The BMI data of four birth cohorts of totally 180,716 male 18 year old Austrian conscripts were documented in 5 year intervals starting 1985 and ending 2000 in order to analyze regional and social variety and a time trend of stature, body weight and BMI as well as the prevalence rates of overweight (defined as a BMI > 25.00) and obesity (BMI > 30.00). At first a marked time trend in BMI and overweight /obesity prevalence rates was found. Over the 15 years of investigation BMI increased significantly and the variation of BMI distribution increased too. The impact of educational level on BMI and the prevalence of overweight and obesity was also statistically significant. With increasing educational level BMI and the prevalence rates of overweight and obesity decreased significantly. Furthermore a significant regional variety in BMI and the prevalence rates of overweight and obesity were found. BMI and the prevalence rates of obesity and overweight decreased significantly from the Eastern part of Austria to the Western part. Both observations, e.g. the social and regional variety of obesity and overweight prevalence, were true of all 4 birth cohorts. From these results we can conclude that obesity and overweight represent an increasing health problem among young Austrian males. This is especially true of young men of low social status living in the eastern part of Austria.