Many studies have shown smokers to weigh less than non-smokers, which is plausible given the metabolic effects of cigarette smoke. The interrelation between smoking and relative body weight and its change over time were analysed by using data from Finnish population based surveys from 1982 and 1987. Among both men and women the inverse association between smoking and body mass index was clearly weakened between 1982 and 1987. In 1987 among men aged 25-44 smoking was positively related to body mass index. Moreover, the relation between smoking and waist to hip girth ratio was positive in both sexes at all ages. Years of smoking was nevertheless confirmed as a significant inverse predictor of relative weight. A cluster of unfavourable health habits, including high consumption of alcohol and saturated fats, especially emerged among younger smokers. This may have been due to different selection of smokers in Finland, where smoking increasingly seems to be a form of deviant or risk taking behaviour. It is concluded that at a population level the metabolic effects of smoking seem to be increasingly overridden by several other unfavourable health behaviours of smokers.