Changes in the prevalence of overweight and obesity: some evidence from the Swiss Health Surveys 1992/93 and 2002.

BACKGROUND This study examines changes in the prevalence of overweight and obesity in the Swiss general population from 1992/93 to 2002 and their relationship with changes in the distribution and effect of socioeconomic and health behavioural risk factors. METHODS Cross-sectional data from telephone interviews of the non-institutionalized Swiss population aged 19 years and more were obtained from the Swiss Health Study 1992/93 (n = 13798) and 2002 (n = 17677). Binary logistic regression was used to address changes in overweight and obesity, defined as body mass index 25.0 kg/m(2) or more. The expected prevalence of overweight and obesity under adjusted models was computed to demonstrate the influence of changes in risk factors. RESULTS The prevalence of overweight and obesity rose from 22.8% in 1992/93 to 30.9% in 2002 among women and from 41.1% to 48.1% among men. In international comparison, the increase in the overall prevalence of overweight and obesity in Switzerland was lower. Contrary to similar studies from other countries, the increase in prevalence was lower among men than that among women, possibly because of an increased protective effect of the observed health behavioural factors among men and unobserved behavioural factors among middle-aged men. CONCLUSION Public health action should consider the potential of changing health behavioural factors in subgroups with a higher prevalence of overweight and obesity. Measures that stimulate, for instance, light physical activity or healthy diet, to be supported by changes in the obesogenic environment, should be encouraged. More evidence is needed for gender-specific approaches.