Sweden, the country hosting this year's European Obesity Summit in Gothenburg (1-4 June) has always been associated with good health indicators. However new research presented at the summit shows that obesity has continued to increase across mid-Sweden since the start of the new millennium. The study is by Dr Anu Molarius, Competence Centre for Health, Västmanland County Council, Västerås, Sweden, and colleagues.
The area studied includes four counties with about one million inhabitants. It does not include any big cities such as Stockholm or Gothenburg but several smaller cities such as Uppsala (with about 200 000 inhabitants), and Västerås and Örebro (with about 140 000 inhabitants each).
The simple aim of this new research was to investigate trends in the prevalence of obesity by age and level of education in the general population in mid-Sweden from year 2000 to 2012. A postal questionnaire was sent to a random population sample aged 25-74 years in years 2000, 2004, 2008 and 2012. The overall response rates were 67%, 65%, 60% and 53%, respectively, and the study included 29017, 27385, 25910 and 24152 respondents, respectively. Obesity (BMI of over 30 kg/m2) was based on self-reported weight and height.
The researchers found that age-standardised prevalence of obesity increased from 13% to 17% in women and from 12% to 17% in men between 2000 and 2012. Obesity increased in all age groups from 2000 to 2008 and continued to increase among the middle aged (45-64 years) between 2008 and 2012. (see table below)
The socioeconomic gradient in obesity changed during the study period since the absolute increase in obesity was steepest at the middle educational level. In 2012, the prevalence of obesity was almost twice as high at both middle and low educational levels compared with high educational level. After making corrections to the data to adjust for potential errors in self-reported weight and height, the researchers estimated the "true" prevalence of adult obesity to be approximately 20% in 2012 for both men and women.
Dr Molarius says: "Obesity has continued to increase in the general population, but the increase among people of mid-educational level appears to have been the most rapid."
She adds: "The prevalence is about 2 percentage points higher in this area we studied than in national studies, where the population is more concentrated in big cities which have a lower prevalence of obesity in general. But we think that similar trends over time are probable. To verify this, however, national studies are needed."
"While obesity may be slowing down in some groups, it is not in the majority. The continuing increase among the middle-aged and among those with a middle level education, who represent half of the adult population, is a major public health challenge."