Within the framework of the first risk factor survey among the two reporting units of MONICA-Switzerland (cantons of Vaud and Fribourg; canton of Tessin), body mass index (BMI) was also analysed. One in four adults (25-74 years) presents with overweight, this proportion being even 1 in 3 among males of the canton of Tessin. However, this health risk can probably be changed, as every third female and every fifth male indicated to have modified their nutritional habits in a more healthy sense within the last 12 months preceeding the survey. On the other side, less than half of the population engages in a degree of physical activity conducive to cardiovascular prevention and reduction of overweight. In order to increase the level of physical activity in the population, it is primarily leisure time sports activities that have to be developed as only very few adults experience a heavy physical work load within their profession.