Objective: To define relationships between smoking status, body mass index (BMI), waist and hip circumferences (WC, HC) and waist to hip ratio (WHR).
Design: Further analysis of the cross-sectional Scottish Health Survey 1998 data.
Subjects: Nationally representative sample of 9047 adults aged 16-74 y.
Results: Body mass index (BMI) was lower in current smokers and higher in ex-smokers (P<0.001) when compared with nonsmokers in the survey population as a whole. After adjustment for confounding factors (age, social class, physical activity and alcohol intake), these differences still remained. However, examination of age categories showed no such differences in BMI between current smokers and nonsmokers in men aged 16-24 y or women aged below 55 y. In the age category 16-24 y, prevalence of cigarette smoking was highest at 51% (men) and 43% (women) in obese subjects and lowest at 35% (men) and 33% (women) in people with BMI of 25-30 kg/m(2). For women current smokers, mean WC and WHR were higher and HC was lower compared with nonsmokers (P<0.001). In men, only HC was lower in current smokers compared with nonsmokers for the entire sample (P<0.001).
Conclusion: Cigarette smoking is associated with a lower BMI in adults over 24 y particularly in men, but not in younger people. In women, smoking is linked to the development of central adiposity. The gender-related central adiposity of men is not further increased by smoking, but a lower HC could suggest a reduction in muscle mass.