Improved living conditions affect lifestyles and may contribute to the increased prevalence of overweight and obesity among adolescents. The aim of the study was to analyze changes in the prevalence of underweight, overweight, obesity as well as excessive adiposity among teenagers from Kraków (Poland). The study was conducted in four series in the years: 1983, 2000, 2010, and 2020. The study group included 1759 boys and 1699 girls aged 16-18 years. body mass index (BMI) was calculated on the basis of body height and weight. Adiposity was measured by bioimpedance method. Participants were grouped according to BMI categories using Cole's cut-off points and according to adiposity based on mean and standard deviations values. The significance of the differences between cohorts was assessed by the Chi-square test. Secular increase in the prevalence of underweight and overweight was observed among girls in most age groups. An increase in the prevalence of high body fat was also observed among 16- and 17-year-old girls - the opposite trend was noted in 18-year-old girls. Contemporary boys had an increased prevalence of overweight and obesity in each age group. There was a significant increase in the prevalence of body weight abnormalities in the study population. The observed results may be related to socio-economic changes that adversely affect the lifestyle of the society. The results are also important in terms of the health of future generations and may be helpful in the development of new prevention and intervention programs.