, schools contribute to building knowledge and developing a critical approach to food, a structuring practice for social relations. These characteristics favor the promotion of adequate and healthy food in schools, based on the recognition of food as a human right.

Methodological approach
The elaboration of the series of materials in 2014 and 2015 included the stages we describe next. First, we conducted a search of Brazilian Ministry of Education documents in force at that time supporting the organization of curricula for preschool and elementary school (the latter defined for the purposes of this article as K-9, or primary school plus junior high) 19,20,21,22,23,24,25 and on the contents related to food and nutrition in textbooks aimed at the 5th to 9th grade of elementary school. Next, a workshop was held to identify windows of opportunity in the curriculum to work on food and nutrition topics. This activity helped identify demands for approaches to the promotion of adequate and healthy food in schools. It included representatives of the public health and education systems from various states, representing all five major geographic regions of Brazil, members of the CGAN and PAHO, and three pedagogical experts, one of whom specialized in preschool and the other in elementary school, who followed the entire project.
The result of this workshop was the construction of a chart by school segments (preschool, early elementary, and late elementary) with the following data: opportunities in the curriculum (contents according to curricular components), themes/contents in food and nutrition, possible teaching strategies, and suggested reading. These products were further improved using the literature search mentioned above, performed by the authors, with the support of the pedagogical experts. The result of this process is systematized in Boxes 1 and 2.

Box 1
Preschool curriculum contents in dialogue with food dimensions. Rio de Janeiro, Brazil, 2014.

WORK DIMENSIONS/AGE GROUP (YEARS) CURRICULUM COMPONENT
Personal and social formative process   Source: prepared by the authors (2020).
After concluding the first version of the activities to produce the educational materials, a new workshop was held with participation by educators and researchers in food and nutrition education and professionals from the public healthcare system (nutritionists, physicians, nurses, and psychologists) and the school system (teachers and pedagogical coordinators from preschool to late elementary school). They were asked to give their opinions on the adequacy of the activities' language and content, as well as the activities' potential to foster dialogue between health and education. This new workshop's outputs backed the final stage, which included: conclusion of the elaboration of activities, the design and production of videos to support the Manuals, and the production of a booklet on promotion of adequate and healthy food in daycare centers, for health and education adminis-Cad. Saúde Pública 2021; 37 Sup 1:e00152320 trators. Box 3 describes the set of materials in this series. Both the dialogue with partners and the process of developing the materials featured the commitment to the feasibility of implementing the suggested activities.
Boxes 1 and 2 served as the basis for producing the Matrix of themes in food and nutrition according to food dimensions and school segments (preschool and elementary). The content will be discussed in the article's Results and Discussion section. This production was based on a reflexive process conducted by the authors on the intersections between central aspects of the food dimensions and contents planned in the school curriculum. The Matrix was used to orient the approach to food and nutrition in all the materials comprising the series, having oriented the work by the participants in the second expert workshop. After conducting the activities, we returned to the Matrix to be certain that all the themes in food and nutrition had been covered.

MATERIAL DESCRIPTION
Activities Manual for the Promotion of Adequate and Healthy Food:

Box 3
Materials produced for the promotion of adequate and healthy food in the Health at School Program. Rio de Janeiro, Brazil, 2019.
Cad. Saúde Pública 2021; 37 Sup 1:e00152320 To meet this article's first objective, we present the Matrix together with reflections on the expanded perspective of food that it adopts and its potential for organizing a crosscutting approach to food and nutrition from preschool through elementary school.
To meet the second objective, the contents, approaches, teaching strategies, and objectives of the activities in the Manuals were compared to the food dimensions, the DCN, and the principles in the Framework for Food and Nutrition Education. Given the principles' central importance for improving teaching practices, the latter comparison was complemented by systematizing the number of proposed activities per principle in the Framework for Food and Nutrition Education and with examples of how each principle was approached.
Details of these comparisons are provided in two supplementary materials: the first discusses the activities proposed in the Manuals (Supplementary Material. Box S1. http://cadernos.ensp.fiocruz. br/static//arquivo/suppl-e00152320-s1_6178.pdf), their objectives, and interfaces with the food dimensions, curriculum components, and the principles of the Framework for Food and Nutrition Education; the second presents an exercise for linking the themes of food and nutrition to the contents and curriculum components identified in the first workshop and/or adopted in the Manuals according to food dimension and school segment (Supplementary Material. Box S2. http://cadernos. ensp.fiocruz.br/static//arquivo/suppl-e00152320-s2_9233.pdf).

Food dimensions in the Matrix and Manuals
Box 4 shows the Matrix of food and nutrition themes by food dimension and school segment.
The first point for reflection is the expanded approach to food and nutrition in schools provided by the Matrix. Analyses of school textbooks and Food and Nutrition Education practices in schools suggest that this theme is often presented to the school community with a focus on nutritional and health aspects, thereby reducing food and nutrition to their biological dimension 26,27,28 . The adoption of food dimensions as the theoretical reference allowed a dialogue with curriculum components that were previously lacking or treated superficially, as in History and Geography. The food dimensions favored the contextualization of eating practices in the territories and over the course of historical processes related to changes and persistence in different life contexts.
The attempt was also to approach the biological dimension of food in such a way as to overcome the idealized and/or medicalizing view of food and the focus on the prevention and treatment of diseases 29 . The process was also intended to acknowledge the link between this dimension and the others: in the proposed activities, based on the principles of the Dietary Guidelines for the Brazilian Population and the NOVA classification of foods, the nutritional and health aspects were problematized, considering the impacts of food choices on health, culture, and the environment 2,30 . The pedagogical approaches based on this classification have proven more effective than the traditional approaches 31 .
This expanded focus can also be seen in the contents proposed by the Matrix and developed in the activities, featuring the following: the human right to adequate and healthy food 32 , breastfeeding 3 , and the food system 33 in the three school segments; care for the body 18 , and cooking 34 in preschool; food classification according to the extent and purpose of processing 2 , regional foods 35 , and commensality 36 in the early years of elementary school; and food sovereignty 37 , body image 38 , contemporary aspects of food, especially gender issues 39 and consumerism 40 in the final years of elementary school (Supplementary Material. Box S1. http://cadernos.ensp.fiocruz.br/static//arquivo/ suppl-e00152320-s1_6178.pdf; Supplementary Material. Box S2. http://cadernos.ensp.fiocruz.br/ static//arquivo/suppl-e00152320-s2_9233.pdf).
The second point for reflection is the Matrix as organizer of a crosscutting approach to food and nutrition over the course of the school segments. This is expressed in a gradient of complexification in the way a given theme is treated both in the Matrix and in the proposed activities, allowing more in-depth discussion according to the child's development and the curriculum's organization. For example, the human right to adequate and healthy food 32 is explored as one of children's rights, along with playing and studying in preschool; as the concept of human rights in the early elementary school; and as a right to be guaranteed by the State in late elementary school. The food system 33 is discussed in preschool via the professions related to it; the identification of its main components (food chain, food systems, and food practices) in early elementary school; and the discussion on work relations established in this system in late elementary school (Box 4). This crosscutting approach provided by the Matrix and materialized in the activities proposed in the Manuals favors concepts and practices in the promotion of adequate and healthy food that are sensitive to the curriculum and linked to it 12  In general, all the food and nutrition topics provided in the Matrix were addressed, with varying degrees of emphasis. These topics can be the activity's main contents; they can be present in aspects to be discussed in greater depth according to each group of students; or they can also be included in the suggested educational materials for supporting the activities' development.

Activities in the Manuals and curriculum components
The activities allowed a dialogue with various curriculum components (Supplementary Material. Box S1. http://cadernos.ensp.fiocruz.br/static//arquivo/suppl-e00152320-s1_6178.pdf). For preschool, the components in the dimensions "personal and social formative process" and "nature and society" were addressed in the set of proposed activities; and all those in elementary school were covered in each of the two segments, except for physical education in early elementary school.
The activities' conception also favored links between different curriculum components, allowing a comprehensive approach to the knowledge 18 . In early elementary school, the activities included two to six components (in most cases three or four). In late elementary school, they included three to five components (mostly three). This effort at dialogue with the curriculum components and interlinkage is a major practical step forward in food and nutrition education.
In preschool, orality, psychomotricity, and knowledge of oneself and others are characteristics of childhood development that display intense dialogue with food practices, considering the child as a historical subject with rights that builds his or her identity, the structuring dimensions of pedagogical practices and interactions and playing. In this phase, educating and caring are concepts associated with the educational process, and experiences in school, family, and community are the basis for learning socialization, autonomy, and communication 18 . Thus, the central characteristics of the activities in the preschool Manuals are playfulness, stimulus for autonomy and self-care, and the family's involvement.
Elementary school (defined here as primary plus junior high) covers the first nine years of school life in the Brazilian educational system and includes the transition from preschool to early elementary, the change from generalist teachers to specialist (subject-by-subject) teachers, and the transition to late elementary (equivalent of junior high). Over the course of early elementary school, the pedagogical practices that began in preschool are consolidated, organizing the literacy process. Playfulness is still present, interactions with the world are expanded, and logical reasoning is developed progressively. In a dynamic process between the child and the collectives in which he or she participates, autonomy is developed along with the use of multiple languages for the construction and expression of new forms of knowledge 18 . The activities proposed in the Manual for early elementary school are based on logical reasoning and stimulus for the development of orality, maintaining the playful aspects and drawing on social uses of writing and math to build knowledge on food and nutrition. The activities provide opportunities to exercise observation, perception, analysis, representation, and discoveries and are adapted to different needs and capacities for mobilization of cognitive operations.
The transition to late elementary school occurs in a continuous process of expansion of pedagogical practices mediated by relations between individuals and nature, history, technology, and the environment. This is a period of greater cognitive complexity, specialization in areas of knowledge, and critical interaction with different sources of information. Abstract reasoning and the capacity to situate oneself in the other´s place contribute to strengthening autonomy and the development of moral and ethical values. This transition accompanies the passage from childhood to adolescence; thus, to understand the different ways of entering adolescence and expressing the multiple forms of youth is essential for proposing contextualized and dialogical activities 18 . The Manual for late elementary school proposes activities that value this age group's characteristic critical sense and prioritize argumentative capacity as a way of contributing to citizens' participation in society, such as the debate on the relationship between poverty and hunger and the promotion of adequate and healthy food. The activities propose different forms of expression and research using information and communication technologies, seeking to contribute to dialogue between the contemporary world's immediatism and the need for the students' deeper reflections on food and nutrition issues.
In elementary school, organization of the curriculum by components (i.e., subjects) in the areas of knowledge (language, math, natural sciences, and human sciences) becomes more challenging for Cad. Saúde Pública 2021; 37 Sup 1:e00152320 an approach to food and nutrition that promotes linkage between these components. For example, in the activity Cooking, Yesterday and Today, the dialogue with the curriculum components occurred as follows: with the Portuguese language, to stimulate written comparisons between characteristics of the student's food and that of older family members; with History, exploring changes and permanence in eating habits and practices over time; with Math, building charts for a quantitative summary of the collected information; with Geography, identifying foods consumed in the students´ territories; with Science, in the discussion of healthy eating habits; and with Arts, through the possibility of customizing the proposed charts and ways of expressing the systematization of the collected information.
In most cases, the content proposed in the DCN for each segment was used as the basis for developing the activity. For example, "personal, family, and social identity" and "valuing local culture" provided the basis for activities that link to the Portuguese language component (e.g.: Learning About Our Eating Practices) and Geography (e.g.: Our Land's Flavors) in early elementary school. In late elementary school, the contents "self-esteem and diversity" and "identities and beauty" provided the basis for the activities linking History, Geography, Portuguese, Science, and Phys Ed (e.g.: "Body Image I: Collective Identity and Diversity and Body Image II: Individual Identity and Sself-Esteem).

Activities in the Manuals and the principles in the Framework for Food and Nutrition Education
The Matrix and the set of proposed activities converge with all the principles of the Framework for Food and Nutrition Education, which assume specific shapes in the approach to each of the school segments as a function of the child's development and the organization of the school's routine (Box 4 and Supplementary Material. Box S1. http://cadernos.ensp.fiocruz.br/static//arquivo/ suppl-e00152320-s1_6178.pdf). This convergence was expressed in the contextualization of eating practices in the territories and the schoolchildren's realities; in the problematizing approach, which encourages critical thinking and promotion of autonomy for both teachers and schoolchildren; and in the inter-sector planning through themes and action strategies, encouraging collaboration between healthcare professionals and teachers.
Box 5 presents a systematization of the number of activities proposed in the Manuals that address each principle in the Framework for Food and Nutrition Education and illustrate the way the principle was approached in activities in each school segment.
The principles most often approached in preschool are the promotion of self-care and autonomy (principle V) and active and informed participation (principle VI). The activities value the child´s relationship to his or her body, exploring the foods' sensory characteristics, and the perception of relations between food and social practices. These aspects favor learning in general, building the child's positive relationship to food, and the formation of healthy eating habits.
The activities in early elementary school feature the principles of valuing local food culture and respect for different kinds of knowledge (principle III), food as a reference in valuing cooking as an emancipatory practice (principle IV), and promotion of self-care and autonomy (principle V). Dialogue with these principles allows recognition of the plurality of food practices in the Brazilian people's different cultures, since the proposed activities' focus is on food, on the understanding that food is part of daily life, and on the reflections on food practices throughout life. Besides this dialogue, there was also a frequent link to the principles of social, environmental, and economic sustainability (principle I) and the comprehensive approach to the food system (principle II) through linkage with the food system's components, exploring the territory in which the students live, and identification of the actors involved in the production and marketing of foods.
The activities in late elementary school feature the principles of social, environmental, and economic sustainability (principle I), valuing local food culture and respect for different kinds of knowledge (principle III), and promotion of self-care and autonomy (principle V). Their linkage is established through discussions on food in the contemporary context and food systems. Reflection and debate on such issues as commensality, globalization, cooking, food and gender, food choices, consumption, and sustainability, advertising and food labeling, and other components of the food system allow establishing a critical vision of contemporary food and nutrition. for execution of the actions, emphasizing local diagnosis. In many cases it also involves the students in this phase, thus strengthening the participatory approach recommended by the Framework for Food and Nutrition Education.

Box 5
Number and examples of activities according to the principles in the Framework for Food and Nutrition Education for Public Policies (Framework for Food and Nutrition Education), by school segment. Rio de Janeiro, Brazil, 2020.
The principle of education as both a permanent process generating autonomy and individuals´ active and informed participation is present in all the activities in the three school segments. This occurs through proposals of elements for the continuous and integrated incorporation of food and nutrition education in the areas of knowledge and the promotion of autonomous and healthy eating practices. This principle also materializes in the problematizing approach drawing on underlying Cad. Saúde Pública 2021; 37 Sup 1:e00152320 questions in the dialogue with schoolchildren, seeking to explore the different forms of knowledge. This approach implements in practice the perspective that food and nutrition education should prioritize active processes, incorporate real-world knowledges and practices, and contextualize individuals' realities 16 . This happens through dialogical activities, with proposals that encourage critical reflection and understanding of the individual's relationship to the world. The reflection becomes clearer for individuals when the point of departure is situations they experience 41 , such as valuing each family's food diversity, for example in the backyard vegetable gardens; analysis of labels on snacks that children bring to school; a survey of foods that enter their homes, etc. Valuing playfulness and the use of artistic expressions (modeling clay, cut-and-paste, music, painting, games, etc.) are examples of strategies for children's active participation.
Each proposed activity focuses on at least two principles in the approach and may even include all of them. As a reflexive exercise on the translation of the framework's principles to the activities, we will analyze each one's approach in the activity. The School in the Open-air Market, proposed for early elementary school, approaches all the principles as follows: valuing the open-air food market or "farmers' market" as a space for purchasing natural and minimally processed foods and in the dialogue between food production, supply, marketing, and distribution (principles I and II); the focus on preservation of food culture with research on typical regional foods (III); discussion of natural foods as a reference for valuing typical dishes from the child's region and that are based on these foods (IV); reflexive dialogue on the reasons students have never tried some foods (V); further development of the visit with a proposal for conversation with the market vendors and/or farmers (VI); visit to the open-air market (VII); and conversation with farmers (VIII). Meanwhile, principle IX is expressed in the detailed planning in "prior organization" and in the evaluation made by the class itself with a collective drawing that records their experience.
The Manuals favor joint planning between health and education by proposing action strategies that encourage collaboration between these two sectors. The proposed activities are intended to extend beyond traditional approaches in health and education that often fail to make sense for the individuals' lives 42 . Although the materials produced here have a national scope, the activities allow the incorporation of different realities in the schoolchildren's life context and the organization of the school curriculum. These two perspectives are consistent with the "planning" component of principle IX of the Framework for Food and Nutrition Education since they contribute to the definition of common objectives between health and education in the sphere of the PSE and strategies to reach them, which are essential elements for more effective and sustainable practice in food and nutrition education.
In relation to the methodological experience, during the process of elaboration and publication of these materials, DCN were updated due to the curricular reorganization that incorporated daycare centers and preschool into basic education and defined elementary school as nine years of schooling. Especially in preschool, interaction and playfulness were valued and further developed as experiences in these updates, to safeguard the right and need to play and the school's role with families to strengthen small children's autonomy. The changes were in the sense of upgrading the previous guidelines 18 , and the Manuals' content and approach thus remained convergent with the new guidelines.
Another aspect that should be mentioned is that due to the deadlines for delivering the series of materials, it was not possible to pretest all the activities. However, they were mostly built according to activities already tested in various experiences with undergraduate Nutrition students and in practice by healthcare professionals and teachers. To address this limitation, a study is being designed to assess the materials' use. Planning is also underway for the activities in dissemination of the materials. These will involve online forums with state and municipal administrators of the PSE and other strategic actors working the healthcare and school systems that can disseminate and encourage the materials' use.
A key strength of the study was the involvement of pedagogical experts with experience in teaching practice in all three school segments, which allowed consistence and depth in linking the materials and activities to the curriculum.
Cad. Saúde Pública 2021; 37 Sup 1:e00152320 The challenge of producing a single set of materials for all of Brazil provided a daring opportunity. The strategy for reaching this goal was to adopt a process for production of the materials that involved participation by actors from different states of Brazil, representing all five major geographic regions of the country and an approach to the materials that encourages their adaptation to local realities and the discussions raised by the students as the point of departure for the activities.

Final remarks
The Matrix and Manuals contribute to the incorporation of the theme of food and nutrition in schools through actions in food and nutrition education that link the different food dimensions to the contents of the curriculum components in each school segment based on the principles in the Framework for Food and Nutrition Education. It is hoped that this proposal will help overcome the approach to food and nutrition that is limited to the components of Sciences and Biology, to expand educators' repertoire on the theme of food and nutrition, and to include the materials and activities in the school curriculum on a daily and crosscutting basis.
The Matrix had been conceived as a strategy to organize the thinking and work process, but by the end of the elaboration of the materials it had become a theoretical expression of this knowledgebuilding with the potential to orient the production of other materials 43 and projects and practices in food and nutrition education in schools. In addition to the materials produced here, the article's reflexive exercise contributes to the debate on food and nutrition education in the curriculum and to the support for materializing this linkage.
By assuming an expanded understanding of food, we were able to produce a sufficient range of activities to allow dialogue with different curriculum components and to present a series of possibilities for joint action between educators (both schoolteachers and healthcare professionals) and the school community. The proposed activities are anchored in and encourage the autonomy of these educators, since the materials' versatility allow their adaptation to the curricular organization in each school system and to the local contexts. The initiative presented in this article thereby strengthens the actions in food and nutrition education in the school environment and supports the relationship between health and education, a basic element in PSE.