Growth change in Polish women: Reduction of the secular trends?

The aim of the study was to analyse changes in the average height of adult Polish women born in 1931–2001 in the aspect of dynamically changing economic and socio-economic conditions of the living environment. An ethnically homogeneous group of 6,028 adult women from large Polish cities, born in 1931–2001, living between 1931 and 2020, were examined using the same research methods and research equipment. All women were divided into eight birth cohorts. The Kruskal-Wallis test and multiple regression analyses were used. Root Mean Square Standardized Effect (RMSSE), critical value of the test, and test power were calculated. The average height of women born during 70 years of the study increased by 9.63 cm, from 158.22 cm (SD = 5.57 cm) to 167.85 cm (SD = 6.91 cm) (H = 1084.84, p<0.001). The intensity of the intergenerational trend in subsequent cohorts of years of birth varied strongly between decades, averaging 1.34 cm/decade. The body height in women increased significantly up to the height of those born between 1970 and 1979 and then the trend weakened noticeably, although it remained positive. The observed secular trend confirms positive changes in the standard of living of Polish women between 1931 and 2020. Improving living conditions allow people to fully achieve their genetically determined growth potential.