Social mapping of the obesity epidemic in Sweden

OBJECTIVE: The aim of the present study is to describe the evolution of the obesity epidemic in Sweden, with specific attention to the socioeconomic gradient. DESIGN: Data from the Swedish Surveys of Living Conditions were used. Three such surveys were undertaken in 1980/81, 1988/89, and 1996/97, each of which was based on a simple random sample from the national population registry. SUBJECTS: A total of 38,284 observations are used in this analysis, including males and females aged 16-84. The sample is approximately equally divided among the 3 survey periods and by gender. MEASUREMENTS: The following body weight categories are used to describe changing prevalences: overweight (BMI greater than or equal to 25), obesity (BMI greater than or equal to 30) and underweight (BMI < 18.5). Because body weight and heights were self-reported, recorded values were adjusted for estimating gender-specific obesity prevalences, Education was used as a proxy for socioeconomic status. RESULTS AND CONCLUSIONS: The prevalence of BMI greater than or equal to 30 increased significantly over the 16-year observation period. At the time of the 1980/81 survey, the adjusted estimates were 8.8% in women and 6.6% in men, compared to 11.9% and 10.0% respectively, in 1996/97. The prevalence of BMI greater than or equal to 25 was also analyzed for time trends, with specific attention to populations at risk. The largest proportionate changes occurred in women aged 16 - 44, among whom the prevalence of overweight doubled. The inverse educational gradient with respect to obesity is still present in both sexes, but there is no indication that it has increased in magnitude between 1989/81-1996/97.