Objective: To describe long-term and recent time trends in the prevalence of obesity by age and educational level.
Design: :Repeated cross-sectional population based monitoring studies.
Setting: Consultation Bureau Heart Project 1976-1980, Monitoring Project on Cardiovascular Diseases 1987-1991 and Monitoring project on risk factors for chronic diseases (MORGEN-) project 1993-1997.
Subjects: A total of 29 141 men and women aged 37-43 y (1976-1997); and 21 926 men and women aged 20-59 y (1993-1997).
Measurements: Body mass index, ie weight divided by height squared.
Results: Between 1976 and 1997 the prevalence of obesity increased from 4.9 to 8.5% among men and from 6.2 to 9.3% among women aged 37-43 y. Between 1993 and 1997, the prevalence of obesity among men aged 20-59 y was 8.5% and increased by 0.54 percentage points per year (P<0.01). The prevalence of obesity among women was 9.6% and increased by 0.35 percentage points per year (P=0.07). The increase in the prevalence of obesity in the period 1993-1997 was strongest in men with a relatively low educational level and in women with a high educational level.
Conclusions: There has been a steady increase in the prevalence of obesity in the last quarter of the 20th century. Also, a recent increase in the prevalence of obesity has been seen. To stop the increase in the prevalence of obesity, effective strategies for the management and prevention of obesity need to be developed.