Body height, body composition, and lifestyle of Czech high school students: implications for the most appropriate strategies supporting physical growth and preventing obesity.

Abstract

Background: This study summarizes anthropometric research that was conducted in two phases between 2015 and 2023. The aim of the first phase (2015-2016) was to map the current status of the height trend among adult high school students in the South Moravian region (the Brno-City District). The aim of the second phase (2016-2023) was to map the status of the height trend in three neighboring regions (Olomouc, Vysočina, Zlín) and to examine the relationship between body height, body composition, and some aspects of the students' lifestyle.

Methods: The study population consisted of 4655 individuals (2349 males, 2306 females) aged 18-22 from 71 high schools with a broad educational spectrum. The second phase of the research included 2045 individuals (1011 males, 1034 females) who completed questionnaires with questions about their lifestyle.

Results: Based on the measurements of body height in a sample of evenly stratified categories of high schools in the Brno-City District, we arrived at an average of 180.5 ± 6.8 cm in males (n = 1338) and 166.5 ± 6.3 cm in females (n = 1272) aged 18-20 years. The planned measurements of body height in the three remaining regions were not completed due to the COVID epidemic, but the total averages remained practically unchanged (180.3 ± 6.8 cm in males, n = 2326; 166.5 ± 6.4 cm in females, n = 2299). An analysis using linear mixed-effect models showed that body height was best predicted by dairy consumption in males and by school lunch attendance in females. Low % body fat was most strongly associated with physical activity, distantly followed by high parental education and daily school lunch attendance. In both sexes, height was inversely related to % body fat, but this relationship was not mediated by physical activity.

Conclusions: Taking into account other available data, it can be concluded that the secular trend of body height in the Czech Republic probably continues very slowly in males but stagnates in females. The inverse relationship between height and % body fat has an analogy in many other developed countries and suggests that a diet based on high-quality animal proteins should be the most effective strategy for supporting optimal physical development and preventing child obesity.