Physical Activity, Screen-Based Sedentary Behavior and Physical Fitness in Chinese Adolescents: A Cross-Sectional Study

Determinants of childhood obesity in China

Over the past four decades, China has witnessed an important nutritional transition, characterised by a heightened overnutrition burden among children. The country now has the largest population of children with obesity globally. In this paper, we review the epidemiology of childhood obesity in China, its determinants, and risk factors, with a particular focus on school-aged children. Evidence unveils substantial variations across age, gender, and region. We describe multilevel obesogenic determinants, including macro-level social, cultural, and environmental factors; meso-level factors related to schools and communities; and micro-level factors tied to families and individuals from the perinatal-infant stage to childhood and adolescence. The primary drivers of childhood obesity appear to be rooted in the broader macro-level social, economic, and technological environment; obesogenic factors, which have affected school, community, and family environments; and accelerated unhealthy behaviour uptake. Identifying and characterising the catalysts behind the rise in childhood obesity in China is imperative for the development of scalable, effective, and tailored prevention, control, and intervention strategies.

Associations of perceived neighbourhood and home environments with sedentary behaviour among adolescents in 14 countries: the IPEN adolescent cross sectional observational study

BACKGROUND

Understanding environmental correlates of sedentary behaviour (SB) among young people is important as such data can identify approaches to limit sedentary time. This paper estimates associations of parent-reported neighbourhood and adolescent-reported home environments with SB among adolescents aged 11-19 years from 14 countries.

METHODS

In the International Physical activity and the Environment Network (IPEN) Adolescent Study (an observational, cross-sectional multi-country study), adolescents wore a triaxial accelerometer for seven days that assessed sedentary time (ST). Adolescents completed survey measures of sedentary behaviour (SB) related to recreational screen time and sitting time in motor vehicles. Parents and adolescents completed surveys assessing neighbourhood and home environments. Accelerometer based ST was available in 3,982 adolescents while survey data were available for 6,302 dyads. We estimated the total and direct effects of each environmental attribute on ST and SB. Sex of the adolescent and city/country were examined as moderators.

RESULTS

The average ST in adolescents from 14 countries ranged from 7.8 to 10.5 h/day. Personal social media was the only significant correlate of total ST across both sexes. With respect to self-reported SB, adolescents accumulated an average of 3.8 h of non-school screen time per day and nearly 40 min of transport-related sitting time. Screen time was associated with all home environment variables, including social media account, as well as land use mix-diversity, traffic safety, and crime safety. Transport-related sitting time was related to land use mix-diversity, recreation facilities, walking facilities, and pedestrian infrastructure, but no home environment variables. City/country and sex were significant moderators of several associations.

CONCLUSIONS

Both home and neighbourhood environment features were related to ST and SB. Having social media accounts emerged as a major contributor towards sedentarism in adolescents.

The Chinese version of the physical activity questionnaire for adolescents: a psychometric validity, reliability, and invariance study

BACKGROUND

The Physical Activity Questionnaire for Adolescents (PAQ-A) is one of the most commonly used questionnaires for assessing adolescents' levels of moderate to vigorous physical activity (PA). Although a Chinese version of the PAQ-A (comprising nine items) exists, it has been assessed for only internal consistency coefficients, test-retest reliability, and correlations with the GT3X + accelerometer. Therefore, this study aimed to evaluate the psychometric properties of the Chinese version of the PAQ-A among Chinese adolescents.

METHODS

This study included three samples of 1,101 secondary school students (12-19 years old). The first sample consisted of 518 participants (50.4% males, 49.6% females) for correlation tests and exploratory factor analysis (EFA). The second sample consisted of 227 participants (55.75% males, 44.24% females) for confirmatory factor analysis (CFA), convergent validity, and sample size invariance tests. The third sample consisted of 356 participants (54.50% male, 45.50% female) for the internal consistency reliability test, invariance test (cross sample size, education level and gender), and t-test.

RESULTS

Pearson correlation analysis of the PAQ-A indicated that all the total-item correlations exceeded 0.2, indicating good consistency across the items. Subsequent EFA of the Chinese version of the PAQ-A revealed a two-factor structure. CFA subsequently validated this structure. One of the items exhibited a standardized loading below 0.4 and was excluded. The exclusion of this item resulted in increased standardized loadings for the remaining items, ranging from 0.40 to 0.82, which indicates improved fit indices. This adjustment underscores the questionnaire's satisfactory convergent validity and robust discriminant validity. The overall Cronbach's alpha was 0.821, with the values for the first and second factors being 0.757 and 0.716, respectively. The questionnaire demonstrated stable invariance across sample sizes and education levels and additionally showed partial scalar invariance across genders. A t-test revealed a significant difference between males and females, which aligns with previous findings. These findings supported the construct validity of the questionnaire.

CONCLUSION

This study validated the Chinese version of the PAQ-A for assessing adolescent PA in China, with a two-factor structure improved by removing one item.

Prevalence and lifestyle determinants of depressive symptoms among Chinese children and adolescents

Based on Chinese Students' Fitness Health Examination, this study sought to investigate the relationships between depressive symptoms and family environment, physical activity, dietary habits, sleep and sedentary behavior among children and adolescents. A cross-sectional study was carried out to estimate the prevalence of depressive symptoms in 32,389 participants (grades 4-12) using the CES-D. Logistic regression was used to evaluate the relationships between lifestyle determinants and depressive symptoms, and a random forest model was used to rank the importance of those determinants. The overall prevalence of depressive symptoms was 39.93%. Students with depressive symptoms had higher grades, lower parental educational levels and unhealthy lifestyles (P < 0.05). The top ten most important determinants of depressive symptoms were grade, egg intake, milk/soy product intake, frequency of muscle strength training, screen time, sleep duration, parental educational level, sugar beverage intake and total physical activity. Socioeconomic status, physical activity, sleep and screen time, and diet habits are determinants of depressive symptoms, and surveillance of lifestyles may be an effective way to detect students with depressive symptoms early.

An experimental study on the influence of healthy physical education curriculum model on sports ability of Chinese senior high school students

In recent years, the growing incidence of health issues among Chinese students, including obesity, diabetes, and other chronic diseases, has been attributed to a sedentary lifestyle, lack of physical activity, and unhealthy eating habits. Physical education (PE) classes play a crucial role in promoting physical activity and fostering healthy lifestyles among Chinese students. The purpose of this study was to investigate the influence of the healthy PE curriculum model on the sports ability of senior high school students in China. The trial adopted a quasi-experimental design with equivalent groups. The experimental group followed the healthy PE curriculum model in their PE classes, while the control group received traditional technical instruction. During the 12-week intervention, 149 senior high school students completed the sports ability test as both the pre-test and post-test measurements for this experimental study. The results indicated that the experimental group showed significant improvements in sports ability compared to the control group, highlighting the positive effects of the healthy PE curriculum model. The structural characteristics of the healthy PE curriculum model provided essential support for students' learning and proved to be an effective way to promote physical literacy among senior high school students in China.

Impact of home quarantine on physical fitness of school-aged children in Xi'an during COVID-19 lockdown: a cross-sectional study

BACKGROUND

The emergence of the COVID-19 pandemic has sparked unprecedented global challenges. This study intends to investigate changes in the physical fitness of students aged 6-22 during the COVID-19 pandemic and to assess how the pandemic lockdown period affected these markers.

METHODS

According to the National Student Physical Health Standard, a stratified cluster sampling method was used to evaluate the body shape, body function, and physical fitness of children and adolescents (n = 8092) in Xi'an from 2019 to 2021. This study uses SPSS 26.0 (IBM, Chicago, IL, USA) for data statistics and analysis. The connection between physical fitness and years was measured using the one-variable analysis in the general linear model (GLM). Independent t-tests were used to determine the sex (male/female) and area (urban/rural) differences.

RESULTS

During the lockdown period, Body Mass Index (BMI) and flexibility showed an upward trend, while aerobic, strength, speed, and endurance showed a downward trend. In addition to the BMI of middle and high school students, almost all indicators show significant sex differences. There are urban-rural differences in some indicators, such as chin-ups.

CONCLUSION

During the pandemic of COVID-19, the physical fitness of children and adolescents in Xi'an did not change significantly, and there were slight differences among different grades. During the pandemic lockdown period, lifestyle changes and reduced outdoor activities for children and adolescents may be the reasons for the changing trend of various indicators.

Nutrition literacy status and its association with adherence to the Mediterranean diet, anthropometric parameters and lifestyle behaviours among early adolescents

OBJECTIVE

To evaluate nutrition literacy status and its association with adherence to the Mediterranean diet (MD), anthropometric parameters and lifestyle behaviours among early adolescents.

DESIGN

This is a cross-sectional study. Nutrition literacy was evaluated using the 'Adolescent Nutrition Literacy Scale'. Dietary intake was assessed by 24-h food recall. The 'Mediterranean Diet Quality Index' was used to evaluate adolescents' adherence to the MD. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ). Body weight, height, waist, hip and neck circumference were measured.

SETTING

Four secondary schools in İzmir, Türkiye.

PARTICIPANTS

The study included 1074 secondary school students.

RESULTS

Adolescents' nutrition literacy was at a moderate level. Nutrition literacy scores were significantly lower in those who skip main meals. Adolescents with high nutrition literacy had higher intakes of fibre, protein, protein, Ca, K, Mg, P, vitamin C, folate and Fe intake than those with low and moderate nutrition literacy (P < 0·05). According to IPAQ, active adolescents had higher nutrition literacy scores than inactive adolescents. There was no significant difference in BMI and anthropometric measurements of the adolescents according to their nutrition literacy level. Linear regression analysis showed that each unit increase in nutrition literacy increased adherence to the MD by 0·286 points (β = 0·286) and decreased total screen time by 0·182 points (β = -0·182).

CONCLUSIONS

These findings showed that nutrition literacy among early adolescents was not optimal, and a higher nutrition literacy score was significantly associated with higher MD adherence, and healthy eating habits and lifestyle behaviours.

Associations of multiple sleep dimensions with overall and abdominal obesity among children and adolescents: a population-based cross-sectional study

BACKGROUND

The relationship of insufficient sleep with the increased risk of obesity has been reported, but less is known about other sleep dimensions in the sleep-obesity associations.

OBJECTIVES

To assess the associations of multiple sleep dimensions with overall and abdominal obesity among Chinese students.

METHODS

This was a cross-sectional study involving 10,686 Han students aged 9-18 from Chinese National Survey on Students' Constitution and Health (CNSSCH). We collected sex, age, regions, parental educational levels, physical activity duration and sleep-related information by questionnaire survey, and also conducted anthropometric measurements including height, weight and waist circumference (WC). Unadjusted and adjusted binary logistic regression models were used to estimate the associations of sleep-related dimensions with obesity-related indicators.

RESULTS

Short sleep duration was associated with higher body mass index (BMI), larger WC and higher waist-to-height ratio (WHtR) in 9-12 and 16-18 age groups, whereas prolonged sleep duration on weekday was associated with higher BMI in 13-15 age group. Non-habitual midday napping and midday napping ≤0.5 h/d (vs 0.5 to 1 h/d) increased the risk of higher BMI in 13-15 age group, and the former was also associated with larger WC in 9-12 age group. Late bedtime was associated with larger WC and higher WHtR in 9-12 age group and with higher BMI and WHtR in 13-15 age group. Students aged 9-12 with social jet lag ≥2 h were found to have greater BMI after adjustment (Odds Ratio: 1.421; 95% confidence interval: 1.066-1.894).

CONCLUSIONS

Short or overlong sleep duration, late bedtime and great social jet lag were associated with higher prevalence of overall or abdominal obesity, while moderate midday napping can effectively decrease the risk. Those findings may assist in developing preventive strategies to combat obesity epidemic.

Secular trends in physical fitness of rural Chinese children and adolescents aged 7-18 years from 1985 to 2019

The main purpose of the study was to evaluate the secular trends in physical fitness of Chinese rural children and adolescents aged 7-18 from 1985 to 2019. The speed, muscular strength, explosive power fitness, cardiorespiratory fitness, and flexibility were investigated by National Survey on Students' Constitution and Health in 1985, 2000, 2010 and 2019. During the period 1985-2000, the physical fitness of Chinese rural children and adolescents improved except for flexibility, and almost all of them reached the maximum increase rate. During the period 2000-2010, in addition to the improvement of flexibility, other fitness showed downward trends, and the decline ranges were large. During the period 2010-2019, the speed of boys rebounded, flexibility, explosive power and muscular strength continued to decrease. Meanwhile, speed, flexibility and muscular strength in girls rebounded, and the explosive power continued to decline. From 2000 to 2019, the body mass index increase accelerated. This study shows that some components of physical fitness of Chinese rural children and adolescents have shown positive trends in recent years, especially for girls and adolescents aged 13-15 years. However, it may also imply inequality between sexes and ages, which provides a reference for the focus of the country's physical fitness and health monitoring and intervention measures.

Associations between socioeconomic status and risk of obesity and overweight among Chinese children and adolescents

BACKGROUND

In China, the threat of obesity and overweight in children and adolescents is developing quickly. It may be possible to lower the risk of obesity and overweight in children and adolescents by understanding the factors that drive these conditions. Therefore, this study aimed to investigate the association between SES and risk of obesity and overweight among children and adolesecnts in China's provinces of Jiangsu, Anhui, Zhejiang, and Shanghai.

METHODS

Chinese children and adolescents (n = 2,746; 46.3% boys) were recruited using multistage sampling. SES was measured using self-reported questionnaires, the specific indicators were parental education, perceived family wealth, and Family Affluence Scale II. Height and weight were measured and used to calculate body mass index (BMI, categorized into obesity or overweight). The definition of obesity or overweight was based on the Chinese standard "Screening for obesity and overweight among school-age children and adolescents". Descriptive statistics, independent sample t-tests, and a Chi-square test were used to report the sample characteristics and analyse BMI differences across different sociodemographic groups. A binary logistic regression was then applied to analyse the association of SES indicators with BMI in children and adolescents.

RESULTS

Overall, 22.5% of children and adolescents were obese or overweight. Participants with medium and high maternal education levels were 1.48 [95% CI 1.15-1.91] and 1.47 [95% CI 1.03-2.11] times more likely to be obese/overweight. Girls with medium maternal education levels were 1.70[95% CI 1.21-2.40] times more likely to be obese/overweight. For boys, no association was observed. Junior middle school students with medium maternal education levels were 1.51[95% CI 1.10-2.07] times more likely to be obese/overweight. Participants with medium or high FAS, perceived family wealth, or paternal education levels were not associated with obesity/overweight.

CONCLUSIONS

The findings of this study indicated a positive association between SES and risk of overweight/obesity in girls, suggesting that maternal education level may have a substantial impact on future prevention efforts for these conditions in girls. To increase the effectiveness of interventions, longitudinal studies are necessary to better understand the causal association between SES and obesity/overweight.

Association between physical activity, sedentary time, and physical fitness of female college students in China

BACKGROUND

Prior research has highlighted the importance of Physical Activity (PA), Sedentary Time (ST), and Physical Fitness (PF) for health. However, there is limited research on the association between PA, ST, and PF in the context of female college students, particularly in Eastern cultures. Therefore, the purpose of this study was to investigate the association between PA, ST, and PF among Eastern female college students to inform policy and practice.

METHODS

The study was conducted from February to May 2022 at East China Normal University, Shanghai, China. A total of 512 Chinese female college students participated in this study through snowball sampling. Participants' PA and ST were investigated using the International PA Questionnaire, and PF was measured using the Chinese National Student Physical Fitness Test. Independent samples t-test and binary logistic regression were used to compare the differences in PF between Active Participants (AP) and Inactive Participants (IP), as well as between Low Sedentary Participants (LSP) and High Sedentary Participants (HSP). Multinomial logistic regression was used to compare the differences in PF between Active and Low Sedentary Participants (ALSP), Active and High Sedentary Participants (AHSP), Inactive and Low Sedentary Participants (ILSP), and Inactive and High Sedentary Participants (IHSP). Data analysis was performed using Statistical Package for the Social Sciences version 28. The level of significance was set at 0.05.

RESULTS

AP showed significantly higher cardiorespiratory fitness (p < 0.05) and overall fitness (p < 0.01) than IP. Compared to IP, AP was less likely to be classified as unfit in terms of cardiorespiratory fitness [Odds Ratio (OR), 0.57; 95% Confidence Interval (CI), 0.38-0.85; p < 0.05]. Compared to IHSP, ALSP (OR, 0.44; 95% CI 0.25-0.76; p < 0.01) and AHSP (OR, 0.54; 95% CI 0.32-0.93; p < 0.05) were less likely to be classified as unfit in terms of cardiorespiratory fitness. Furthermore, compared to IHSP, AHSP (OR, 1.66; 95% CI 1.02-2.70; p < 0.05) and ILSP (OR, 2.09; 95% CI 1.16-3.77; p < 0.05) were more likely to be classified as unfit in terms of their flexibility.

CONCLUSION

There was a positive association between PA, cardiorespiratory fitness, and overall fitness. There was also an association between cardiorespiratory fitness, flexibility, and the combination of PA and ST. These findings suggest that both PA and ST can influence different PF items. Therefore, we recommend that public health policy and practice for college female students should consider PF items when selecting different PA and ST intervention strategies.

COVID-19 pandemic and adolescent mental health in China: Micro evidence and socioeconomic mechanisms

Although the impact of the COVID-19 pandemic on adolescent mental health has received sufficient attention in the medical and public health fields, analysis from the social science perspective is still lacking. By regarding the shock of COVID-19 pandemic as a quasi-natural experiment, this study adopts the Difference-in-Differences (DID) model and large microdata from Shandong Province, China, to identify the causal effect of the COVID-19 pandemic on the mental health of senior high school students. We find that the COVID-19 pandemic results in an increase of 2.5677 points in adolescent psychological problem scores, equivalent to an average decrease of 29.93% in mental health. Furthermore, results of mechanism tests show that this negative impact of the COVID-19 pandemic on adolescent mental health can be explained by a reduction in social trust, as well as widening inequalities caused by the digital divide and family income gap. Moreover, the estimates suggest that the COVID-19 pandemic has a greater negative influence on the mental health of boys and urban adolescents. Our study complements the research field on the impact of the COVID-19 pandemic on adolescent mental health and the potential socioeconomic mechanisms from a new perspective. These findings provide insights into how to safeguard adolescent mental health in China and other countries in the pandemic prevention and post-pandemic era.

Relationship between physical activity, screen-related sedentary behaviors and anxiety among adolescents in less developed areas of China

This study aimed to explore the association between physical activity, screen-related sedentary behaviors, and anxiety. The current study used latent profile analysis (LPA) to identify homogenous subtypes of anxiety among adolescents in less-developed areas of China. Data were aggregated from 6 schools in the less-developed areas of China in September 2018. In total, 900 students were evaluated using the 100-item Mental Health Test (MHT) and Youth Risk Behavior Surveillance System (YRBSS) questionnaire. The LPA was conducted to explore the potential classification of anxiety, which makes full use of all the sample data and explore heterogeneous classifications within groups. Logistic regression was used for the multifactor analysis. A P value <.05 was considered statistically significant. The entropy value suggested that the model with 3 latent profile was the best choice. There were 223 adolescents in the severe anxiety group, accounting for 24.78%. Logistics regression analysis of anxiety revealed that the risk of severe anxiety in boys was lower (odds ratio [OR] = 0.317, P < .001) than in girls. Students had a significantly lower probability of suffering from severe anxiety in using cellphones or computers ≤ 2 hours/day than those used cellphones or computers＞2 hours/day (OR = 0.391, P = .004). Decreasing screen-related sedentary behaviors should be a target of community and school-based interventions, because high screen-related sedentary behaviors were associated with higher odds of anxiety among adolescents in less developed area of China.

Perceived Difficulties in Physical Tasks and Physical Fitness in Treatment- and Non-Treatment-Seeking Youths with Obesity

Youths with obesity are more likely to experience physical and psychosocial distress which strongly limits physical activity, with consequences on the quality of life. Most evidence of lower physical fitness and physical activity levels has been reported in treatment-seeking samples, while few data are available in community samples. Our aim was to assess whether perceived difficulties in physical tasks and physical fitness performance differed between treatment- and non-treatment-seeking youths with obesity, enrolled from a hospital (H) and a school (S). Three hundred fifty-one youths (269 from H and 82 from S) were enrolled. Sports participation, sedentary habits and perceived difficulties in physical tasks were assessed by interview. Six-minute walk test (SMWD) and long jump (LJ) were performed. BMI Z-score, sedentary time and perceived difficulties were higher in H vs. S. In addition, youths from H scored worse in SMWD and LJ. For the same BMI Z-score, the perceived difficulties and physical fitness were poorer in the H compared to the S group. The setting (H) was the stronger predictor of perceived difficulties and lower performance. Our findings underline that physical aspects imposed by obesity are more evident in treatment-seeking youths. Counseling related to perceived difficulties in physical tasks and performance is useful to treat youth with obesity with appropriate and personalized modalities.

Influence of Sport Practice and Body Weight on Physical Fitness in Schoolchildren Living in the Campania Region

Background: Physical fitness (PF) levels correlate with health hallmarks at all ages. In this study, w aimed to determine the PF level of schoolchildren from the Campania Region (Italy) through health-related PF (HRPF) components, taking into account body weight and sport practice (SP). Methods: PF level was determined in 565 schoolchildren aged 10−13 (11.7 ± 1.0 yrs; m: 353, f: 212) using some of the Eurofit battery tests. Results: 77% children practiced sport, boys more than girls (86% vs. 63%, respectively; p < 0.05). Boys performed better than girls (p < 0.05) in the Plate Tapping, Standing Broad Jump, Bent-Arm Hang, and 10 × 5 m Shuttle Run tests; girls performed better in the Sit-and-Reach Test (p < 0.05). Conclusion: Overweight/obese status negatively affects the muscular strength of lower limbs, even if it progressively improves during growth. SP was revealed to be a determinant in performance only in some PF tests, likely due to the heterogeneous training level among boys and girls who practice sport.