Can the increasing weight of Australians be explained by the decreasing prevalence of cigarette smoking?

In Australia there has been a recent increase in the body mass index (BMI) of the population and a decrease in smoking prevalence. Data from the three risk factor prevalence surveys conducted by the National Heart Foundation of Australia in 1980, 1983 and 1989 were analysed to determine if the increase in BMI could be explained by the decrease in smoking. For men in all age groups and for women aged 50 years or over, there were parallel increases in mean BMI for current smokers, ex-smokers and never smokers. For women under 50 years, the pattern of increasing BMI over time was less clear. Mean BMI increased over time within each five-year age group and in age 'cohorts' and the pattern was independent of smoking status. For men and for both groups of women there were similar changes in mean BMI over time for most categories of employment status, education and physical activity. Thus the increase in body weight cannot be explained by the decrease in smoking rate, or by the other factors investigated in this paper.