Health literacy among adolescents is critical for empowering them to make informed decisions about their health, encompassing not only knowledge of health topics but also the ability to effectively analyze and apply this information in various contexts (Koca and Arkan, 2020; Sørensen et al., 2012). This skill set directly impacts their health behaviors, such as dietary choices and physical activity, which are crucial during the developmental phase of adolescence (Schulenkorf et al., 2022; Cavicchiolo et al., 2022; Tsubakita et al., 2020; Guo et al., 2018).

Research has shown that health literacy among adolescents is linked to various health outcomes, such as medication adherence, mental health, and obesity (Ramos et al., 2023; Malloy-Weir et al., 2016; Murphy et al., 2010). Low levels of health literacy have been associated with negative health behaviors, poorer health status, and an increased risk of overweight and obesity (Guo et al., 2020). Health literacy plays a significant role in promoting positive health behaviors and empowering adolescents to take control of their health (Taba et al., 2022; Mallia et al., 2020; Awofeso et al., 2017).

Food literacy, which includes nutrition knowledge, food label interpretation skills, and cooking abilities, is a crucial aspect of adolescent health and wellbeing. Studies have highlighted that higher levels of food literacy significantly influence adolescents’ food choices and eating behaviors, leading to increased consumption of fruits and vegetables and reduced intake of fast food and processed snacks (Murad et al., 2021; Koca and Arkan, 2020; Vaitkeviciute et al., 2014).

Interventions aimed at enhancing food literacy among adolescents have shown promising results in improving dietary intake and overall health. School-based culinary programs and nutrition education initiatives have successfully increased adolescents’ food skills, nutrition knowledge, and cooking confidence, leading to healthier eating patterns (Labbé et al., 2023; Ruiz et al., 2021; LeRouge et al., 2019). Social media literacy programs have proven effective in reducing risk factors for eating disorders among adolescents, particularly by addressing body dissatisfaction and disordered eating behaviors (Muth et al., 2022; Agam-Bitton et al., 2018; McLean et al., 2017).

The link between health literacy and dietary behaviors in adolescents is well-documented, with higher levels of health literacy being associated with better preventive and healthy eating behaviors (Sarhan et al., 2022; Bektaş et al., 2021). Adolescents with higher health literacy are more aware of unhealthy foods and more likely to develop healthier eating habits. Also, parental health literacy has been correlated with adolescent health behaviors, highlighting the crucial role of parental involvement and support in promoting healthy eating habits among adolescents (Champion et al., 2023).

Adolescents’ eating habits are critical to their health and wellbeing as this life stage is marked by increased nutritional needs due to rapid growth and development (Yoshida-Montezuma et al., 2020). Poor dietary choices during adolescence can lead to serious health issues such as obesity, glucose intolerance, high blood pressure, and dyslipidemia (Kim and Lim, 2019).

Nutritional education and targeted interventions have proven effective in improving adolescents’ eating behaviors and nutrition knowledge (Bektaş et al., 2021; Qutteina et al., 2021; Raikar et al., 2020; Wang et al., 2015). Equipping adolescents with the information and skills necessary to make healthy food choices can significantly improve their long-term health outcomes (Grover and Choudhary, 2017; Yang et al., 2017; LeRouge et al., 2019; Depboylu, 2023).

However, many adolescents have limited food literacy skills, which can hinder their ability to plan, manage, select, prepare, and consume healthy foods (Bereznay et al., 2019). Interventions focused on promoting health literacy related to eating disorders in non-clinical settings have the potential to reduce the disease burden associated with common eating disorders in adolescence (Patton et al., 2008).

In this context, our study aims to evaluate the effectiveness of a targeted health literacy intervention designed to improve adolescents’ food literacy and promote healthier eating habits. The intervention focuses on enhancing their understanding of nutrition, improving their self-regulation skills, and ultimately contributing to better overall health outcomes, including a reduction in body mass index (BMI). The health literacy intervention implemented in this study combines educational workshops, interactive sessions, and the use of digital tools such as the MyFitnessPal app to enhance food literacy, which encompasses nutrition knowledge, food label interpretation skills, and cooking abilities.

The study methodology involved the use of a health literacy intervention on healthy eating conducted on 200 adolescent students. The intervention employed was a multifaceted health literacy program specifically designed to enhance food literacy among adolescents and informed by Velardo (2015) who emphasizes the importance of health literacy, nutrition literacy, and food literacy when designing interventions aimed at improving dietary behaviors, with each playing a role in shaping individuals’ dietary behaviors and overall health outcomes. Food literacy, for example, requires a base of nutrition literacy but also includes practical skills such as cooking and an understanding of where food comes from. Velardo argues that effective interventions should be tailored to address the specific components of food literacy, recognizing that improving food-related knowledge alone is insufficient without also developing practical skills and critical thinking about food choices. Our program integrated educational workshops, practical exercises, and digital tools such as the MyFitnessPal app to improve participants’ knowledge of nutrition, food label interpretation, and self-regulation skills. The intervention was theoretically grounded in social cognitive theory (Bandura, 1986), which emphasizes the role of observational learning, social influence, and self-efficacy in behavior change. According to this theory, individuals learn new behaviors not only through direct experience but also by observing the actions of others and the resulting consequences. This approach is particularly relevant for adolescents, who are strongly influenced by their peers and authority figures. The intervention also incorporated elements of self-determination theory (Deci and Ryan, 1985; Ryan and Deci, 2017; Ryan and Deci, 2000), which focuses on the importance of fulfilling three fundamental psychological needs: autonomy, competence, and relatedness. By promoting these aspects, the intervention aimed to intrinsically motivate adolescents to make healthier food choices by feeling competent in their dietary decisions and supported by their environment.

This methodology was aimed at evaluating the effects of such an intervention on food knowledge, eating habits, and the overall health of adolescents. The method included the use of specific tools to assess these effects and collected quantitative and qualitative data. The study sample consisted of adolescent students selected from various high schools. The health literacy intervention was based on a series of educational workshops, interactive sessions, and educational materials aimed at improving students’ knowledge and eating habits. Before full implementation, the intervention underwent a pilot phase to assess its feasibility and preliminary effectiveness. During this phase, feedback was collected from participants to identify potential issues and opportunities for improvement. Adjustments were made to the educational content and delivery methods to ensure they were appropriately tailored to the target group. During the main intervention, a process evaluation was conducted to ensure fidelity and consistency in its delivery. This process included monitoring the sessions, reviewing practical activities, and tracking participants’ use of digital tools. We primarily focused on enhancing self-regulation skills related to dietary habits, such as goal-setting, planning, and resisting temptations. However, we acknowledge that self-regulation is distinct from practical skills such as cooking or food label interpretation. While our educational workshops did include components aimed at improving these practical skills, the study did not include direct assessments of these competencies. The study was approved by the Institutional Review Board, and all participants (and their legal guardians, in the case of minors) provided written informed consent before participation.

As reported in Table 2, the mean age of participants was approximately 17 years, with a small standard deviation, indicating a relatively homogenous group in terms of age. The initial BMI had a mean of 23.64 with a wider standard deviation, suggesting variability in participants’ body mass index. The Nutritional Literacy (NLit) and Emotional Eating Scale (EES) scores also varied, indicating diverse levels of nutritional knowledge and emotional eating behaviors among participants. The TESQ scores, which measure self-regulation in eating, had a mean of 2.35, with a standard deviation indicating some variability in participants’ ability to regulate their eating behavior.

According to Table 3, there were 89 male participants, constituting 44.5% of the sample, and 111 female participants, making up 55.5% of the sample. This distribution shows a slightly higher representation of female participants in the study.

Table 4 presents Spearman’s bivariate correlations for several variables, including body mass index (BMI), Nutritional Literacy (NLit), Emotional Eating after Depression (DEP), Emotional Eating after Anger (ANG), Emotional Eating after Anxiety (ANX), Emotional Eating Scale (EES), and several self-regulation strategies as measured by the Tempest Self-Regulation Questionnaire for Eating (TESQ) among others. The table provides correlation coefficients that measure the strength and direction of association between pairs of these variables, with **p < 0.01 indicating statistically significant correlations. Key findings from Table 3 include the following:

Significant positive correlations among emotional eating measures (DEP, ANG, ANX, and EES) indicate that higher levels of emotional eating in one category (e.g., depression) are associated with higher levels of emotional eating in other categories (e.g., anger and anxiety).

Negative correlations between Emotional Eating Measures and Self-Regulation Strategies (TEMP, MEAN, and GOAL) suggest that individuals who report higher use of self-regulation strategies to manage their eating behavior tend to report lower levels of emotional eating. This highlights the potential protective role of self-regulation skills against emotional eating behaviors.

BMI’s correlation with Emotional Eating and Self-Regulation Strategies is notable. BMI shows a positive correlation with emotional eating measures, indicating that higher BMI values are associated with higher levels of emotional eating. Conversely, BMI is negatively correlated with self-regulation strategies, suggesting that individuals with higher BMIs may utilize fewer self-regulation strategies in their eating behaviors, or that effective use of such strategies could be associated with lower BMI.

Nutritional Literacy (NLit) shows very low or insignificant correlations with most other variables, indicating that nutritional knowledge alone may not be strongly associated with emotional eating behaviors or the use of specific self-regulation strategies. This suggests that while knowledge is important, it might not directly influence these behaviors without the support of practical skills or interventions designed to change behaviors.

As reported in Table 5, the mean BMI at baseline was 23.64, with a slight decrease post-intervention (M = 23.45) and at follow-up (M = 23.04). There was a noticeable increase in mean nutrition literacy from baseline (M = 49.08) to post-intervention (M = 56.06) and slightly decreasing at follow-up (M = 54.42), indicating an improvement after the intervention. The mean EES score decreased from baseline (M = 61.23) to post-intervention (M = 59.26) and further at follow-up (M = 57.92), suggesting a reduction in emotional eating. The self-regulation questionnaire scores showed an increasing trend from baseline (M = 2.35) to post-intervention (M = 2.62) and follow-up (M = 2.75), indicating improved self-regulation skills over time.

The Shapiro–Wilk test results for normality indicated that the distributions of BMI, NLit, EES, and TESQ at baseline were not normally distributed (p-values <0.05), which suggests that non-parametric tests should be used for further analyses.

Given that the data dо not follow a normal distribution for most variables, we used the Wilcoxon test (a non-parametric alternative to the t-test) to compare pre- and post-intervention scores, which indicated significant changes for some variables.

The Wilcoxon signed-rank tests comparing baseline versus post-intervention and baseline versus follow-up measurements for body mass index (BMI), Nutrition Literacy (NLit), Emotional Eating Scale (EES), and Tempest Self-Regulation Questionnaire for Eating (TESQ) yielded the following p-values:

BMI Changes. Baseline vs. Post-intervention: p-value <0.001; Baseline vs. Follow-up: p-value <0.001. The significant change in BMI indicates that the intervention had a marked effect on reducing BMI from pre-intervention values to post-intervention values. This suggests success in achieving the goal of improving body weight or body composition of the individuals involved.

These results suggested that the intervention significantly impacted BMI, Nutrition Literacy, and self-regulation skills (as measured by TESQ), with improvements evident both immediately post-intervention and at follow-up. However, changes in Emotional Eating (as measured by EES) were not statistically significant, indicating that the intervention may not have had a clear impact on emotional eating behaviors.

The Friedman test results clearly show that there were significant differences between the scores of all the considered variables (BMI, NLit, EES, and TESQ) at the three measurement times (pre-intervention, post-intervention, and follow-up) (see Table 6). This demonstrates the lasting impact of the intervention beyond the period immediately following its conclusion. For BMI and NLit, not only the immediate impact was confirmed but also the persistence over time of this effect on body mass index and nutritional knowledge. For EES, although there were no significant changes in the pre- and post-analysis, the Friedman test indicated that, considering the follow-up, there were significant changes over time (p-value <0.001). For TESQ, similarly, it was confirmed that the intervention had a substantial and lasting effect on improving food self-regulation skills.

Table 7 provides correlation coefficients along with p-values, highlighting the strength and significance of the relationships between the variables.

Baseline NLit vs. Changes in BMI: The correlation coefficient of 0.165 with a p-value of 0.019 suggests a statistically significant, albeit weak, positive relationship between initial nutritional literacy levels and changes in BMI. This indicates that higher baseline levels of nutritional literacy might be associated with greater changes in BMI, suggesting that a better understanding of nutrition could positively influence BMI outcomes to some extent.

Baseline TESQ vs. Changes in EES: A stronger correlation coefficient of 0.310 with a p-value of 0.001 demonstrates a statistically significant, moderate relationship between initial self-regulation skills (as measured by TESQ) and changes in emotional eating (as measured by EES). This suggests that individuals who initially report better self-regulation in eating are more likely to experience significant changes in their emotional eating behaviors. This could imply that enhancing self-regulation skills may be an effective strategy in addressing emotional eating.

The regression analysis in Table 8 highlights the nuanced dynamics between demographic factors, nutritional literacy, and their collective impact on BMI changes. The significance of nutritional literacy underscores the value of targeted nutritional education in influencing positive health outcomes. The lack of a significant gender effect suggests that, in this sample, gender does not have a meaningful impact on the intervention’s effectiveness regarding BMI changes. The coefficient for age is −0.228 with a statistically significant p-value of 0.002. This suggests that age negatively affects BMI changes, implying that older adolescents might experience smaller changes in BMI compared to younger ones. This could be due to various factors, including differences in metabolic rates, lifestyle choices, or responsiveness to the intervention based on age. The initial level of nutritional literacy has a coefficient of 0.120 with a p-value of less than 0.001, indicating a positive and statistically significant impact on BMI changes. This implies that higher initial nutritional literacy is associated with greater changes in BMI, reinforcing the importance of nutritional education as part of interventions aimed at BMI management.

The food literacy intervention carried out has demonstrated the importance of combining different strategies to promote healthy nutrition among adolescents. Going deeper into the results, it is possible to better understand how these strategies have contributed to improving food knowledge, eating habits, self-regulation, and the overall health of adolescents.

The increase in food knowledge among adolescents is a key outcome of the intervention. By educating students on the principles of a balanced diet, the importance of various nutrients, and how to read and interpret food labels, the intervention has provided them with the necessary tools to make informed food choices. This aspect is fundamental as the ability to understand and apply nutritional information is an essential first step toward adopting healthy eating habits.

The evident result of the increase in food knowledge among the participating adolescents is not only an indicator of the success of the educational intervention but also a critical foundation for the adoption of informed food choices. In-depth knowledge about nutrients, the caloric values of foods, and the composition of healthy meals is essential to combat improper eating habits that can lead to long-term health problems, such as obesity and diseases related to diet (Lee et al., 2022; Liu et al., 2022).

The intervention highlighted how self-regulation practices can positively influence adolescents’ eating habits. Strategies such as avoiding temptations, setting dietary goals and rules, and reflecting on personal goals can help resist the temptations of unhealthy foods and prefer more nutritious options. This approach proved effective in promoting an increase in fruit and vegetable consumption and a reduction in the intake of fast food and processed snacks. The improvement in self-regulation in eating habits testifies to the effectiveness of the intervention in promoting effective coping strategies in the face of temptations of unhealthy foods and in portion management. Self-regulation skill is crucial for maintaining a balanced diet and managing body weight, especially in an era where adolescents are constantly exposed to unhealthy food stimuli through media and social environment (Diotaiuti et al. (2021a); Guzek et al., 2022; Guo et al., 2023).

The adoption of apps for tracking food and physical activity, such as MyFitnessPal, provided adolescents with a practical and interactive method to monitor their diet and caloric balance. This not only increased their awareness of their eating habits but also facilitated the management and optimization of nutrient and calorie intake. The use of digital technologies in food education offers significant potential to improve engagement and learning among adolescents (König et al., 2021).

The positive effect of the intervention on adolescents’ BMI underscores the importance of food literacy for overall health. An improved BMI reflects not just a better body composition but also a reduced risk of developing health problems related to diet, such as obesity and metabolic diseases. These results confirm that well-structured educational interventions can have a significant impact on the long-term health of adolescents (Reid et al., 2021; Taleb and Itani, 2021).

The improvement in body mass index (BMI) signals a direct positive impact of the intervention on the physical health of adolescents. BMI is a key indicator of health status and the risk of developing chronic diseases associated with overweight and obesity. An improvement in this parameter reflects not only a reduction in the intake of high-energy-density foods but also an increase in physical activity, highlighting the importance of a holistic approach to health that integrates nutrition and exercise (Koca and Arkan, 2020; Ruiz et al., 2021).

The interpretation of the results obtained from the food literacy intervention conducted on adolescents reveals a series of significant considerations that warrant detailed exploration to fully understand their impact and implications. These results lay the groundwork for further investigations and implementations in the field of food education and health promotion among adolescents. It is crucial to recognize that food literacy is not limited to the mere acquisition of knowledge but also includes the development of practical competence, such as reading food labels, preparing healthy meals, and effectively managing food resources (Ares et al., 2023; Li et al., 2022).

The study also indicated that there was no statistically significant change in Emotional Eating Scale (EES) scores following the eating literacy intervention among adolescents, suggesting that the intervention did not significantly alter emotional eating behaviors, which are often triggered by negative emotions such as anxiety, anger, or depression. Emotional eating, the act of consuming food in response to emotional rather than physical hunger, can lead to unhealthy eating patterns and potentially contribute to weight gain or the development of eating disorders (Erdem et al., 2023; Joseph et al., 2023; Xiang et al., 2023; Limbers and Summers, 2021).

The lack of significant change in emotional eating behaviors post-intervention highlights the complexity of addressing such behaviors through eating literacy programs alone. It underscores the necessity of integrating more targeted psychological or behavioral strategies within food literacy interventions to effectively manage emotional triggers for eating. This outcome emphasizes the importance of a multifaceted approach to food literacy interventions that not only educates adolescents about nutritional knowledge and self-regulation skills but also addresses the emotional aspects of eating (Bektas and Gürkan, 2023; Francis et al., 2023; Aloudah, 2021; Diotaiuti et al., 2020).

By incorporating strategies to better manage emotional responses that lead to eating, such interventions can contribute to more balanced eating behaviors and improve overall mental and physical health among adolescents. Future research should explore the incorporation of emotional regulation techniques and psychological support within eating literacy programs to enhance their effectiveness in reducing emotional eating among adolescents (Bui et al., 2021; Diotaiuti et al. (2021b); Woods-Townsend et al., 2021; Shriver et al., 2020).

The comparison of the results of the food literacy intervention among adolescents with those of previous studies highlights some interesting aspects and confirms the growing evidence on the effectiveness of educational interventions in promoting healthy eating habits in this critical age group.

Previous studies have already highlighted the importance of food education among adolescents, showing how targeted interventions can improve nutritional knowledge and positively influence food choices. For example, the effectiveness of school nutritional education programs in improving understanding and adoption of healthier diets has been documented in various research (Heikkilä et al., 2021; Noronha et al., 2020; Asakura et al., 2017; Egg et al., 2020). These programs, similar to the described intervention, have utilized multi-component educational approaches to influence both the knowledge and behavior of students.

A distinctive aspect of the intervention under examination is the intensive use of digital tools, such as the MyFitnessPal app, to promote self-regulation and the tracking of food intake and physical activity. This approach aligns with the research by Kloss and Bittlingmayer (2017), which emphasized the importance of eHealth literacy in promoting healthy eating behaviors among adolescents. The inclusion of digital technologies represents a relatively new feature in the field of food education and reflects the adaptation of interventions to the habits and preferences of modern adolescents.

The impact of the intervention on the BMI of adolescents echoes the findings of studies such as those reported by Jacob et al. (2021), which demonstrated how school-based interventions can have positive effects not only on knowledge and behavior but also on physical health measures such as BMI. This reinforces the idea that well-designed and well-executed interventions can have tangible beneficial effects on the physical health of adolescents.

However, it is important to note that, while the described intervention and similar studies show promising results, the literature also indicates the need for long-term interventions and follow-ups to maintain behavioral changes (Bailey et al., 2019; Diotaiuti et al. (2021c); Forray et al., 2021; Larose et al., 2023). Many studies underline the importance of continuous support, education, and environment to sustain healthy eating habits over time (Chaudhary et al., 2020; Medeiros et al., 2022; Nagy-Pénzes et al., 2022).

Our study highlights the importance of self-regulation in improving dietary behaviors among adolescents. However, we recognize the need to directly measure practical skills in future research. Practical skills, such as cooking and food preparation, are critical components of food literacy that were addressed in our intervention but not formally assessed. Future studies should incorporate these measures to provide a more comprehensive evaluation of food literacy interventions.

The food literacy intervention among adolescents, despite its limitations, offers significant implications for both clinical practice and future research. These insights can guide the evolution of health education programs and inform the direction of subsequent investigations.

The insights derived from this study emphasize the need for multidisciplinary approaches and the use of digital technologies in food education for adolescents. A well-designed program that combines theory with practical activities and the use of digital tools can significantly improve food knowledge, eating habits, and the overall health of adolescents. The importance of these findings lies in their applicability to future health education programs, indicating ways to further enhance the effectiveness of food literacy interventions.

The intervention has demonstrated that food education and literacy can have a significant impact on adolescents’ eating habits, improving their overall health and long-term wellbeing. These results highlight the importance of well-structured food education programs that are capable of addressing the specific needs of this age group and promoting positive change in eating behavior. It is crucial to continue investing in research and development in this field to expand our understanding and optimize intervention strategies, in order to ensure a healthier future for younger generations.

In conclusion, our intervention is situated within a well-established research context that supports the effectiveness of food education and nutritional literacy among adolescents. The addition of digital elements and focus on self-regulation strategies represent significant evolutions in intervention design, offering new directions for future research and educational practice. The convergence between the results of the intervention and those of previous studies strengthens the argument for continuous and innovative investments in food education and health promotion among adolescents.