No considerable long-term weight gain after smoking cessation: evidence from a prospective study.

The aim of the study was to analyse predictors of the body mass index (BMI) after smoking cessation. The sample included 4075 residents aged 18-64 years in a northern German area (participation rate 70.2%), drawn randomly from the resident registration files, among them 1545 current and 903 former daily smokers. The current smokers were followed up 36 months after baseline. Face-to-face in-home computer-aided interviews (Composite International Diagnostic Interview) including questions about body weight and height at baseline and postal questionnaires at follow-up were employed. The data reveal that the number of cigarettes smoked at time of peak consumption in life contributed substantially, and years of abstinence from daily smoking contributed marginally to the BMI in a general linear model. It is concluded that the contribution of smoking cessation to the BMI increase was practically negligible. Efforts to prevent weight gain after smoking cessation should focus especially on heavy smoking.