Background: The co-occurrence of obesity and elevated blood pressure (EBP) in childhood represents a critical but underrecognized public health concern, with potential long-term consequences for cardiometabolic health. Understanding its trends and disparities is essential for early prevention strategies. Methods: This study analyzed data from 1,692,660 Han Chinese children and adolescents aged 7–18 years collected across seven waves of the Chinese National Survey on Students’ Constitution and Health (CNSSCH) from 1985 to 2019. Joinpoint regression was used to estimate temporal trends, and logistic generalized additive models were fitted to predict prevalence through 2030. Results: The prevalence of co-occurring obesity and EBP increased from 0.06% in 1985 to 2.36% in 2019 and is projected to reach 5.87% by 2030. A slowdown in the growth rate was observed approximately in 2000. Notably, rural areas experienced a faster and more recent rise, especially among girls, suggesting widening disparities. Conclusions: The growing dual burden of obesity and EBP in Chinese youth, especially in rural areas, calls for urgent and integrated interventions. Public health efforts must prioritize early prevention, with equitable policies that engage schools, families, and communities, particularly in underserved populations.

Background: The rising prevalence of childhood overweight/obesity (OWOB) and elevated blood pressure (EBP) parallels a global decline in muscular fitness. However, evidence linking whole-body muscular strength to the comorbidity of these cardiometabolic risks remains scarce. Methods: Data were obtained from five nationally representative waves of the Chinese National Survey on Students’ Constitution and Health (CNSSCH, 2000–2019), including 1,072,404 children and adolescents aged 7–18 years. A novel Muscle Strength Index (MSI) was developed by integrating handgrip strength (HGS) and standing broad jump (SBJ), standardized for body weight and height, respectively. Generalized linear mixed-effects models (GLMMs) with restricted cubic splines (RCS) were first applied to characterize dose–response associations. Subsequently, categorical analyses and forest plots were conducted to quantify risks of OWOB, EBP, and their comorbidity across five waves and subgroups. Sex-specific normative reference curves were established using the LMS method, and population-attributable fractions (PAFs) were estimated to assess the potential public health benefits of improving muscular strength. Results: Between 2000 and 2019, the prevalence of OWOB, EBP, and comorbidity increased markedly, reaching 25.80%, 12.23%, and 4.83% in 2019, and are projected to rise further to 37.88%, 20.16%, and 10.01% by 2030. Over the same period, mean MSI increased from 2000, peaked in 2005, and subsequently declined by 2019 with the values for boys and girls, being 1.73, 1.75, 1.63 and 1.46, 1.49, 1.41, respectively. Dose–response analyses revealed consistent L-shaped associations, with the greatest risk reductions observed when moving from low to moderate MSI levels. In 2019, participants with low MSI had higher odds of OWOB (OR 4.81, 95% CI 4.65–4.97), EBP (OR 1.42, 95% CI 1.36–1.49), and comorbidity (OR 3.49 95% CI 3.26–3.73) compared with those at middle levels. PAF analyses indicated that improving MSI to at least the 40th percentile could potentially avert 43.5% of OWOB cases, 12.3% of EBP cases, and 48.2% of comorbidity cases. The highest potential benefits were observed in northern and northeastern provinces, particularly Tianjin and Heilongjiang. Conclusions: Chinese children and adolescents face a dual burden of rising cardiometabolic comorbidity and declining muscular strength. Muscular strength demonstrates a strong nonlinear protective association with OWOB, EBP, and their co-occurrence. Targeted improvement among those with low muscular strength may substantially reduce future cardiometabolic burden.

Objectives: This study aimed to explore whether the association of lifestyle behaviors with mental well-being differed by sports app use among college students, while also examining differences by sex. Methods: A total of 38,738 Chinese college students aged 19–22 years from a nationally cross-sectional survey in 2019 were included in this study. The Warwick Edinburgh Mental Wellbeing Scale was applied to evaluate mental well-being. Clustered lifestyle behaviors were defined as unfavorable (zero to two healthy factors), intermediate (three healthy factors), or favorable (four to five healthy factors). The use of sports apps was classified as dichotomized frequently (sometimes and often) and infrequently (never, rarely, and occasionally). Log-binomial regression was used to investigate the associations. Results: Intermediate (PR = 1.14, 95% CI: 1.11–1.18) and unfavorable (PR = 1.29, 95% CI: 1.26–1.33) lifestyles were positively associated with low mental well-being. Infrequently using sports apps was associated with low mental well-being (PR = 1.08, 95% CI: 1.06–1.10). The magnitude of the association between an unfavorable lifestyle and low mental well-being was smaller among girls who frequently used sports apps (PR = 1.22, 95% CI: 1.16–1.27) than among those who used them infrequently (PR = 1.31, 95% CI: 1.24–1.38). Conclusion: These findings suggest that integrating engagement with digital sports apps into campus health promotion strategies might help support mental well-being, especially for college students with multiple unhealthy lifestyle behaviors.