Objective: To investigate whether current smoking and lifetime snuff use are associated with a lifetime history of major (>/=5 kg) intentional weight loss in young adults, and to examine the dependence of this association on familial factors.
Design: Cross-sectional population-based questionnaire survey of young adult Finnish twins participating in the fourth wave of the longitudinal FinnTwin-16-study in 2000-2002.
Subjects: A total of 4521 young adult Finnish twins aged 23-27 y.
Measurements: Questionnaire data on the number of intentional weight-loss episodes and on body mass index (BMI), cigarette smoking and snuff use, educational level, and number of subjects' own children.
Results: Current daily smoking was strongly associated with a history of two or more intentional major weight-loss episodes (lost >/=5 kg twice or more lifetime) both in women odds ratio (OR 1.87; 95%; confidence interval (CI) 1.39-2.50) and in men (OR 2.00; 95% CI 1.37-2.90). Frequent lifetime snuff use was statistically significantly associated with recurrent intentional weight loss episodes in men (OR 1.51; 95% CI 1.08-2.13). Among the twin pairs discordant for daily smoking, the smoking twin was more likely than the nonsmoking co-twin to have recurrent intentional weight-loss episodes (OR 1.57; 95% CI 1.03-2.41). These episodes were also strongly associated with high BMI. Education was inversely related to recurrent intentional weight-loss episodes in men.
Conclusion: Tobacco use is strongly associated with a lifetime history of recurrent intentional major weight-loss episodes in early adulthood. This represents a major challenge to existing attitudes on smoking prevention and the promotion of healthful weight control.