BACKGROUND

Obesity prevalence has continuously increased in Northern Sweden as elsewhere. A cohort effect has been shown and an increasing proportion of the middle-aged population is maintaining body weight.

OBJECTIVE

To test the hypothesis that the obesity epidemic continues but at different speeds that are dependent on socioeconomic status.

DESIGN

Cross-sectional (103,940 adults) and longitudinal (26,872 adults) data from the Västerbotten Intervention Program 1990-2007 were included. All adults in Västerbotten County are invited to a health examination at the ages of 40, 50, and 60 years. Body mass index (BMI) and socioeconomic status, assessed by residence location, marital status, and education were evaluated.

RESULTS

BMI increased in all groups but was greater among men. During 1990-1995 and 2002-2007, mean BMIs were 25.9 and 26.8 among men and 25.2 and 25.9 among women. The trend of increasing BMI slowed around the year 2000 (p<0.001), but this was only observed among the highly educated adults in the most urbanized area. The difference between educational groups increased throughout the study period (men p=0.014, women p=0.002). Longitudinal data for both sexes showed a twofold higher baseline prevalence of obesity among individuals with basic compared to high education and it nearly doubled in all groups during the 10-year follow-up. Low education, living in a rural environment, and living alone were independent predictors of obesity development. The overall cumulative 10-year incidence was 9.4% in men, 9.1% in women, and twofold higher among those with basic and mid-level education who live in rural areas compared to those with high education who live in cities.

CONCLUSION

The trend of increasing obesity has slowed in this middle-aged Northern Sweden population, but this trend shift occurred primarily among those with high education who live in an urban environment. Greater efforts to combat obesogenic environments are needed and should take socioeconomic and sociocultural aspects into account.