Zohreh Vafadar - Baqiyatallah University of Medical Sciences
Reza Reazei - Baqiyatallah University of Medical Sciences
Ali Navidian - Zahedan University of Medical Sciences

Introduction: Childhood and teenager obesity as an international growing health problem is predisposing adolescents to chronic, incapacitating and lethal diseases in adulthood. This situation has motivated many researchers to establish effective weight controlling programs with psychological approaches.The purpose of this study was to determine the effect of motivational interviewing on weight self-efficacy lifestyle of teenaged boys suffering from overweight or obesity.Method: This research is a controlled clinical trial in pretest and post-test design with repeated measurments which was conducted on a control group plus ۲ experimental groups in ۱۳۹۱. Sample and control groups comprised ۹۰ high school students, between ۱۵ to ۱۹ years old, with BMI over ۲۵, who were selected through accessibility sampling then were randomaly allocated to ۲ experimental groups and ۱ control (each group=۳۰). Control group received no intervention. But experimental group ۱ (named instruction group) was administered regular weight controlling instruction by way of diet for ۴ sessions (each was ۲ hours) and experimental group ۲ got likewise extra to motivational interview for ۵ sessions of ۲ hours during ۵ weeks (in ۳ groups of ۱۰ individuals). Data were collected in ۴ stages of measurement via weight self-efficacy lifestyle questionnaire and then were analyzed using statistical tests of one-way analysis of variance and repeated measures analysis of variance.Results: Increase in mean scores of self-efficacy in both experimental groups but more in group ۲ was observed. Comparison of the groups in every stage of the measurement using ANOVA was suggestive of no significant difference through the pretest and post-test; nevertheless, there was significant difference between follow-up-stage ۱ (p=۰.۰۰۲) and follow-up-stage ۲ (p=۰.۰۲۴). Additionally, the comparison of experimental groups using RMANOVA through the four stages of measurement indicated statistically significant difference between experimental group ۲ (p=۰.۰۰۰) and experimental group ۱ (p=۰.۰۰۰) while there was no significant difference as for control group (p=۰.۶۵). Overall, the comparison between groups through the all stages of measurement showed statistical significant difference (p=۰.۰۰۰(.Conclusion: Motivational interviewing along with regular weight controlling instruction can increase weigh self-efficacy lifestyle of teenaged boys with overweight and obesity in order for the change of behavior with regard to weight controlling.

Motivational Interviewing, Obesity, Overweight, self-efficacy, Lifestyle