The effect of educational intervention on weight loss in adolescents with overweight and obesity: Application of the theory of planned behavior

BACKGROUND The increased prevalence of overweight and obesity in children and adolescents is associated with type 2 diabetes, hypertension, dyslipidemia, and cardiovascular diseases. The theory of planned behavior (TPB) efficiently explains the ability of perceived behavioral control and possibly attitude to enhance the motivations of the obese people to lose weight. Our aim was to investigate the effect of TPB-based education on weight loss in obese and overweight adolescents. METHODS In an interventional study, simple random sampling was used to select 86 overweight and obese adolescents aged 13-18 years in the pediatric clinic at the Isfahan Cardiovascular Research Institute. Anthropometric measures and TPB constructs were collected using a researcher-made questionnaire. The questionnaires were filled out before and six weeks after the intervention. Participants received 5 sessions of training based on the constructs of the TPB. RESULTS A significant increase was observed in the mean score for knowledge and TPB constructs (attitudes, subjective norms, perceived behavioral control, intention, and behavior) six weeks after the educational intervention (P < 0.001). Moreover, significant decrease in body mass index (P < 0.001), weight (P = 0.001), and waist circumference (P < 0.001) of adolescents were found after the educational intervention. CONCLUSION The TPB-based interventions seem to be effective in losing weight in obese and overweight adolescents. This theory serves as a helpful theoretical framework for health-related behaviors and can be an appropriate pattern to plan for educational interventions.