Relationships between Body Image, Body Mass Index, and Smoking in Korean Adolescents: Results of a Nationwide Korea Youth Risk Behavior Web-based Survey

Objective: This study assessed the association between subjective body image or objective body mass index(BMI) and the risk of daily smoking in Korean adolescents, with a purpose of identifying the most suitablemodels. Materials and
Methods: Using the 2013 9th Korea Youth Risk Behavior Web-based Survey data for72,435 students, odds ratios were calculated for daily smoking in the past month, according to the subjectivebody image and calculated BMI using a respective multiple logistic regression model. The combined effect ofthese two factors was also analyzed by pairing a BMI category with a subjective body image category, usingodds ratios for the same event within each sex group.
Results: Among the surveyed students, 7.2% of boys and1.8% of girls were classified as daily smokers. Students who perceived themselves as being very obese tendedto be at lower risk of daily smoking (OR=0.61 in boys with 95% CI=0.47 to 0.79; OR=0.66 in women with 95%CI=0.47 to 0.93). In addition, boys within the obese or overweight BMI category showed a lower risk of dailysmoking (OR=0.86, 95% CI: 0.77-0.96). Lean BMI was significantly associated with higher odds ratios for dailysmoking only in female students (OR=1.24, 95% CI: 1.02-1.52). When pairing these two objective and subjectivefactors, results suggested that subjective body image has a greater effect on daily smoking than BMI in bothboys and girls.
Conclusions: In both male and female students, subjective body image had a greater effect ondaily smoking than body mass index. A model using the combination of BMI and subjective body image was thebest fit in girls, in contrast to the model using subjective body image only best suitable in boys, for the predictionof daily smoking. These results including several factors associated with daily smoking in Korean students,provide useful data for the development and implementation of smoking intervention and cessation programsfor adolescents.