Increasing prevalence of overweight, obesity and physical inactivity: two population-based studies 1986 and 1994

The aim of this study was to investigate the 1986-1994 trend in obesity, overweight and sedentary leisure-time physical activity status, and the educational gradient in overweight and obesity in the city of Malmö, Sweden.

The public health surveys in Malmö 1986 and 1994 are cross-sectional studies. A total of 4,800 and 5,600 individuals aged 20-80 years were randomly chosen to be interviewed by a postal questionnaire. The participation rates were 74% and 71%. Obesity was defined as BMI 30.0 or more and overweight as BMI 25.0-29.9. The prevalences of leisure-time physical inactivity, obesity and overweight were computed, and the differences between 1986 and 1994 as well as educational gradients in overweight and obesity were assessed.

The prevalence of obesity increased from 4.6% to 11.4% (p<0.001) among men and from 6.1% to 9.8% (p<0.001) among women. The prevalence of overweight (BMI 25.0-29.9) increased from 33.9% to 45.2% (p<0.001) among men, and from 19.6% to 29.1% (p<0.001) among women. The prevalence of leisure time physical inactivity increased among men from 14.7% to 18.1% (p<0.001) among men and from 19.4% to 26.7% (p<0.001) among women. The increasing prevalences of obesity, overweight and physical inactivity were observed in all age, country of origin and educational status groups. The educational differences in BMI 25.0+ observed among both men and women in 1986 disappeared among men in 1994. In contrast, educational differences in obesity (BMI 30.0+), not seen in 1986, appeared in 1994 among men.

The proportions of the population with obesity and overweight increased significantly between 1986 and 1994 for both men and women. The increasing prevalence of physical inactivity seems to be an important explanation.