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Background:Obesity, physical inactivity and reduced physical fitness may contribute to the rising burden of chronic diseases in China. We investigated these factors in China over a 14-year period using data from the randomized national surveys in 2000, 2005, 2010 and 2014. Methods:We conducted four national surveys among 151,656, 163,386, 154,931and 146,703 Chinese adults aged 20-59 in 2000, 2005, 2010 and 2014, respectively. Body mass index (BMI, kg/m 2 ) was used to evaluate underweight (BMI<18·5), overweight (BMI 23·0-27·5) and obesity (BMI≥27·5). Central obesity was defined as waist circumference >90 cm in men and >85 cm in women. Leisure-time physical activity (LTPA) was evaluated by whether or not the participants had completed the recommended minimum 150-min moderate or 75-min vigorous exercise per week. Indices for assessing physical fitness included forced vital capacity, resting heart rate, handgrip strength, sit and reach, and standing on one leg. Findings:The prevalence of obesity increased from 8·6% in 2000, 10·3% in 2005, and 12·2% in 2010 to 12·9% in 2014 (0·32% per year). Comparable estimates were 37·4%, 39·2%, 40·7% and 41·2% for overweight and 13·9%, 18·3%, 22·1% and 24·9% for central obesity. The corresponding upward trends per year were 0·27% and 0·78%, respectively. The prevalence of overweight, obesity and central obesity increased with age and was higher in men than women.. A simultaneous decrease was observed in the prevalence of underweight (5·4% in 2000 versus 4·6% in 2014, a downward trend of 0·06% per year). More participants met the minimum LTPA recommendation (17·2% in 2000 versus 22·8% in 2014), with the prevalence change per year being 0·33%, 0·50%, 0·37%, 0·06% for underweight, normal-weight, overweight, and obesity, respectively. Physical fitness deterioration was observed for all measures examined except resting heart rate. Interpretation:Despite increased participation in LTPA, we observed an upward trend in overweight/obesity and a decline in physical fitness in Chinese adults. Continued nationwide interventions are needed for promoting physical activity and other healthy lifestyles in China. Funding:National Physical Fitness Surveillance Center, Ministry of Science and Technology of the People's Republic of China. Introduction In recent decades, China has witnessed a rapid rise in the burden of noncommunicable diseases (NCDs). Despite differences in sampling methods and 3 diagnostic criteria, the estimated prevalence grew from 9.7% to 11.6% for type 2 diabetes, and from 15.5% to 50.1% for pre-diabetes between 2008 and 2010. 1 These diseases accounted for an estimated 80% of deaths and 70% of total disease burden in China. 2 While aging of the population is an important contributing factor, such health consequences are also likely attributed to the drastic changes in lifestyles following China's economic boom that result in obesity and physical inactivity. 3 These two factors, despite their strong correlation, have been independently linked to increased risk of ...

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IMPORTANCE Screen time has become an integral part of children's daily lives. Nevertheless, the developmental consequences of screen exposure in young children remain unclear.OBJECTIVE To investigate the screen time trajectory from 6 to 72 months of age and its association with children's development at age 72 months in a prospective birth cohort.DESIGN, SETTING, AND PARTICIPANTS Women in Shanghai, China, who were at 34 to 36 gestational weeks and had an expected delivery date between May 2012 and July 2013 were recruited for this cohort study. Their children were followed up at 6, 9, 12, 18, 24, 36, 48, and 72 months of age. Children's screen time was classified into 3 groups at age 6 months: continued low (ie, stable amount of screen time), late increasing (ie, sharp increase in screen time at age 36 months), and early increasing (ie, large amount of screen time in early stages that remained stable after age 36 months). Cognitive development was assessed by specially trained research staff in a research clinic. Of 262 eligible mother-offspring pairs, 152 dyads had complete data regarding all variables of interest and were included in the analyses. Data were analyzed from September 2019 to November 2021. EXPOSURES Mothers reported screen times of children at 6, 9, 12, 18, 24, 36, 48, and 72 months of age. MAIN OUTCOMES AND MEASURESThe cognitive development of children was evaluated using the Wechsler Intelligence Scale for Children, 4th edition, at age 72 months. Social-emotional development was measured by the Strengths and Difficulties Questionnaire, which was completed by the child's mother. The study described demographic characteristics, maternal mental health, child's temperament at age 6 months, and mental development at age 12 months by subgroups clustered by a group-based trajectory model. Group difference was examined by analysis of variance.RESULTS A total of 152 mother-offspring dyads were included in this study, including 77 girls (50.7%) and 75 boys (49.3%) (mean [SD] age of the mothers was 29.7 [3.3] years). Children's screen time trajectory from age 6 to 72 months was classified into 3 groups: continued low (110 [72.4%]), late increasing (17 [11.2%]), and early increasing (25 [16.4%]). Compared with the continued low group, the late increasing group had lower scores on the Full-Scale Intelligence Quotient (β coefficient, -8.23; 95% CI, -15.16 to -1.30; P < .05) and the General Ability Index (β coefficient, -6.42; 95% CI, -13.70 to 0.86; P = .08); the early increasing group presented with lower scores on the Full-Scale Intelligence Quotient (β coefficient, -6.68; 95% CI, -12.35 to -1.02; P < .05) and the Cognitive Proficiency Index (β coefficient, -10.56; 95% CI, -17.23 to -3.90; P < .01) and a higher total difficulties score (β coefficient, 2.62; 95% CI, 0.49-4.76; P < .05).CONCLUSIONS AND RELEVANCE This cohort study found that excessive screen time in early years was associated with poor cognitive and social-emotional development. This finding may be helpful in encouraging awareness among paren...