Guidelines-Driven Educational Intervention Promotes Healthy Lifestyle Among Adolescents and Adults: A Serbian National Longitudinal Study

Background and objectives: The effectiveness of short-term focused educational programs to change health behaviors across large populations seems to be poorly described so far. The main aim of the present study was to evaluate an age-specific 45-min educational program, designed in accordance with the current U.S. Department of Health and Human Services and U.S. Department of Agriculture dietary guidelines and physical activity (PA) guidelines, among adolescents and adults. Materials and Methods: We evaluated the health-promoting lifestyle habits by the Health-Promoting Lifestyle Profile (HPLP-II) at baseline and following 6–8 weeks post-education in a nationally representative sample of Serbian adolescents and adults (n = 3822). Results: The percentage of adolescents eating 3–5 servings of vegetables per day increased at follow-up (20.1% versus 23.1%, p = 0.001), with significantly more adolescents regularly reading food labels (from 12.2% at baseline to 14.2% at follow-up; p = 0.02). Taken together, mean HPLP-II scores in adolescents significantly improved for both diet (0.05 points; p < 0.0001) and PA (0.09 points; p < 0.0001), and for PA in adults (0.08 points; p < 0.0001). Hierarchical multiple regression analysis revealed that our model as a whole (including time of testing as a predictor variable, and age and gender as control variables) explained 3.0% of the variance in mean HPLP-II scores for diet (p = 0.942) and 3.0% for PA (p = 0.285) in adolescents, and 1.1% of the variance in HPLP-II scores for diet (p = 0.781) and 1.9% for PA (p = 0.075) in adults, respectively. Conclusions: It appears that a brief focused education can positively tackle unhealthy lifestyles in promoting good health in general population. Different modes of interactive communication used here appeared to strengthen participants’ capacities for lifestyle changes.