Trends in the prevalence of obesity among Belgian men at work, 1977-1992

To assess trends in average body mass index (BMI) and the prevalence of obesity between 1977 and 1992, in middle-aged Belgian men at work.

A subsample of men at work, aged 40-54 y extracted from the base-line data from four independent prospective studies, each representing a period (Physical Fitness Study (1977-1978), Belgian Interuniversity Research on Nutrition and Health (BIRNH) (1979-1984), Multinational Monitoring of Trends and Determinants in Cardiovascular Diseases (MONICA) (1986-1991) and ORCA (1992-1993)).

Linear regression of the average body mass index (kg/m2) and logistic regression of the prevalence of obesity (BMI > or = 30kg/m2). Independent variables taken into account in multivariate analysis were: age, educational level, marital status and region.

In this subsample of Belgian men at work, aged 40-54 y, prevalence of obesity increased from 9.2% in 1977-1978 to 14.5% in 1992-1993. This rise was present in each five-year age group, in both regions and in all educational groups, but strongest in the lowest educated. After adjustment for sociodemographic covariables, it was estimated that with regard to 1977-1978, the proportion of men with a BMI > or = 30 kg/m2 doubled over the 15-year period (odds ratio OR (95% confidence intervals, 95% CI)): 1.98 (1.40; 2.80).

Keeping in mind that the trends have been calculated from data from four different studies, presenting some shortcomings, prevalence of obesity has increased between 1977-1992 in men aged 40-54 y at work. This rise is particularly pronounced in the lower educated groups.