Overweight, obesity, and screen-time viewing among Chinese school-aged children: National prevalence estimates from the 2016 Physical Activity and Fitness in China—The Youth Study

Purpose: This study presents the most recent estimates of prevalence of overweight, obesity, and screen-time viewing among Chinese school-aged children. Demographic differences in these estimates between sexes and resident locales were also examined.Methods: Cross-sectional analyses of 116,615 Chinese school children 9 to 17 years of age who participated in the 2016 Physical Activity and Fitness in China—The Youth Study project. Outcomes were the prevalence of children's overweight(85 th ≤ body mass index(BMI) < 95 th percentile) and obesity(BMI ≥95 th percentile)(defined by the Working Group on Obesity in China) and not meeting screen-time viewing recommendations("not meeting" was defined as more than 2 h per day of viewing activities after school). Analyses were conducted on the whole sample and by school grade cohorts(primary, junior middle, and junior high schools), sex, and residence locales(urban, rural).Results: Overall, 14.4%(95% confidence interval(CI): 13.8%–15.0%) of children and adolescents were overweight, 11.9%(95%CI: 11.0%–13.0%) were obese, and 36.8%(95%CI: 34.7%–38.9%) did not meet screen-time viewing recommendations. Across the 3-grade cohorts, boys were more likely to be obese than girls, and primary and junior middle school children living in urban areas were more likely to be obese than those living in rural areas. Primary and junior middle school boys were less likely to meet screen-time recommendations than girls, and junior high school children living in urban areas were less likely to meet screen-time recommendations than school children of the same grades living in rural areas.Conclusion: In 2016, the prevalence of obesity among Chinese school children was about 12%, and about 37% of them did not meet screen-time viewing recommendations. The prevalence of obesity and sedentary behavior was generally higher among boys than among girls, and it was higher for children living in urban areas than for those living in rural areas.

Prevalence, Factors Associated with Obesity and Overweight among Students in Brazzaville in 2020

Background: The prevalence of obesity is increasing dramatically around the world and it is reasonable to assume that young people attending school in Brazzaville are not spared. The objective of this study was to determine the prevalence, as well as the factors associated with obesity and overweight among students in Brazzaville. Methods: This is a cross-sectional study, conducted as a questionnaire survey with 2052 pupils (869 boys and 1183 girls, aged 14 to 18). Obesity and overweight were determined from the body mass index and reference curves of the International Obesity Task Force (IOTF), the associated factors, by performing the logistic regression. Results: The prevalence of overweight in private and public institutions was 15.6% versus 5.5% (p < 0.001) and obesity prevalence was 4.0% versus 1.5% (p < 0.001), respectively. The main factors associated with obesity and overweight were: parents’ monthly income (OR = 1.73), car as a means of transportation (OR = 2.75) and family history of obesity (OR = 7.73). On the other hand, attending a public school, walking and high levels of physical activity had a protective effect against obesity in this population. Conclusion: The prevalence of obesity was higher in private institutions and required management and prevention strategies.

Modeling the dose-response rate/associations between VO2max and self-reported Physical Activity Questionnaire in children and adolescents

Background'. This study sought to explore the dose—response rate/association between aerobic fitness (VC)2max) and self-reported physical activity(PA) and to assess whether this association varies by sex, age, and weight status.Methods. VO2max was assessed using the 20・m shuttle・run test. PA was assessed using the Physical Activity Questionnaire (PAQ) for Adolescents(aged > 11 years, PAQ-A) or for Children (aged <11 years, PAQ-C). The associations between V02raax and PAQ were analyzed using analysisof covariance (ANCOVA), adopting PAQ and PAQ2 as covariates but allowing the intercepts and slope parameters of PAQ and PAQ2 tovary with the categorical variables sex, age group, and weight status.Results: ANCOVA identified a curvilinear association between VO2max and PAQ, with positive linear PAQ terms that varied for both sex andweight status but with a negative PAQ2 term of —0.39 (95% confidence interval (CI): —0.57 to —0.21) that was common for all groups in regardto age, sex, and weight status. These curvilinear (inverted U) associations suggest that the benefits of increasing PA (same dose) on VO2max isgreater when children report lower levels of PA compared to children who report higher levels of PA. These dose-response rates were alsosteeper for boys and were steeper for lean children compared to overweight/obese children.Conclusion'. Health practitioners should be aware that encouraging greater PA (same dose) in inactive and underweight children will result ingreater gains in V02max (response) compared with their active and overweight/obese counterparts.