In this paper is a secondary analysis using raw data from the Korea Health Statistics 2013: Korea National Health and Nutrition Examination Survey. Total of 572 subjects were included in the analysis. Data were analyzed using descriptive statistics, correlation and multiple regression with SPSS/Win 21.0 program. Results of the analysis reported that the prevalence of obesity was 20.01%. The study confirmed that it has correlations with gender, age, body shape perception, how an individual adolescent has controlled one’s weight over the last one year, if the individual has ever drunk alcoholic beverages, how many hours one would sleep a day on average, if one has smoked once in a while and how often one would exercise per week. The above mentioned dependent factors were explicable causes of 66.9% of adolescent obesity according to the logistic model. In the light of that, the study now suggests that when any relevant fields try to educate adolescents on obesity, they should teach the adolescents differently depending on how an individual adolescent has controlled one’s weight over the last one year, gender and age and in addition, that during the obesity education, the adolescents should be also led to see significance of mental health such as body shape perception.