The increasing prevalence of lifestyle-related diseases, such as obesity and type 2 diabetes, highlights the urgent need for effective school-based nutritional interventions. Adolescence is a crucial period for developing dietary habits, making it imperative to implement programs that enhance both knowledge and behaviors to prevent long-term health complications. However, there is still debate over the effectiveness of such interventions, as knowledge acquisition does not always lead to sustainable behavioral change. Understanding the gap between theoretical understanding and practical application is essential for designing more effective educational programs.

This study aims to assess the impact of a nutrition education workshop on secondary school students’ knowledge and eating habits. A quasi-experimental design was employed, with an experimental group receiving the intervention and a control group not exposed to any treatment. The Nutrition Knowledge Questionnaire (NKQ) and the Eating Habits Scale (EHS) were utilized as measurement tools, both validated instruments assessing pre- and post-intervention differences. The NKQ measured students’ theoretical understanding of nutrition concepts, while the EHS evaluated their actual dietary practices.

The sample consisted of 100 students (45 males, 55 females), aged 14-17 years, recruited from three secondary schools in the Valencian Community. The participants were randomly assigned to two groups: an experimental group (n = 50) and a control group (n = 50). The intervention comprised six educational sessions over three weeks, covering essential topics such as balanced diets, food groups, portion control, meal planning, and reading nutrition labels. The sessions included a mix of expository and participatory activities, encouraging student engagement through group discussions, interactive games, and case analyses. These diverse learning techniques were designed to improve both theoretical knowledge and practical application.

Findings indicated a significant improvement in nutrition knowledge in the experimental group (p < 0.001, r = 0.847). The control group, however, showed only minor improvements in knowledge (p < 0.05, r = 0.245), suggesting that without an intervention, students' nutrition knowledge remains relatively stable. In contrast, no significant changes in eating habits were observed in either group (experimental: p = 0.335, r = 0.096; control: p = 0.512, r = 0.058). This suggests that while knowledge increased in the experimental group, behavioral modifications did not emerge within the short intervention period.

Several factors may explain these results. One primary limitation was the short duration of the intervention, which may not have been sufficient for behavior changes to manifest. Behavioral modifications often require prolonged exposure and consistent reinforcement. Additionally, the lack of external motivators, such as parental involvement or school-wide policy changes, may have impeded the students’ ability to translate knowledge into sustained eating behavior changes. Research suggests that habit formation is a gradual process, necessitating continuous engagement and environmental support.

Moreover, socioeconomic factors may have played a role in limiting dietary changes. Access to healthy foods, family eating habits, and cultural dietary preferences can influence students’ abilities to adopt healthier eating behaviors. Future research should incorporate a broader range of participants, including students from different socioeconomic backgrounds, to better understand these external influences.

The study underlines that while educational workshops are effective in improving theoretical knowledge, their impact on dietary behaviors is more complex. Future interventions should incorporate long-term strategies, family participation, and school engagement to optimize effectiveness. The inclusion of school cafeterias, parental education initiatives, and community-based interventions may enhance the likelihood of lasting behavioral changes. Additionally, peer support mechanisms could be leveraged to encourage students to make healthier food choices.

This study adopted a quasi-experimental design with a pretest-posttest control group approach to assess the effectiveness of a nutrition education workshop. The research was conducted in three secondary schools in the Valencian Community, Spain, chosen to ensure a diverse sample representing public, private, and semi-private institutions. The final sample consisted of 100 students (45 males and 55 females) aged between 14 and 17 years. Participants were randomly assigned to either the experimental group (n = 50), which received the intervention, or the control group (n = 50), which did not participate in the workshop. To measure the effectiveness of the program, two validated instruments were used: 1. Nutrition Knowledge Questionnaire (NKQ) (Sánchez-Socarrás et al., 2015): A 20-item multiple-choice questionnaire designed to assess students' theoretical knowledge of nutrition, including food group identification, nutritional benefits, and label interpretation. Scores were adjusted to a 0-10 scale. 2. Eating Habits Scale (EHS) (Lima-Serrano et al., 2012): A 15-item Likert scale assessing students' dietary habits, with responses ranging from 1 (never) to 5 (always). Scores were normalized to a 0-10 scale. The intervention consisted of six structured educational sessions, each lasting one hour, over three weeks. The sessions followed a blended learning methodology, combining theoretical presentations with interactive and practical components, such as: 1. Introduction to Healthy Eating 2. Understanding Food Groups 3. Portion Control and Balanced Meals 4. Meal Planning Strategies 5. Interpreting Nutrition Labels 6. Sustaining Healthy Eating Habits Data were collected using pretest and posttest assessments, administered at the beginning and end of the intervention. The study employed quantitative analysis using SPSS v.29. Since the data distribution was found to be non-normal (Kolmogorov-Smirnov test, p < 0.001), non-parametric tests were applied: • Wilcoxon Signed-Rank Test: To evaluate within-group differences between pretest and posttest results. • Mann-Whitney U Test: To compare posttest scores between the experimental and control groups. Ethical approval was obtained from the University Ethics Committee, and informed consent was secured from both students and their legal guardians before participation. Measures were taken to ensure confidentiality and anonymity throughout the study.

This study demonstrates that a nutrition education workshop significantly improved students’ nutrition knowledge, as evidenced by the increased posttest scores in the experimental group (r = 0.847, p < 0.001). The control group, while showing minor improvements in knowledge (r = 0.245, p < 0.05), did not experience a significant increase compared to the experimental group. However, the intervention did not lead to significant changes in eating habits in either group (experimental: p = 0.335, r = 0.096; control: p = 0.512, r = 0.058), highlighting the persistent gap between knowledge acquisition and behavioral change. One of the primary limitations of the study was the short duration of the intervention. Behavioral change is a gradual process that requires sustained reinforcement, and a three-week program may not provide enough time for students to integrate new eating habits into their daily routines. Additionally, external influences, such as parental dietary habits, socioeconomic status, and school meal availability, likely played a role in limiting the intervention’s impact on behavior. Future interventions should incorporate longer durations and multifaceted approaches, including parental engagement, school-wide policies, and hands-on activities such as meal preparation workshops. Research indicates that habit formation is reinforced by consistent exposure, suggesting that long-term follow-ups would be beneficial in assessing the sustainability of knowledge retention and behavior modification. Moreover, implementing peer support mechanisms, goal-setting strategies, and digital applications to track progress may enhance engagement and motivation. Encouraging collaborative activities where students can apply their knowledge practically could help bridge the gap between learning and implementation. In conclusion, while the workshop successfully enhanced nutrition knowledge, its limited impact on eating behaviors underscores the need for holistic interventions that extend beyond the classroom. Future studies should explore integrated approaches combining education, behavioral strategies, and environmental changes to achieve meaningful and sustainable dietary improvements among adolescents.

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