Can High Schools Be an Effective Setting to Promote Healthy Lifestyles? Effects of a Multiple Behavior Change Intervention in Adolescents

Abstract

Purpose: The main aim was to examine the effects of a school-based intervention on multiple health behaviors in adolescents, such as 24-hour movement behaviors (i.e., physical activity, sedentary time, and sleep duration), diet, and substance consumption (i.e., alcohol and tobacco). Another aim was to examine intragender differences in the effectiveness of the programme.

Methods: A quasi-experimental design was carried out in two secondary schools throughout one academic year. A final sample of 210 students participated: 105 in the control (Mage = 13.07 ± 0.63) and 105 in the experimental school (Mage = 13.05 ± 0.59). A multicomponent school-based intervention was conducted by teachers in the experimental school via curricular (i.e., tutorial action plan, interdisciplinary project, and school break) and extracurricular (i.e., family involvement, institutional and noncurricular activities, and dissemination of health information and events) actions to promote adolescents' healthy lifestyles. Physical activity and sedentary time were measured by accelerometers, and the rest of health behaviors by using self-reported scales.

Results: Experimental school students showed a significant improvement in meeting specific and general combinations of 24-hour movement guidelines, sedentary screen time levels, nap duration, (un)healthy diet scores, breakfast intake, and soft drink consumption compared to both control school students and their baseline values (p >.05). Active commuting and substance consumption rates only showed a significant improvement compared to control school students (p >.05). Although the intervention programme was effective in improving health-related behaviors in both genders, a large effect size was observed in boys.

Conclusions: Conducting multiple health behavior interventions becomes essential to improve adolescents' healthy lifestyles.

Keywords: Adolescent health; Diet; Physical activity; Screen time; Sedentary behavior; Simultaneous health behavior interventions; Sleep; Substance abuse prevention.