Tarbiat Modares University (TMU) Health Education and Health Promotion 2588-5715 14 2 2026 04 01 Social Cognitive Theory–Based Intervention to Improve Adolescent Healthy Lifestyle Compliance 247 253 29074 10.58209/hehp.14.2.247 EN P. Razi Department of Health Promotion, Health Polytechnic of Jambi, Jambi, Indonesia 0000-0003-2835-1710 E. Veriza Department of Health Promotion, Health Polytechnic of Jambi, Jambi, Indonesia 0009-0009-1712-5866 S. Surayah Department of Dental Health, Health Polytechnic of Jambi, Jambi, Indonesia 0009-0004-6235-9235 Journal Article 2026 05 24 <strong><span>Aims:</span></strong><span> </span><span>Behavioral modification interventions based on social cognitive theory are needed to improve adolescents’ compliance with a healthy lifestyle. This study aimed to develop and examine the effectiveness of a behavioral modification intervention model based on social cognitive theory for improving adolescents’ compliance with a healthy lifestyle. </span> <strong><span>Materials & Methods:</span></strong><span> This study employed a mixed-methods sequential exploratory design consisting of qualitative and quantitative approaches. The quantitative phase used a one-group pretest–posttest design involving 100 adolescents selected through purposive sampling. Data were collected using a healthy lifestyle compliance questionnaire that had been tested for validity and reliability. The intervention was implemented in four stages: introduction, preparation, action, and maintenance. Data were analyzed using a paired t-test and Cohen’s d effect-size analysis utilizing SPSS 25.</span> <strong><span>Findings:</span></strong><span> </span><span>The mean healthy lifestyle compliance score increased significantly from 61.42±8.53 before the intervention to 78.67±7.14 after the intervention, with a mean difference of 17.25 points (p<0.001; 95% CI: 15.09–19.41). The intervention demonstrated a large effect size, with a Cohen’s d value of 1.24. Multivariate analysis showed that self-efficacy (p<0.001), self-regulation (p=0.001), family support (p=0.003), and peer support (p=0.005) were significantly associated with healthy lifestyle compliance after the intervention. </span> <strong><span>Conclusion:</span></strong><span> </span><span>The behavioral modification intervention model based on social cognitive theory is effective in improving adolescents’ compliance with a healthy lifestyle. </span> https://hehp.modares.ac.ir/article_29074_e3030406173074724559c34666f5830f.pdf