Background and Objective: Adolescence is a critical period
that underlies lifestyle in later periods of life. The aim of this study was
evaluation of the impact of a model based intervention on lifestyle among
adolescents.   Materials and Methods: A group randomized clinical trial
for assessing the effect of educational intervention on 365 adolescents (192
females and 173 males) was designed. Adolescent life style questionnaire (ALQ)
and a demographic scale were used for data collection. Data were collected
before and two weeks after the intervention with regard to PRECEDE PROCEED
model. Statistical tests such as Chi 2, independent and paired t-test were used
by SPSS software version 17 for data analysis.   Results: The mean age of adolescents was 15.77 years (SD =
0.74) years. A significant increment in lifestyle score was obtained between
before and after intervention among intervention groups (p < 0.01). The
standard mean of physical activity among males and the standard mean of social
support among females were higher than the other gender.    Conclusion: The findings suggest that an educational
intervention based on PRECEDE PROCEED model may be effective for lifestyle
improvement among adolescents. In light of these findings, necessity of
gender-based healthy life style education among adolescents should be
considered further.