Excessive homework, inadequate sleep, physical inactivity and screen viewing time are major contributors to high paediatric obesity

Zong X., Li H.

Wang C., Chen P., Zhuang J.

The purpose of this study was to objectively assess levels of physical activity (PA) and sedentary behavior (SB) of Chinese city children and youth aged 9 to 17 years old using accelerometers and to examine their differences by gender, age, grade, and weight status.The PA and SB of 2,163 students in 4th grade through 11th grade (M(age) = 160.87 +/- 27.00 months [13.41 +/- 2.25 years], 50.21% boys) from 11 cities in China were measured by accelerometers. The amount of time spent in SB, light PA, moderate PA, vigorous PA, and moderate-to-vigorous PA (MVPA) was computed based on cutoff points developed specifically for the Chinese children and youth. The participants were classified into normal-weight, overweight, and obese groups based on their body mass index (BMI). Paired-sample t tests were conducted to examine the differences in PA and SB between weekdays and weekend days. Multivariate analysis of variance was used to test the differences in PA and SB variables by gender, age, grade, and weight status, respectively.Chinese city children and youth spent an average of 28.26 +/- 17.66 min/day in MVPA and 521.50 +/- 110.02 min/day in SB. Only 9.4% of boys and 1.9% of girls met the recommendation of 60 min/day of MVPA. Chinese city children and youth were more active during weekdays than during weekend days, and boys were more active than girls; older children and youth spent more daily time in MVPA, but also spent more time being sedentary. No differences in PA and SB were found across different BMI categories.The findings warn of the insufficiency of PA and the excess of SB in Chinese city children and youth.

Gubbels J.S., van Assema P., Kremers S.P.

Energy balance-related behavioral patterns find their origin in early childhood. The current paper provides an overview of studies that have examined such behavioral patterns, i.e., the clustering of dietary behaviors, physical activity, and/or sedentary behavior. The paper discusses the importance of examining energy balance-related behavioral patterns in children, outlines methods to examine these patterns, and provides examples of patterns that have been found (e.g., the universal sedentary-snacking and healthy intake patterns, as well as more unique or local patterns), child and parental characteristics predicting such patterns (e.g., child gender and maternal educational level), and the relationship of these patterns with overweight and related measures.

Song Y., Wang H., Ma J., Wang Z.

Based on the data from six Chinese National Surveys on Students Constitution and Health (CNSSCH) from 1985 to 2010, we explored the secular trend in the prevalence of obesity in urban Chinese children over a period of 25 years. The aim of this study was to examine the gender disparities in the prevalence of childhood obesity over time. The standardized prevalence of obesity in Chinese children increased rapidly during the past 25 years from 0.2% in 1985 to 8.1% in 2010. The increasing trend was significant in all age subgroups (p

Yu Z., Han S., Chu J., Xu Z., Zhu C., Guo X.

Background Overweight/obesity is a serious public health problem that affects a large part of the world population across all age and racial/ethnic groups. However, there has not been a meta-analysis of the prevalence of childhood and adolescent overweight/obesity in China during the past 30 years. Methods The China National Knowledge Infrastructure and Wanfang DATA, MEDLINE, EMBASE and Cumulative Index to Nursing and Allied Health Literature were searched for relevant studies published between January 1970 and June 2012. The prevalence of overweight/obesity over time was pooled using Stata/SE, version 9. Summary statistics (odds ratios, ORs) were used to compare sex-specific and urban-rural preponderance of overweight/obesity using Review Manager. Results After screening 1326 papers, we included 35 papers (41 studies), most of medium quality. The prevalence of overweight/obesity increased from 1.8% (95% confidence interval [CI], 0.4%–3.1%) and 0.4% (95% CI, −0.1% to −0.8%) respectively in 1981–1985 to 13.1% (95% CI, 11.2%–15.0%) and 7.5% (95% CI, 6.6%–8.4%) respectively in 2006–2010. The average annual increase was 8.3% and 12.4% respectively. Boys were more likely to be overweight/obese than girls (OR, 1.36; 95% CI, 1.24–1.49 and OR, 1.68; 95% CI, 1.52–1.86 respectively). The prevalence of overweight/obesity was higher in urban areas than in rural areas (OR, 1.66; 95% CI, 1.54–1.79 and OR, 1.97; 95% CI, 1.68–2.30 respectively). For age-specific subgroup analyses, both overweight and obesity increased more rapidly in the toddler stage than in other developmental stages. Sensitivity analyses showed that sample-size differences, study quality, overweight/obesity criteria and geographical distribution affected overweight/obesity prevalence. Conclusions Toddlers and urban boys were at particularly high risk; the prevalence in these groups increased more rapidly than in their counterparts. Public health prevention strategies are urgently needed to modify health behaviors of children and adolescents and control overweight/obesity in China.

Yang Z., Huffman S.L.

Concerns about the increasing rates of obesity in developing countries have led many policy makers to question the impacts of maternal and early child nutrition on risk of later obesity. The purposes of the review are to summarise the studies on the associations between nutrition during pregnancy and infant feeding practices with later obesity from childhood through adulthood and to identify potential ways for preventing obesity in developing countries. As few studies were identified in developing countries, key studies in developed countries were included in the review. Poor prenatal dietary intakes of energy, protein and micronutrients were shown to be associated with increased risk of adult obesity in offspring. Female offspring seem to be more vulnerable than male offspring when their mothers receive insufficient energy during pregnancy. By influencing birthweight, optimal prenatal nutrition might reduce the risk of obesity in adults. While normal birthweights (2500-3999 g) were associated with higher body mass index (BMI) as adults, they generally were associated with higher fat-free mass and lower fat mass compared with low birthweights (

Maher C., Olds T.S., Eisenmann J.C., Dollman J.

Background: Both reduced moderate-to-vigorous physical activity (MVPA) and increased screen time have been implicated in the aetiology of childhood overweight/obesity. This study aimed to determine which behaviour had the stronger association with overweight/obesity. Method: 2200 randomly selected 9- to 16-year-old Australians provided four 24-h use-of-time recalls. Participants were classified into weight status categories and as high or low physical active, and high or low screen time according to Australian guidelines (≥60 min MVPA; ≤120 min recreational screen time daily). Multivariate logistic regression was used to calculate the odds ratios (OR) for overweight/obesity for each screen time and MVPA category. Results: Increased likelihood of overweight or obese was often associated with high screen time (ORs, 2.13–2.55 for boys and 1.47–1.72 for girls), but only sometimes and less strongly associated with low MVPA (ORs, 0.49–2.55 for boys and 1.06–1.47 for girls). Analyses conducted for combined screen time and MVPA categories showed screen time to be a stronger indicator of weight status than physical activity, especially in boys. Conclusion: Overweight and obesity were more strongly associated with screen time than physical activity. Screen time may be an important target for interventions aimed at reducing childhood overweight and obesity.

Prentice-Dunn H., Prentice-Dunn S.

This systematic review examined the associations of physical activity (PA) and sedentary behavior to childhood overweight and obesity in cross-sectional studies from the last 10 years. Cross-sectional approaches are cost-effective methods for identifying relationships that can then be followed by longitudinal studies to establish temporality and create targeted interventions. The 17 selected studies contained a variety of measures of PA and sedentary behavior. PA was related negatively to child weight status in some studies; however, it was not associated in others. In general, sedentary behaviors were positively associated with weight status. However, gender differences appeared in some studies for each variable. Limitations of cross-sectional approaches were discussed, as was the need for more accurate measures of PA, sedentary behavior, and body composition.

Misra A., Shah P., Goel K., Gupta N.

Rapidly changing dietary practices and a sedentary lifestyle have led to increasing prevalence of childhood obesity (5–19 yr) in developing countries recently: 41.8% in Mexico, 22.1% in Brazil, 22.0% in India, and 19.3% in Argentina. Moreover, secular trends indicate increasing prevalence rates in these countries: 4.1 to 13.9% in Brazil during 1974–1997, 12.2 to 15.6% in Thailand during 1991–1993, and 9.8 to 11.7% in India during 2006–2009. Important determinants of childhood obesity include high socioeconomic status, residence in metropolitan cities, female gender, unawareness and false beliefs about nutrition, marketing by transnational food companies, increasing academic stress, and poor facilities for physical activity. Childhood obesity has been associated with type 2 diabetes mellitus, the early-onset metabolic syndrome, subclinical inflammation, dyslipidemia, coronary artery diseases, and adulthood obesity. Therapeutic lifestyle changes and maintenance of regular physical activity through parental initiative and social support interventions are the most important strategies in managing childhood obesity. Also, high-risk screening and effective health educational programs are urgently needed in developing countries.

Tam C.S., Ravussin E.

Childhood obesity is a significant public health problem, affecting one in five children in the United States. At the crux of this issue is a dysregulation of energy intake and energy expenditure. This review will provide an overview on energy and nutrient balance. We discuss energy balance studies in children using indirect and direct measures, and focus particularly on obesity as a deleterious consequence in childhood survivors of cancer. Obesity affects 11-57% of children with acute lymphoblastic leukemia, probably due to increased energy intake and reduced energy expenditure secondary to reduced habitual activity caused by fatigue. However, most of the studies in children with leukemia are retrospective, use BMI as a measure of obesity, and are inconclusive about the impact of the type of treatment on the development of obesity later in life. To better understand the etiology of obesity in both healthy and sick children, we need to undertake nutrient balance studies with appropriate measures of fat mass and fat distribution while keeping in mind the influence of normal tissue growth and puberty on energy balance.

Cui Z., Hardy L.L., Dibley M.J., Bauman A.

Sedentary behaviours (television, video and computer) are related to health outcomes independent of physical activity. Few studies have examined trends and correlates of sedentary behaviours among youth in developing nations. The current study is to examine temporal trends in sedentary behaviours and recent correlates of screen use in Chinese children during a period of economic transition. Secondary analysis of China Health and Nutrition Surveys. Cross-sectional data on sedentary behaviours including screen use among children aged 6-18 years from four surveys in 1997 (n = 2,469), 2000 (n = 1,838), 2004 (n = 1,382) and 2006 (n = 1,128). Temporal trends in screen use by socio-demographic characteristics were examined. The correlates of spending more than 2 hours per day on screen time in the most recent survey data (2006, n = 986) were analysed using survey logistic regression analysis. Daily screen time significantly increased in each subgroup by age, sex and urban/rural residence, with the largest increase for urban boys aged 13-18 years from 0.5 hours to 1.7 hours, and for rural boys aged 6-12 years from 0.7 hours to 1.7 hours (p < 0.0001). Daily time in both homework and extracurricular cultural activity increased significantly from 2000 to 2004 but was stable from 2004 to 2006. Boys (OR: 1.41, 95%CI: 1.09 -1.82), having a TV in the bedroom (OR: 1.86, 95%CI: 1.15 - 3.01), having access to internet at home (OR: 1.93, 95%CI: 1.12 - 3.31) or at internet cafés (OR: 2.01, 95%CI: 1.21 - 3.34), or often watching TV with parents (OR: 2.27, 95%CI: 1.37 - 3.74) were all associated with being more likely to be high screen users (≥ 2 hours/day). While children aged 13-18 years (OR: 0.67, 95%CI: 0.46-0.97) were less likely to be high screen users. Children whose parents often have rules on their TV viewing (OR: 0.64, 95%CI: 0.37 - 1.10) were slightly but not significantly less likely to be high screen users. This study confirms sedentary behaviour has increased over the last decade in Chinese children. Efforts to ensure Chinese youth meet screen time guidelines include limiting access to screen technologies and encouraging parents to monitor their own screen time and to set limits on their child's screen time.

Shan X., Xi B., Cheng H., Hou D., Wang Y., Mi J.

de Onis M., Blössner M., Borghi E.

Childhood obesity is associated with serious health problems and the risk of premature illness and death later in life. Monitoring related trends is important.The objective was to quantify the worldwide prevalence and trends of overweight and obesity among preschool children on the basis of the new World Health Organization standards.A total of 450 nationally representative cross-sectional surveys from 144 countries were analyzed. Overweight and obesity were defined as the proportion of preschool children with values >2 SDs and >3 SDs, respectively, from the World Health Organization growth standard median. Being "at risk of overweight" was defined as the proportion with values >1 SD and ≤2 SDs, respectively. Linear mixed-effects modeling was used to estimate the rates and numbers of affected children.In 2010, 43 million children (35 million in developing countries) were estimated to be overweight and obese; 92 million were at risk of overweight. The worldwide prevalence of childhood overweight and obesity increased from 4.2% (95% CI: 3.2%, 5.2%) in 1990 to 6.7% (95% CI: 5.6%, 7.7%) in 2010. This trend is expected to reach 9.1% (95% CI: 7.3%, 10.9%), or ≈60 million, in 2020. The estimated prevalence of childhood overweight and obesity in Africa in 2010 was 8.5% (95% CI: 7.4%, 9.5%) and is expected to reach 12.7% (95% CI: 10.6%, 14.8%) in 2020. The prevalence is lower in Asia than in Africa (4.9% in 2010), but the number of affected children (18 million) is higher in Asia.Childhood overweight and obesity have increased dramatically since 1990. These findings confirm the need for effective interventions starting as early as infancy to reverse anticipated trends.

Collison K.S., Zaidi M.Z., Subhani S.N., Al-Rubeaan K., Shoukri M., Al-Mohanna F.A.

The prevalence of obesity and overweight is increasing globally. Frequently coexisting with under-nutrition in developing countries, obesity is a major contributor to chronic disease, and will become a serious healthcare burden especially in countries with a larger percentage of youthful population. 35% of the population of Saudi Arabia are under the age of 16, and adult dietary preferences are often established during early childhood years. Our objective was to examine the dietary habits in relation to body-mass-index (BMI) and waist circumference (W_C), together with exercise and sleep patterns in a cohort of male and female Saudi school children, in order to ascertain whether dietary patterns are associated with obesity phenotypes in this population. 5033 boys and 4400 girls aged 10 to 19 years old participated in a designed Food Frequency Questionnaire. BMI and W_C measurements were obtained and correlated with dietary intake. The overall prevalence of overweight and obesity was 12.2% and 27.0% respectively, with boys having higher obesity rates than girls (P ≤ 0.001). W_C and BMI was positively correlated with sugar-sweetened carbonated beverage (SSCB) intake in boys only. The association between male BMI and SSCB consumption was significant in a multivariate regression model (P < 0.0001). SSCB intake was positively associated with poor dietary choices in both males and females. Fast food meal intake, savory snacks, iced desserts and total sugar consumption correlated with SSCB intake in both boys (r = 0.39, 0.13, 0.10 and 0.52 respectively, P < 0.001) and girls (r = 0.45, 0.23, 0.16 and 0.55 respectively, P < 0.001). Older children reported eating significantly less fruit and vegetables than younger children; and less eggs, fish and cereals. Conversely, consumption of SSCB and sugar-sweetened hot beverages were higher in older versus younger children (P < 0.001). BMI and W_C were negatively correlated with hours of night-time sleep and exercise in boys, but only with night time sleep in girls, who also showed the lowest frequency of exercise. A higher intake of SSCB is associated with poor dietary choices. Male SSCB intake correlates with a higher W_C and BMI. Limiting exposure to SSCB could therefore have a large public health impact.

Gao Y., Griffiths S., Chan E.Y.

Overweight and obesity pose a challenge to public health in China. According to Chinese definition, 303 million Chinese are overweight (body mass index, BMI >or= 24 kg m(-2)). Among them, 73 million are clinically obese (BMI >or= 28 kg m(-2)). In line with the global trend, the rate of obesity in China continues to increase, with associated morbidity and mortality. This study was to identify interventions, which are effective in Mainland Chinese society.All non-drug-controlled interventions (>or=3 months) in Mainland China, which used anthropometric outcome measures, were selected from three Chinese and nine international electronic databases (before May 2006) and included in this systematic review.A total of 20 studies met the selection criteria and were included in the review. Among them only one was published in an international journal. Most studies combined at least physical activity, dietary intervention and health education. Seventeen studies (85%) reported significant effects in anthropometric measurement outcomes.Comprehensive interventions with at least physical activity, dietary intervention and health education may be effective in reducing obesity in Chinese children. The role of grandparents as carers in the one-child society is worth considering further. Current evidence of effective interventions for adults is limited. Publication bias in Chinese databases should be taken into account.

Tang L., Zhang M., Li W., Mo L., Tan D., Peng W.

Rodríguez-Gutiérrez E., Torres-Costoso A., Jiménez-López E., Mesas A.E., Díaz-Goñi V., Guzmán-Pavón M.J., Beneit N., Martínez-Vizcaíno V.

Objective: To examine the associations between gradients of average daily temperature and sunlight hours with daily steps over a 35-week period in school-aged children and to evaluate whether there were differences by sex. Methods: We conducted a follow-up study involving 655 children (50.8% girls, mean age 10.45 ± 0.95 years) from six public primary schools in Cuenca, Spain. We measured daily steps using Xiaomi Mi Band 3 Smart Bracelets (Xiaomi Corporation, Beijing, China) from October 2022 to June 2023 (over 35 weeks). We collected the average daily temperature from the local weather station in Cuenca and the sunlight hours during the same period. We used ANCOVA models and LOESS regression to examine the associations between gradients of average daily temperature and daily hours of sunlight with daily steps. Additionally, we performed a multiple linear regression model. Results: Our findings revealed significant variations in daily steps across the 35 weeks. The relationship between environmental factors and daily steps was non-linear in both girls and boys. The optimal values for higher activity levels were an average temperature of 14 °C and 13 h of sunlight. Furthermore, a 1 °C increase in temperature was associated with an increase of 74 ± 130 steps/day, while an increase of one hour of sunlight was associated with an increase of 315 ± 237 steps/day. However, the sunlight hours may act as a moderating factor. Conclusions: Our study showed a non-linear association between average daily temperature and the sunlight hours with daily steps over a 35-week period. Appropriate strategies may be needed to promote physical activity during periods of extreme temperatures or sunlight exposure.

Fan Y., Wang D., Wang W., Chen H., Lin J., Lin W., Yin L., Zhang R., Ma Z., Fan F.

To examine the cross-sectional and longitudinal bidirectional associations of depression and anxiety symptoms with the development of obesity over time among children and adolescents in different age groups from childhood to young adulthood.

Demir P., Baskaran K., Ramos P.L., Naduvilath T., Sankaridurg P., Macedo A.F.

AbstractPurposeThe prevalence of myopia in Scandinavia tends to be lower than in other parts of the world. This study aimed to investigate the incidence of myopia and its predictors in Swedish children to characterise this trend.MethodsA 2‐year longitudinal study was conducted following a cohort of schoolchildren aged 8–16 years. Myopia was defined as a spherical equivalent refraction (SER) ≤ −0.50 D. The study enrolled 128 participants, 70 (55%) females with a mean age of 12.0 years (SD = 2.4).ResultsThe cumulative incidence of myopia during the follow‐up period was 5.5%, and the incidence rate of myopia was 3.2 cases per 100 person‐years. Participants with myopia at baseline exhibited a faster increase in refractive error during the follow‐up period. Likewise, participants with two myopic parents exhibited a more marked change towards myopia, regardless of their initial refractive error.ConclusionIn the current study, similar to prevalence, the incidence of myopia was low when compared with other parts of the world. These results lead us to formulate a new hypothesis that the normal emmetropisation process may be protected by low educational pressure practised in Sweden during early childhood. Further research is necessary to test this new hypothesis.

Xue X., Makela C.

Critical Policy Analysis (CPA) is a framework for examining policies that focuses on power, privilege, and social inequalities. Research on the impact of the Double Reduction educational policy is varied as the policy is new and may not be universally equitable for all students. Some studies have demonstrated the anticipated positive outcomes of the policy, however, contrasting findings have been reported in other studies. This analytical paper aims to provide a comprehensive understanding of the Double Reduction educational policy in China and discuss the implications for equity and inclusion through the lens of CPA. It addresses gaps in current research by evaluating the policy’s effectiveness and its differential impact on various student demographics. By examining existing literature, this paper offers recommendations for policymakers to enhance the impact of the Double Reduction educational policy, particularly for students from disadvantaged socioeconomic, ethnic minority, and geographic backgrounds.

Alexandrova I.E.

Introduction: Being a mandatory component of the educational process, homework remains its least regulated component. At the same time, recent scientific research findings give evidence of study overload and daily routine disruption in schoolchildren due to, inter alia, a significant amount of homework. The purpose of this work is to assess the functional state of the organism of schoolchildren in the process of doing homework for further optimization of this type of educational activity. Materials and methods: The study was based on testing of mental performance of schoolchildren in grades 1–8, which is an integral indicator of the functional state of the body and is crucial for educational activities. The technique of proofreading tests was used to assess the main parameters of mental performance: the number of characters viewed, the number of mistakes made, and their ratio. The tests were conducted before and after the children completed their homework. Results and discussion: A decline in mental performance was observed in the majority of the examined: the number of viewed characters decreased while the number of errors significantly increased after doing homework. First and second-year primary school children made 9.62 errors against 13.07; fifth graders – 3.49 against 7.85 errors (p < 0.001); and eighth graders – 5.86 against 7.39 (p < 0.05). A significant proportion of schoolchildren (28.6 to 72.7 %) had adverse shifts in mental performance characteristic of severe fatigue. The results show accumulated fatigue by the start of independent work with already deteriorated performance related to previous intensive studies at school; after insufficient rest against the background of a decline in physiological functions of the body, which is consistent with previous findings. Conclusion: It is essential to optimize organization of homework based on updated principles of mental health given its current features.

Hao L., Fan Y., Zhang X., Rong X., Sun Y., Liu K.

BackgroundDevelopment of physical and cognitive function is very critical in 4~5 years children. It has been addressed in this research if the 18 weeks of specific functional training with or without cognitive training can be effective on improving fitness and cognitive development in 4~5 years preschool children.MethodsA total of 126 preschool children in the 4~5 age range were selected as participants and randomly assigned to one of four groups: the control group (C), the functional physical training group (P), the cognitive training group (CT), and the functional physical training combined with cognitive training group (PCT).ResultsThe results revealed significant pre/post differences in body height and weight among all four groups of children. Furthermore, there was no significant difference in physical fitness between the C group and the CT group after the intervention. However, the children in the P group and the PCT group showed significant improvements in three indicators including standing long jump, continuous jump, and 10-meter shuttle running. Additionally, the children in P group, CT group, and the PCT group demonstrated significant improvement in simple reaction time, attention, and spatial memory. No significant cognitive improvement was found in C group.ConclusionFunctional physical training with or without cognitive intervention can promote both physical fitness and cognitive development in children aged 4~5 years. Cognitive training alone can significantly improve cognitive function but not physical. Therefore, functional physical training can be used alone to improve the physical and cognitive abilities for aged 4~5 years old children.

Hao L., Fan Y., Zhang X., Rong X., Sun Y., Liu K.

Abstract Development of physical and cognitive function is very critical in 4–5 years children. It has been addressed in this research if the specific functional training with or without cognitive training can be effective on improving fitness and cognitive development in 4–5 years preschool children. A total of 126 preschool children in the 4–5 age range were selected as participants and randomly assigned to one of four groups: the control group (C), the physical function training group (P), the cognitive training group (CT), and the physical function training combined with cognitive training group (PCT). The results revealed significant pre/post differences in body height and weight among all four groups of children. Furthermore, there was no significant difference in physical fitness between the C group and the CT group after the intervention. However, the children in the P group and the PCT group showed significant improvements in three indicators including standing long jump, continuous jump, and 10-meter shuttle running. Additionally, the children in P group, CT group, and the PCT group demonstrated significant improvement in simple reaction time, attention, and spatial memory. No significant cognitive improvement was found in C group. Functional physical training with or without cognitive intervention can promote both physical fitness and cognitive development in children aged 4–5 years. Cognitive training alone can significantly improve cognitive function but not physical. Therefore, functional physical training can be used alone to improve the physical and cognitive abilities for aged 4–5 years old children.

Hong Y., Ullah R., Wang J., Fu J.

Abstract Background Recent decades have shown a rapid increase in the prevalence of overweight and obesity among Chinese children based on several national surveys. Restrictions due to the coronavirus disease 2019 outbreak have worsened its epidemiology. This review updates the trends in the prevalence of overweight and obesity among Chinese children and adolescents and analyzes the underlying reasons to provide evidence for better policy making. Methods Studies published in English and Chinese were retrieved from PubMed, Google Scholar, China National Knowledge Infrastructure and Wanfang. Results The prevalence of overweight and obesity has been increasing for decades and varies with age, sex and geography but is more pronounced in primary school students. The increase in obesity in boys appeared to be slower, whereas that in girls showed a declining trend. The northern areas of China have persistently maintained the highest levels of obesity with a stable trend in recent years. Meanwhile, the prevalence in eastern regions has dramatically increased. Notably, the overall prevalence of obesity in children has shown a stabilizing trend in recent years. However, the occurrence of obesity-related metabolic diseases increased. The effect of migrants floating into east-coast cities should not be neglected. Conclusions The high prevalence of overweight and obesity among Chinese children and adolescents persists but with varying patterns. Obesity-related metabolic diseases occur more frequently despite a stable trend of obesity. Multiple factors are responsible for the changing prevalence. Thus, comprehensive and flexible policies are needed to effectively manage and prevent the burden of obesity and its related complications.

Chu M., Fang Z., Lee C., Hu Y., Li X., Chen S., Chen T., Chen X., Chiang Y.

Children’s psychological well-being is critical for students’ school performance and mental health. This study developed the Chinese Children’s Subjective Well-being Scale and explored an appropriate strategy to improve children’s subjective well-being from the collaboration between school and home perspective. Based on a literature review, focus group interviews, expert validity, factor structure and confirmatory factor analysis, this study developed the Chinese Children’s Subjective Well-being Scale. We then enrolled 289 grade 3–6 students from a public primary school in southeastern China to conduct multiple linear regression analysis. The Chinese Children’s Subjective Well-being Scale had good reliability and validity. Homework anxiety was negatively associated with subjective well-being (β = -0.21. p = 0.011). Family interaction and support improved subjective well-being. Less parental supervision and family conflict could buffer the negative effect of homework anxiety on subjective well-being. The Chinese Children’s Subjective Well-being Scale can be used with primary school students in China. This study also recommended that governments and education practitioners focus on optimizing collaboration between school and home to improve children’s subjective well-being by reducing their homework anxiety and increasing the harmonious family atmosphere (more family interaction and support and less parental supervision and family conflict).

Redondo-Flórez L., Ramos-Campo D.J., Clemente-Suárez V.J.

Several studies involving students have been developed with the objective to analyse the influence of different factors on academic performance. Nevertheless, all these studies were focused on stress and sympathetic modulation response instead of contemplating other physiological parameters that may affect academic performance. The aim of the present study was to analyse body composition, cardiovascular, sleep habits and physical activity factors related to the academic performance of university students. Two hundred and sixty-one students with bachelor’s degrees in physical activity and sports science participated in the present study (age: 22.49 ± 3.84 years; weight: 73.94 ± 11.4 kg; height: 176.28 ± 7.68 cm; 87.7% males). Participants were divided into two groups according to their academic performance: low academic performance group (LAPG) and high academic performance group (HAPG). Body composition, blood pressure, physical activity and sleep habits were measured, and maximum oxygen uptake was estimated by the Cooper’s 12 min run test. The results show that students with a high academic performance presented a higher VO2 max than the LAPG (LAPG = 40.32 ± 6.07; HAPG = 47.91 ± 6.89 mL/kg/min; p < 0.001), as well as lower diastolic blood pressure (LAPG = 72.44 ± 14.27; HAPG = 67.48 ± 13.50 mmHg; p < 0.01) and insomnia levels caused by breathing problems (LAPG = 0.37 ± 0.8; HAPG = 0.13 ± 0.42 a.u.; p = 0.046). Therefore, we found a relevant association between academic performance and VO2 max, diastolic blood pressure, and insomnia caused by breathing problems. These results highlight the importance of applying different programmes that may improve these factors, especially those related to physical activity and sleep habits in order to improve academic achievement.

Demir P., Baskaran K., Ramos P.L., Naduvilath T., Sankaridurg P., Macedo A.F.

AbstractBackgroundThe prevalence of myopia in Scandinavia seems to differ from other parts of the world and the reasons remain poorly investigated. The current study investigated the incidence of myopia, myopic shift, and associated risk factors in Swedish schoolchildren. This study also investigated the development of refractive error under the effect of COVID-19 restrictions.MethodsThis longitudinal study was conducted between Jan-2019 and June-2021 in which a cohort of Swedish schoolchildren aged 8-16 years were recruited. Myopia was defined as spherical equivalent refraction (SER) -0.50D. Myopic shift was defined as a minimum change in SER of -0.50D between each visit. Cumulative incidence (CIN) and incidence rate (IRA) were computed. Cox-regression and linear mixed models were used to modulate myopic shift and changes in SER.ResultsThe study enrolled 128 participants, 86% Caucasian, 70 females, mean age 12.0 years (SD=2.4). The CIN of myopia during the two-years follow-up was 5.5%, IRA of myopia was 3.2 cases per 100 person-years. The CIN of myopic shift during the two-years was 21.0%, IRA of myopic shift was 12.4 cases per 100 person-years. Cox regression revealed that the probability of myopic shift reduced withageand increased withaxial length/corneal-curvature ratio. Myopic children at the baseline and children with two myopic parents showed a significant faster-paced negative SER change over time. Changes in SER during the first year of the study were more marked than changes during the second year that coincided with the Covid pandemic.ConclusionsIn the current study the incidence of myopia and myopic shift was low when compared with countries in East Asia. Parental myopia remains a critical factor to consider when predicting myopia progression. Progression of myopia was unaffected by restrictions imposed during COVID-19 in Sweden. In addition to ethnicity, lifestyle and adequate educational pressure might be factors keeping prevalence of myopia under control in Scandinavia. Further studies to investigate these hypotheses are warranted.Key messagesWhat is already known on this topicThe rate of myopia is increasing in many regions of the world, and the recent lockdowns caused by the COVID-19 pandemic has exacerbated this problem. The highest rates of myopia are from East Asia and are in sharp contrast to the low levels reported from Scandinavia. There is a lack of studies exploring the incidence of myopia in the Scandinavian population. We conducted this study to identify the incidence of myopia among Swedish children and to determine whether the COVID-19 pandemic had any significant effects.What this study addsThis study is the first to report the incidence of myopia and the myopic shift in Scandinavia. The study results showed that myopia and myopic shift were low compared to other parts of the globe. Myopia progression was not affected by the pandemic, perhaps due to Sweden’s avoidance of severe restrictions during the outbreak. Parental myopia was the significant risk factor for the progression of myopia in this cohort of Swedish school children.How this study might affect research, practice, or policyIt is clear from this study’s results that parental myopia is a risk factor for myopia and is an influential predictor to consider in clinical trials that evaluate interventions to slow down the progression of myopia. Outdoor lifestyle and less educational pressure at young ages may be contributing factors to the low prevalence and incidence of myopia in Swedish children.SynopsisIncidence of myopia was low in Swedish schoolchildren despite COVID-19 pandemic and the associated risk factor was parental myopia and younger age.

Alexandrova I.E.

Introduction: A high level of competition for the quality and quantity of acquired knowledge is observed in modern society. It entails an increase in time children spent studying in school and doing their homework, the latter being an integral and critical component of the educational process. Objective: To summarize and systematize the results of research on physiological, hygienic and pedagogical challenges of doing homework as well as on rationalization and optimization of this type of schoolchildren’s activity in the digital educational environment aimed at preventing fatigue and school-related diseases, including in the historical perspective. Materials and methods: Appropriate publications in Russian and English languages were search for in the Russian Science Citation Index, PubMed, and Scopus databases, print editions of scientific journals, and other sources. Forty-two full-text papers published in 1989–2021 were eligible for inclusion in the review. Results and discussion: The data analysis shows that contemporary schoolchildren spend significantly more time doing homework than is recommended, which disrupts their daily routine by reducing the duration of walks and night sleep and deteriorates health. Distance learning during the COVID-19 pandemic only exacerbated the situation. A whole number of publications in pedagogy are devoted to didactic issues of homework while little attention is paid to health-related improvement of conditions and organization of this important type of educational activity. Conclusion: Global digitalization and the associated transformation of the education system necessitates hygienic optimization of all the components of the learning process, including homework, the content of which has undergone significant changes.

Lu Y., Yu K., Gan X.

This study aimed to analyze the impacts of a 12-week core strength training (CST) and goal-setting (GS) program on the core endurance, agility, sprinting, jumping, grip strength, and exercise attitude in a group of adolescents. This study followed a randomized parallel design in which 362 adolescents (age: 14.5 ± 1.07 years; body mass index: 19.82 ± 3.64) were allocated to a GS (n = 89), CST (n = 92), or GS + CST (n = 90) program or to a control group (n = 91). Participants were assessed two times (baseline and postintervention) for the following tests: (i) 50 m dash, (ii) grip strength, (iii) long jump, (iv) 1000 m running for boys and 800 m for girls, (v) core endurance, and (vi) exercise attitude. Significant differences (p < 0.05, η2p = 0.035−0.218) were found between the four groups of the six components of physical fitness and the three components of attitude toward exercise (target attitudes, behavioral habits, and sense of behavioral control). Between-group analysis revealed that the GS + CST had significant advantages (p < 0.05) over the CON in terms of the 50 m dash (Cohen’s d = 0.06), grip strength (Cohen’s d = 0.19_left, 0.31_right), 800/1000 m running (Cohen’s d = 0.41), core endurance (Cohen’s d = 0.95), and sense of behavioral control (Cohen’s d = 0.35). Between-group analysis also revealed that the CST had significant advantages over the CON in terms of grip strength (Cohen’s d = 0.27_left, 0.39_right), 50 m (Cohen’s d = 0.04), long jump (Cohen’s d = 0.21), 800/1000 m (Cohen’s d = 0.09), and core stability (Cohen’s d = 0.63), which were significantly different from CON (p < 0.05). GS differed from CON only on 50 m (Cohen’s d = 0.02) and core stability (Cohen’s d = 0.13) with a small effect (p < 0.05). We conclude that the combined intervention of GS and CST is more effective in promoting fitness in adolescents, i.e., GS + CST > CST and GS + CST > GS.

Kuzik N., da Costa B.G., Hwang Y., Verswijveren S.J., Rollo S., Tremblay M.S., Bélanger S., Carson V., Davis M., Hornby S., Huang W.Y., Law B., Salmon J., Tomasone J.R., Wachira L., et. al.

The purpose of this systematic review was to examine the associations between school-related sedentary behaviours and indicators of health and well-being in children and youth (~ 5–18 years) attending school. This review was conducted to inform the development of School-Related Sedentary Behaviour Recommendations. Peer-reviewed, published, or in-press articles in English were included. Reviews, meta-analyses, and case studies were excluded; all other study designs were eligible. Further, articles had to meet the a priori study criteria for population, intervention, comparator (PROSPERO ID: CRD42021227600). Embase, MEDLINE® ALL, and PsycINFO were searched. Risk of bias was assessed for individual experimental studies using the Cochrane risk of bias assessment tool, and in observational studies based on the GRADE framework and in line with previous systematic reviews examining sedentary behaviours in children. Overall quality of evidence was assessed using the GRADE framework for each outcome category and study design. Results were synthesized narratively, grouped by study design and outcome category. Further, several high-level summaries were conducted to help interpret results. Evidence was synthesized from 116 reports, including 1,385,038 participants and 1173 extracted associations. More school-related sedentary behaviour was favourably associated with nearly one-third of extracted associations for cognitive (33%) and social-emotional (32%) indicators (e.g., less anxiety), but unfavourably associated with other movement behaviours (e.g., less physical activity) (35%). Active lessons were favourable (72%), compared to more school-related sedentary behaviours, when examining associations for all health and well-being indicators. More homework was favourable across all health and well-being indicators in 4% of extracted associations for primary school children, and 25% of extracted associations for secondary school children. However, ≥2 h/day of homework appeared to be unfavourable for health and well-being. Limitations for synthesized studies included generally low quality of evidence and a lack of studies in South American, African, or low-middle income countries. Findings can help inform policy makers, schools, and teachers, regarding the amount of homework assigned and the introduction of active lessons into the classroom to enhance health and well-being of children. More research is needed examining school-related sedentary behaviours and indicators of health and well-being in low- and middle-income countries.