BackgroundThis study examined a) trends in overweight/obesity, moderate-to-vigorous physical activity (MVPA), and screen time (ST) among Czech adolescents over a 12-year study period (2002–2014) in relation to family affluence (FA) and b) correlates of adolescent overweight/obesity from different FA categories.MethodsA nationally representative sample of 18,250 adolescents (51.4% girls) aged 10.5–16.5 years was drawn from the Czech Health Behaviour in School-aged Children questionnaire-based surveys in 2002, 2006, 2010, and 2014. Using the FA scale, the socioeconomic status (SES) of the respondents’ families was assessed. SES-stratified trends in the prevalence of overweight/obesity meeting the MVPA (≥60 min/day), and ST (≤2 h/day) recommendations were assessed using logistic regression.ResultsA trend-related significant increase (p < 0.05) in the prevalence of overweight/obesity was observed in low−/medium-FA boys and medium−/high-FA girls. Unlike in high-FA adolescents, a significant decrease was revealed in the rates of meeting the MVPA recommendation in low-FA boys (28.9%2002 → 23.3%2014, OR = 0.75, 95% CI = 0.59–0.95, p < 0.05) and girls (22.3%2002 → 17.3%2014, OR = 0.73, 95% CI = 0.57–0.92, p < 0.01). A significant (p < 0.001) trend-related increase in excessive ST was evident in adolescents regardless of gender and FA category. Generally, girls and older adolescents had lower odds of overweight/obesity than boys and 11-year-old adolescents. While in the high-FA category of adolescents, achieving 60 min of MVPA daily and the absence of excessive ST on weekdays significantly (p < 0.01) reduced their odds of being overweight/obese, in low-FA adolescents this was not the case.ConclusionsHigh rates of overweight/obesity and a poor level of daily MVPA among low-FA children provide disturbing evidence highlighting the necessity of public health efforts to implement obesity reduction interventions for this disadvantaged population.

Socioeconomic inequalities in eating habits have a profound impact on the health of adolescents. The aim of the present study was to evaluate socioeconomic disparities in the eating habits of Czech adolescents and to compare their change between 2002 and 2014. The data from the Czech Health Behavior in School-aged Children (HBSC) study conducted in 2002 and 2014 was utilized. The Family Affluence Scale (FAS) was used to assess socioeconomic disparities. Higher odds of daily consumption of fruit (2002: OR = 1.67; 2014: OR = 1.70, p < 0.001) and vegetables (2002: OR = 1.54; 2014: OR = 1.48, p < 0.001) were associated with high FAS in both genders. Adolescents with higher FAS were less likely to consume sweets (2002: OR = 0.72, p < 0.05) and more likely to eat breakfast on weekdays (2014: OR = 1.19, p < 0.05). In 2002 and 2014, the data showed lower odds of daily consumption of soft drinks (Low: OR = 0.47; Medium: OR = 0.43; High: OR = 0.41, p < 0.001), fruit (Low: OR = 0.73; Medium: OR = 0.74, p < 0.001; High: OR = 0.75, p < 0.05), sweets (Low: OR = 0.71; Medium: OR = 0.79, p < 0.001) and breakfast on weekends (High: OR = 0.70, p < 0.05), and a higher likelihood of eating breakfast on weekdays (Low: OR = 1.26, p < 0.01; Medium: OR = 1.13, p < 0.05). These findings play an important role in future public measures to improve dietary habits and decrease social inequalities in youth.

Background: The main objective of the study is to analyse the changes in the prevalence of obesity among Czech adolescents between 2002 and 2018 with regard to the socioeconomic status (SES) of adolescents' families and to find SES-separated correlates of adolescents' obesity in 2018. Methods: A nationally representative sample of 29,879 adolescents (49.6% of them boys) aged 10.5-16.5 years was drawn from the Health Behaviour in School-aged Children cross-sectional, self-reported questionnaire surveys conducted in 2002, 2006, 2010, 2014, and 2018 in Czechia. Chi-square (χ 2) tests were performed to assess the changes in the prevalence of obesity in both genders and all SES categories of adolescents between 2002 and 2018, and SES category-related differences in the prevalence of obesity in 2018 separately for boys and girls. A series of multiple stepwise logistic regression (backward elimination) analyses were used to reveal obesity correlates separately for SES categories of adolescents. Results: Across the quadrennial surveys from 2002 to 2018, we observed a clear increase in the prevalence of obesity in all SES categories of adolescents, which was most striking (p < 0.05) in adolescents with low SES (boys: + 7.5% points (p.p.); girls + 2.4 p.p.). When all the survey cycles were compared, the highest prevalence of obesity was evident in the low-SES adolescents in 2018, both in girls (5.1%) and boys (12.0%). Regardless of the adolescent SES category, the lower odds of obesity were significantly (p < 0.05) associated with regular vigorous physical activity (PA), participation in organized sport, and daily consumption of sweets. In addition, at least 60 min of moderate-tovigorous PA significantly reduced the odds of obesity in adolescents of low and high SES categories. Conclusions: An unreasonable increase in the prevalence of obesity in adolescents with low SES highlights the need to prevent obesity in adolescents with a low-SES background. Additionally, significantly higher odds of obesity in 11-and 13-year-old adolescents from low-SES families, compared with their peers aged 15, indicated an expectable rise in obesity in older low-SES adolescents in the near future.

Participation in OLTA was associated with healthier eating habits (e.g., consumption of fruit and vegetables) and a lower occurrence of unhealthy eating habits (e.g., consumption of soft drinks). Alternatively, our findings indicate that non-participation in OLTA can serve as an indicator of an unhealthy lifestyle in adolescence. What is Known • Unhealthy eating habits in youth tend to persist into adulthood and are related to adverse health consequences later in life. • The type of the leisure-time activity (participation in sport, non-sport, sport, and other activities) affects the strength of developmental outcomes in adolescents. What is New • Youth participating in non-sport activity and sport and other activity concurrently reported lower rates of unhealthy eating habits (e.g., eating junk food, eating in front of the TV/computer). • Non-participation in OLTA could be viewed as a potential risk factor for an unhealthy lifestyle in adolescents.

This study reveals a quantifiable relationship between parent-child SC/day and mothers' ST and children's SC at weekends. Weekend days are more suitable for the implementation of family-based interventions.