Objective: Whether differences in obesity prevalences across social status levels have widened remains controversial.
Methods: We used German national health surveys (1990-1992 and 1998, n = 7,466 and 5,583, age 25-69 years) to estimate obesity prevalences and its associations with calendar year, age (25-39, 40-60, and 61-69), and educational level (low, middle, and high), as well as an interaction term (year x educational level) in men and women. We used multiple regression models, considering the sample design.
Results: Obesity prevalence in 1990 and 1998 was 18.1 (95% CI 16.5-19.7) and 19.9 (18.2-21.6) in men and 20.9 (19.2-22.6) and 21.6 (19.3-23.7) in women, with statistically significantly higher prevalences in higher age and lower education. A statistically significant increase of obesity prevalence was present only in men after adjustment for age and education. The increase seems to be highest in high-educated subjects. However, interaction was not statistically significant, except in middle compared to high-educated men (OR 0.67; 0.47-0.96).
Conclusions: Obesity prevalence increased only moderately in Germany between 1990-1992 and 1998. There was a tendency of reduction of the social gradient in obesity instead of a widening.