Association between adolescent body-mass index and adulthood smoking.

Introduction: Studies increasingly find a prospective association between adolescent weight status and adverse physical health outcomes. However, less is known about the long-term consequences of adolescent body weight on the adoption of health risk behaviors. This study sought to determine whether adolescent body mass index (BMI) was associated with cigarette smoking in adulthood.

Methods: 6,683 non-smoking adolescents were interviewed at baseline (1996, age 11-20) and at follow-up (2008, age 24-32) as part of the National Longitudinal Survey of Adolescent Health. Logistic and fractional regression models tested the association between adolescent BMI and smoking status and frequency in adulthood. Respondent weight and height were measured at baseline and converted into age and sex-specific BMI z-scores. Being a smoker was defined as smoking at least once in the past 30 days, while smoking frequency was defined as the proportion of days smoked over the past 30 days. Both outcomes were measured at follow-up.

Results: Adolescent BMI was positively associated with the transition from non-smoking to smoking 12 years later for women but not men. Adolescent BMI was also positively associated with smoking frequency among women smokers. Both associations persisted after adjusting for established risk factors and were robust to sensitivity analyses.

Conclusion: Adolescent BMI was strongly associated with increased cigarette smoking behavior in adulthood for women, even after adjusting for important risk factors.

Implications: Using a large, nationally representative sample, this study found that adolescent BMI was positively associated with smoking behavior during adulthood for women but not men. These results have potentially important public health implications for future smoking rates in the US, as the prevalence of overweight and obesity among US adolescent females continues to grow. Thus, it may be important for smoking prevention interventions to prioritize overweight adolescent females moving forward.