Associations between substance use and body mass index: moderating effects of sociodemographic characteristics among Taiwanese adolescents.

The aim of this study was to analyze the association between substance use and body mass index (BMI) among adolescents in Southern Taiwan. A total of 10,259 adolescent students aged 11-19 years were selected by stratified random sampling for proportional representation of districts, schools and grades in Southern Taiwan, and completed the questionnaires. The body weight, body height, experience of substance use and sociodemographic characteristics including sex, age, residential background and paternal/maternal educational levels were collected. The association between substance use and BMI, and the moderating effects of sociodemographic characteristics were examined. After adjusting for sociodemographic characteristics, BMI was higher for adolescents who smoke cigarettes or drink alcohol than for those who do not regularly smoke or drink. Chewing betel nuts and using illicit drugs were not significantly associated with BMI. Paternal education level had a moderating effect on the association between smoking and BMI. Smoking, alcohol drinking, and low paternal education level were associated with higher BMI among adolescents. Thus, healthcare professionals should pay more attention to the weight-related problems among these adolescents.