Background: Literature has shown a tendency of inadequate dietary intake among youth, consequently, nutritional interventions are required. The transtheoretical model (TTM) classifies individuals based on their readiness to change. This model is widely used for health education interventions with proven efficacy. Purpose: This review aimed to weigh the strength of evidence about the TTM usage in nutritional interventions for adolescents and its effectiveness regarding dietary intake. Methods: This study followed the PRISMA guidelines. Eligible studies were input into Mendeley software. The Adolec, Google Scholar, LILACS, PsycINFO, PubMed, Science Direct and Web of Science databases were searched. Only full original articles written in English, Spanish or Portuguese on randomized controlled trials and quasi-experimental designs that applied the TTM in the design of nutritional interventions targeting adolescents were included, with no restrictions on publication date. The quality and risk of bias was evaluated with the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies. Results: The initial search yielded 3779 results. Three studies were rated as strong, six as moderate and five as weak. The final sample of 14 articles included adolescents that were mostly recruited from schools, with interventions ranging from one month to three years. The TTM was used alone or combined with other behavior-change theories and most of the interventions involved digital technology. The nutritional topics covered included fruit and vegetable consumption, low-fat diet, and cooking skills. Four studies presented improvement in fruit and vegetable consumption and four progressed through stages of change. Participants from two interventions reduced fat intake. At the end of one intervention, all the participants were in action and maintenance stages. Conclusion: The TTM seems to be a successful strategy for nutritional intervention aiming at improving dietary intake in adolescents. Its application in different contexts shows that the TTM is flexible and possible to be implemented in many settings. The use of the model is shown to be restricted to the stage of change’ construct. Further studies should use all constructs of the TTM in the design and compare the TTM with other behavior-change theories to better understand its effectiveness.

OBJETIVO: Avaliar o desempenho e a percepção de cinco modelos de rotulagem nutricional frontal (RNF) entre consumidores brasileiros. MÉTODOS: Estudo transversal, com aplicação de questionário online a 2.400 indivíduos, alocados de forma aleatória em seis grupos de estudo, sendo um controle e cinco expostos a modelos de RNF (octógono, triângulo, círculo, lupa e semáforo), aplicados a nove alimentos. Foi avaliado o entendimento do conteúdo nutricional, a percepção de saudabilidade, a intenção de compra e a percepção dos consumidores brasileiros sobre os modelos. RESULTADOS: Todos os modelos de RNF aumentaram o entendimento do conteúdo nutricional e reduziram a percepção de saudabilidade e a intenção de compra, quando comparados ao grupo controle (41,3%). Os modelos de RNF de advertência - octógono (62,4%), triângulo (61,9%) e círculo (61,8%) - apresentaram desempenho significativamente superior ao semáforo (55,0%) quanto ao entendimento do conteúdo nutricional. O desempenho do modelo da lupa (59,5%) não diferiu dos outros quatro modelos testados, inclusive do semáforo (55,0%), para o entendimento do conteúdo nutricional. A análise individual dos alimentos sugere melhor desempenho das advertências em relação à lupa e ao semáforo para a percepção de saudabilidade e a intenção de compra. Os consumidores manifestam-se favoráveis à presença da RNF, percebendo-a como confiável para aumentar o entendimento das informações nutricionais. CONCLUSÃO: A RNF deve ser implementada nos rótulos dos alimentos no Brasil, considerando que aumenta o entendimento nutricional, reduz a percepção de saudabilidade e a intenção de compra de alimentos com nutrientes críticos. As advertências apresentaram melhor desempenho quando comparadas aos demais modelos.

This study aimed to evaluate the effect of a nutritional intervention involving a problem-raising approach and the use of pictorial representations on the promotion of knowledge and practices of healthy eating among adolescents. This randomized study included 461 adolescents from public schools in Brasilia, Federal District, Brazil (intervention group: 273 students from four schools; control group: 188 students from three schools). Mean age was 14.8±1.0, and 52.9% were boys. The intervention consisted of three meetings with interactive activities about principles of healthy eating, food classification, importance of reading labels and analyzing food advertising critically, and representations of healthy and unhealthy meals and their sugar, salt, and fat content. Pictorial materials consisted of food drawings, food models, and a food packaging model. Controls were not exposed to any activity. Dietary knowledge, consumption, and behaviors were the variables of interest. The intervention group showed a higher mean score of correct answers to questions about dietary knowledge than the control group (p = 0.0006), with higher odds of correctly answering questions about in natura (OR: 3.7; 95% CI: 1.9–6.6), minimally processed (OR: 3.6; 95% CI: 1.9–6.4), processed (OR: 2.2; 95% CI: 1.1–4.3), and ultra-processed foods (OR: 3.5; 95% CI: 1.8–6.6) and composition of ultra-processed foods (OR: 2.4; 95% CI: 1.3–4.4). Participants in the intervention group were also 2.5 times more likely to correctly answer questions about the importance of the dietary environment (95% CI: 1.1–5.5) and caution with food advertising (95% CI: 1.2–5.3) than controls. Increased weekly consumption of vegetables (p = 0.0077; OR: 2.4; 95% CI: 1.26–4.51) and reduced consumption of soft drinks (p = 0.0212; OR: 0.36; 95% CI: 0.15–0.86) were observed in the intervention group compared to the control group. The proposed intervention increased adolescents’ knowledge and improved some of their dietary habits. Educational activities using a problem-raising approach and pictorial representations of food appear to be effective in promoting healthy eating practices among adolescents.

Purpose.To assess the impact of a six-month stage-based intervention on fruit and vegetable intake, regarding perceived benefits and barriers, and self-efficacy among adolescents.Design.Randomized treatment-control, pre-post design.Subjects/Setting.Schools were randomized between control and experimental groups. 860 adolescents from ten public schools in Brasília, Federal District, Brazil were evaluated at baseline; 771 (81%) completed the study.Intervention.Experimental group received monthly magazines and newsletters aimed at promotion of healthy eating.Measures.Self-reported fruit and vegetable intake, stages of change, self-efficacy and decisional balance scores were evaluated at baseline and post-intervention in both groups.Analysis.The effectiveness of the intervention was evaluated using the analysis of covariance model (ANCOVA) and repeated measurement analysis by means of weighted least squares. Comparison between the proportions of adolescents who advanced through the stages during the intervention was performed using the Mantel-Haenszel chi-square test.Results.After adjusting for sex and age, study variables showed no modifications through the proposed intervention. There was no statistical difference in participant mobility in the intervention and control groups between the stages of change, throughout the study.Conclusion.A nutritional intervention based exclusively on distribution of stage-matched printed educational materials was insufficient to change adolescents’ dietary behavior.

Objective: This study aimed at reviewing food-based dietary guidelines (FBDGs) with content targeted at children and adolescents to present their main characteristics, thus enabling comparisons among countries.Design: We conducted a search of the FBDGs available on the Food and Agriculture Organization (FAO) website, followed by a scoping review with a gray literature search to find FBDGs for children or adolescents non-listed on the FAO's website. Data extraction included the year of publication, language, and guidelines for the target group.Results: From FAO website searches, 109 documents were found, and 17 of them could not be translated. The Scoping review search conducted in 5,190 articles, and none led to new guidelines, nor from the gray literature. Regarding the 92 FBDGs explored, 41 were specific for infants under 24 months old, children, and/or adolescents, and 51 were for the general population with information for the studied group. Twelve percent of the general FBDG and 35% of the specific ones have food icons. All of the guidelines were published after 2001. Latin America and the Caribbean were the regions that presented more specific FBDGs and the majority of countries with guidelines for fruits and vegetables. The information about fat (15 countries) and sugar (26 countries) consumption reduction is frequent. Reduction of sodium intake appears to be in the majority of guidelines after 2015. Food hygiene guidelines are recurrent in Latin American documents. NOVA classification was adopted in five countries and 21 countries approach recommendations for mealtimes. Both exclusive and continued breastfeeding guidance and healthy complementary feeding orientation are present in over 50% of the specific FBDG for infants and children under 24 months old.Conclusion: Food-based dietary guidelines are diverse due to both the nutritional and political aspects of each region. Latin America stands out for its orientations for the studied group. Further studies should measure the possible impacts and comprehension of FBDGs.

Several food and nutrition education actions have been described in the literature, with emphasis on the recommended use of innovative methods when addressing a young audience. Digital games are an attractive, dynamic, and motivating resource for teaching and learning practices, and adolescents form the group that readily accepts and adopts new technologies. Adapting dietary and nutritional guidelines to change dietary behavior is a challenge, and game-based learning has several benefits that can be used in this sense. Thus, this study aims to outline a nutritional intervention for school-aged adolescents from the Federal District, Brazil, whose object is a digital card game aimed at promoting healthy dietary practices. In this randomized study with intervention and control groups, we propose a nutritional intervention for adolescents studying in Federal District private schools. The intervention group will be introduced to Rango Cards, a digital game specifically developed for this study. The purpose of the game is to present the concept of an adequate and healthy diet using simple information in a playful context. This game features cards for foods/meals, characters, and healthy habits. The players’ choices may lead them to winning or losing. Theme selection and phase order were designed to provide a learning experience. The control group will not receive any material during the study. Both groups will complete questionnaires before and after the intervention. The game is expected to improve food knowledge and self-efficacy in the adoption of healthy practices, thus contributing to appropriate dietary consumption. The game was designed as a food and nutrition education tool based on Brazilian dietary guidelines. We believe that Rango Cards will provide a comprehensive experience on the topic, improving the students’ autonomy, motivation, and pleasure of learning. RBR-72zvxv June 29, 2018; Retrospectively registered.