The life-course changes in muscle mass using dual-energy X-ray absorptiometry: The China BCL study and the US NHANES study.

BACKGROUND: Sarcopenia is an important indicator of ill health and is linked to increased mortality and a reduced quality of life. Age-associated muscle mass indices provide a critical tool to help understand the development of sarcopenia. This study aimed to develop sex- and age-specific percentiles for muscle mass indices in a Chinese population and to compare those indices with those from other ethnicities using the National Health and Nutrition Examination Survey (NHANES) data. METHODS: Whole-body and regional muscle mass was measured by dual-energy X-ray absorptiometry (DXA) in participants of the China Body Composition Life-course (BCL) study (17 203 healthy Chinese aged 3-60 years, male 48.9%) and NHANES (12 663 healthy Americans aged 8-59 years, male 50.4%). Age- and sex-specific percentile curves were generated for whole-body muscle mass and appendicular skeletal muscle mass using the Generalized Additive Model for Location Scale and Shape statistical method. RESULTS: Values of upper and lower muscle mass across ages had three periods: an increase from age 3 to a peak at age 25 in males (with the 5th and 95th values of 41.5 and 66.4 kg, respectively) and age 23 in females (with the 5th and 95th values of 28.4 and 45.1 kg, respectively), a plateau through midlife (30s-50s) and then a decline after their early 50s. The age at which muscle mass began to decline was 52 years in men with the 5th and 95th percentile values of 43.5 and 64.6 kg, and 51 years in women with the 5th and 95th percentile values of 31.6 and 46.9 kg. Appendicular skeletal muscle mass decreased earlier than whole body muscle mass, especially leg skeletal muscle mass, which decreased slightly after age 49 years in both sexes. In comparison with their US counterparts in the NHANES, the Chinese participants had lower muscle mass indices (all P < 0.001) and reached a muscle mass peak earlier with a lower muscle mass, with the exception of similar values compared with adult Mexican and White participants. The muscle mass growth rate of Chinese children decreased faster than that of other races after the age of 13. CONCLUSIONS: We present the sex- and age-specific percentiles for muscle mass and appendicular skeletal muscle mass by DXA in participants aged 3-60 from China and compare them with those of different ethnic groups in NHANES. The rich data characterize the trajectories of key muscle mass indices that may facilitate the clinical appraisal of muscle mass and improve the early diagnosis of sarcopenia in the Chinese population.

Genetically proxied vitamin B12 and homocysteine in relation to life course adiposity and body composition.

OBJECTIVE: Observational studies explore the association between vitamin B12 and obesity. However, causality is not reflected by such observations. We performed a bi-directional Mendelian randomization (MR) study to elucidate the causal relationship of vitamin B12 and homocysteine (Hcy) with life course adiposity and body composition. METHODS: Two-sample MR analysis was conducted. Independent genetic variants associated with vitamin B12 and Hcy from large-scale genome-wide association studies (GWASs) were utilized as genetic instruments, and their causal effects on five life course adiposity phenotypes (birth weight, body mass index (BMI), childhood BMI, waist circumference, waist-to-hip ratio) and three body compositions (body fat mass, body fat-free mass, body fat percentage) were estimated from UK Biobank, other consortia, and large-scale GWASs. The inverse variance weighting (IVW, main analysis), bi-directional MR, and other six sensitivity MR analyses were performed. RESULTS: Genetically proxied higher vitamin B12 concentrations were robustly associated with reduced BMI (Beta = -0.01, 95% confidence interval (CI) -0.016 to -0.004, P = 7.60E-04), body fat mass (Beta = -0.012, 95%CI -0.018 to -0.007, P = 1.69E-05), and body fat percentage (Beta = -0.005, 95%CI -0.009 to -0.002, P = 4.12E-03) per SD unit by IVW and other sensitivity analyses. Stratification analysis showed that these results remained significant in females and at different body sites (all P < 0.05 after Bonferroni correction). Bi-directional analyses showed no reverse causation. CONCLUSIONS: This study provides strong evidence for the causal effect of vitamin B12 on adiposity. This gives novel clues for intervening obesity in public health and nutrition.

Spatial-temporal trends in global childhood overweight and obesity from 1975 to 2030: a weight mean center and projection analysis of 191 countries.

BACKGROUND: The geographic information science-based interactive map provided good prospects for the public health to study disease prevalence. The purpose of this study is to understand global spatial-temporal trends of childhood overweight and obesity and underlying causes help formulating intervention strategies. METHODS: This multiple cross-sectional study included data on childhood overweight and obesity prevalence, gross national income per capita, and urbanization rate for 191 countries from 1975-2016. Autoregressive integrated moving average model, standard deviational ellipse model and mixed-effects models were used to explore spatial-temporal trends of childhood overweight and obesity and associations with gross national income per capita and urbanization rate. RESULTS: Globally, childhood overweight and obesity rate would reach 30.0% in 2030 (boys: 34.2%, girls: 27.4%). By 2030, it would reach 58.3% in middle- and high-income countries and 68.1% in Western Pacific region. Spatial-temporal trendline for childhood overweight and obesity in 1975-2030 exhibited a "C" shape, migrating from 1975 (15.6。E, 24.6。N) to 2005 (10.6。E, 21.7。N), then to 2030 (14.8。E, 17.4。N). The trendline for urbanization rate was also an irregular "C", and the turning point appeared five years earlier than childhood overweight and obesity. CONCLUSIONS: Globally, childhood overweight and obesity prevalence will continue to increase. Its weight mean center migrated from western countries to Asia and Africa following economic development.

Prevalence of hypertension and its associations with body composition across Chinese and American children and adolescents.

BACKGROUND: The age of onset of hypertension (HTN) is decreasing, and obesity is a significant risk factor. The prevalence and racial disparities in pediatric HTN and the association between body composition and blood pressure are insufficiently studied. This study aimed to evaluate the prevalence of HTN in Chinese and American children and adolescents and to assess the relationship between various body composition indices and HTN. METHODS: Seven thousand, five hundred and seventy-three Chinese and 6239 American children and adolescents aged 8-18 years from the 2013-2015 China Child and Adolescent Cardiovascular Health study and the 2011-2018 National Health and Nutrition Examination Surveys were analyzed. Blood pressure and body composition (fat and muscle) were measured by trained staff. The crude prevalence and age-standardized prevalence rate (ASPR) of primary HTN and its subtypes [isolated systolic hypertension (ISH) and isolated diastolic hypertension (IDH)] were calculated based on 2017 American Academy of Pediatrics guidelines. Multivariable-adjusted linear regression coefficients and odds ratios (ORs) were calculated to assess the associations of body composition indicators with HTN, ISH and IDH. RESULTS: The ASPR of HTN was 18.5% in China (CN) and 4.6% in the United States (US), whereas the obesity prevalence was 7.4% and 18.6%, and the population attributable risk of HTN caused by overweight and obesity was higher in the US than in CN. Increased fat mass, muscle mass and body fat percentage mass were associated with a higher risk of HTN in both countries. The percent of muscle body mass had a protective effect on HTN and ISH in both countries [HTN (CN: OR = 0.83, 95% CI = 0.78-0.88; US: OR = 0.72, 95% CI = 0.64-0.81); ISH (CN: OR = 0.87, 95% CI = 0.80-0.94; US: OR = 0.71, 95% CI = 0.62-0.81)], and the protective effect was more common among children and adolescents with high levels of physical activity. CONCLUSIONS: The burden of HTN in Chinese children and adolescents was substantial and much greater than that in the US, and the contribution of obesity to HTN was higher in the US than in CN. Augmenting the proportion of muscle mass in body composition has a protective effect against HTN in both populations. Optimizing body composition positively influences blood pressure in children and adolescents, particularly those with high-level physical activity. Video abstract (MP4 149982 KB).

Association of Macronutrients Intake with Body Composition and Sarcopenic Obesity in Children and Adolescents: A Population-Based Analysis of the National Health and Nutrition Examination Survey (NHANES) 2011-2018.

The association of macronutrients intake with body composition and sarcopenic obesity remains uncertain in children and adolescents. We aimed to explore the association between macronutrients intake and body composition, especially sarcopenic obesity, in children and adolescents residing in the United States. The study utilized data from 5412 participants aged 6-17 years who attended NHANES between 2011 and 2018. Body composition was assessed using DXA, and nutrient intake was based on 24-h recall. Multivariable linear regression and multinomial logistic regression were used. The unweighted prevalence of sarcopenic obesity was 15.6%. A higher percentage of energy (5 %E) from fat was inversely associated with muscle mass but positively associated with fat mass and sarcopenic obesity. Substituting carbohydrate (5 %E) with fat decreased muscle mass by 0.03 (95% CI 0.01 to 0.06) but increased fat mass by 0.03 (95% CI 0.01 to 0.06) and increased the prevalence of sarcopenic obesity by 254% (95% CI 15% to 487%). Replacing protein intake with fat intake also increased the OR of sarcopenic obesity (OR, 2.36 [95% CI 1.18 to 3.18]). In conclusion, a high-fat diet, coupled with low carbohydrate/protein intake, is associated with sarcopenic obesity among children and adolescents. The change in children's diet towards a healthy diet with low fat composition may help prevent sarcopenic obesity. However, randomized clinical trials or longitudinal studies are needed to further validate our findings.

Difference of glucose and lipid metabolism abnormalities and body fat between the Chinese and USA teenagers.

Background: Comparing body fat and the effect of body fat on metabolic abnormalities in Chinese and USA teenagers may provide clues for the early prevention and control of cardiovascular disease (CVD). We aimed to compare the prevalence of glucose and lipid metabolism abnormalities, body fat amount and distribution, and the effect of body fat on glucose and lipid metabolism in Chinese and US teenagers. Methods: We included 5424 Chinese teenagers (48.5% male) from the China Child and Adolescent Cardiovascular Health (CCACH) study and 8704 USA teenagers (55.6% male) from the USA National Health and Nutrition Examination Survey (NHANES). Blood lipid, blood glucose, and body fat indicators were obtained using the same standardised measurements. Results: The prevalence of dyslipidaemia in Chinese teenagers was of those in the USA (hypercholesterolaemia = 3.5% vs 7.4%; high low-density lipoprotein cholesterol (LDL-C) = 3.6% vs 5.0%; low high-density lipoprotein cholesterol (HDL-C) = 9.9% vs 14.3%; hypertriglyceridaemia = 3.7% vs 10.1%) (P < 0.05). However, with the increase in body mass index (BMI), the prevalence of high LDL-C increased more in Chinese than in US teenagers, even exceeding them in the obese group (2.7% in non-overweight to 9.7% in overweight group in China, P < 0.05; 3.5% in non-overweight to 6.5% in the obese group in the USA, P < 0.05). The prevalence of impaired fasting glucose was higher in China than in the USA (28.0% vs 17.5%, P < 0.05). Besides, Chinese adolescents are more likely to accumulate fat in the abdomen, and the per-unit fat increase would bring a higher risk of dyslipidaemia in Chinese boys than in USA boys. Conclusions: Dyslipidaemia was more prevalent in US teenagers than in Chinese teenagers, but with the increase in BMI, the prevalence of high LDL-C increased more in Chinese than in US teenagers. Impaired fasting glucose (IFG) was significantly more prevalent in China than in the USA. The unfavoured body fat and higher risk of body fat on metabolic disorders in Chinese teenagers suggest that Chinese teenagers should pay more attention to the adverse effect of body fat on metabolic abnormalities.

Association and potential mediators between socioeconomic status and childhood obesity in China:findings from a national cohort study / 《全球健康杂志（英文）》

Objective:Socioeconomic status(SES)is associated with childhood obesity,but the underlying factors remain unknown.This study aimed to identify mediators that may explain SES disparities in childhood obesity in China.Methods:Nationally representative longitudinal data from the China Education Panel Survey of 11 019 chil-dren(13.03±0.79)collected from 2013-2014 to 2016-2017 academic years.Overweight/obesity was de-fined using Chinese national body mass index cut-points.Principal component analysis was used to con-vert the four SES indicators(maternal and paternal education,and occupation)into one comprehensive vari-able.Mediation analysis for SES disparities in childhood obesity was conducted using structure equation models.Results:The prevalence of overweight/obesity was 12.8％,and was higher in boys than in girls(17.8％vs.7.6％,P＜0.001)at baseline.Among boys,relative risk(RR)of obesity was 1.23(95％CI:1.09 to 1.40,P＜0.001)for per unit change in SES.There was no significant association between obesity and SES among girls.Mediation analyses showed that among boys,birth weight,being the only child in the family and children's self-perceived weight status mediated 70.0％of the effects of SES on obesity.No mediation effect was detected in girls.Conclusions:Chinese boys are more likely to be overweight or obese than girls.SES may impact childhood obesity through birth weight,being the only child in the family and children's self-perceived body weight status in boys,but not in girls.More attention should be made to address childhood obesity in high SES families among boys.Interventions targeting at these mediators are needed.

The associations of muscle mass with glucose and lipid metabolism are influenced by body fat accumulation in children and adolescents.

Objective: To evaluate the prevalence of hyperglycemia and dyslipidemia among different body composition and investigate the associations of body composition indicators, especially the muscle mass, with glucose and lipids metabolism in children and adolescents. Methods: This nationwide cross-sectional study included 8,905 children and adolescents aged 6 to 18 years. All participants underwent dual-energy x-ray absorptiometry and their blood-concentrated glucose and lipids (including TC, TG, LDL-C and HDL-c) were measured. Mixed model, hierarchical analysis, and piecewise regression were used to study the effect of body composition indicators, especially the muscle mass, on glucose and lipids metabolism. Results: The greatest prevalence of high total cholesterol (TC, 6.9% and 6.9%) and high triglyceride (22.3% and 6.6%) was found in both boys and girls with high muscle mass and high fat mass, and girls with high muscle mass and high fat mass also had the highest prevalence of hyperglycemia (7.1%). After fat stratification, higher muscle mass was associated with lower odds of hyperglycemia (OR = 0.62; 95%CI: 0.46,0.84; P = 0.002) and muscle mass was inversely associated with TC (ß = -0.07; 95%CI: -0.12,-0.03; P < 0.001) in boys with normal fat mass, but high muscle mass was not significantly associated with hyperglycemia and TC in high-fat-mass group (P = 0.368 and 0.372). Conclusions: The body composition phenotype of high muscle and high fat mass have the highest prevalence of dysglycemia and dyslipidemia. Higher muscle mass was associated with a lower risk of hyperglycemia and TC levels in individuals only with normal fat mass.

Time trends and disparities in combined overweight and obesity prevalence among children in China.

This study aims to examine the trends and disparities in the combined prevalence of overweight and obesity among children in China by regions and specific groups over the last 30 years. PubMed, Wanfang, CNKI, VIP database, official websites of national governments and professional institutions/associations were systematically searched, for related reports and studies published up until December 2021. Reports based on nationally representative survey data were also examined and included. In mainland China, overweight and obesity decreased in pre-school children (≤6 years old) and increased in school-aged children (7-18 years old) between 2010 and 2013 to 2015 and 2017, but long-term trends predict future increases in both groups. The prevalence of overweight and obesity in primary school students in Hong Kong dropped from 21.4% in 2007-2008 to 17.6% in 2016-2017. In Macao, the prevalence of overweight and obesity in children aged 6-18 years was reported by age stratification; the lowest and highest prevalence was 13.4%, 29.3% and 9.2%, 21.7% for boys and girls in latest survey in 2015, respectively. The prevalence of overweight and obesity in primary, middle and high school students in Taiwan dropped from 28.2%, 27.1% and 31.1% in 2010 to 26.7%, 25.2% and 26.7% in 2013, respectively. Furthermore, in mainland China, the prevalence in rural left-behind boys and girls was 10.7% and 7.0%, respectively, in 2011, and the prevalence among migrant pre-school children was about 5.0% around 2010. In summary, the prevalence of overweight and obesity in school-aged children has increased in mainland China and Macao, but decreased in Hong Kong and Taiwan prior to 2017. The projections suggest that the highest prevalence of overweight and obesity in pre-school children will be in rural children in the future. These factors need to be considered when formulating and implementing national policies and programmes to fight overweight and obesity.

Health consequences of obesity and projected future obesity health burden in China.

OBJECTIVE: This study examined the effects of overweight/obesity on mortality and morbidity outcomes and the disparities, time trends, and projected future obesity health burden in China. METHODS: Cohort studies that were conducted in China and published in English or Chinese between January 1, 1995, and July 31, 2021, were systematically searched. This study focused on overweight/obesity, type 2 diabetes mellitus (T2DM), hypertension, cardiovascular diseases, metabolic syndrome, cancers, and chronic kidney disease. RESULTS: A total of 31 cohorts and 50 cohort studies reporting on mortality (n = 20) and morbidities (n = 30) associated with obesity met study inclusion criteria. Overall, BMI was nonlinearly (U-shaped) associated with all-cause mortality and linearly associated with risks of T2DM, cardiovascular diseases, hypertension, cancer, metabolic syndrome, and chronic kidney disease. In 2018, among adults, the prevalence of overweight/obesity, hypertension, and T2DM was 51.2%, 27.5%, and 12.4%, respectively. Their future projected prevalence would be 70.5%, 35.4%, and 18.5% in 2030, respectively. The projected number of adults having these conditions would be 810.65 million, 416.47 million, and 217.64 million, respectively. The urban-rural disparity in overweight/obesity prevalence was projected to shrink and then reverse over time. CONCLUSIONS: The current health burden of obesity in China is high and it will sharply increase in coming years and affect population groups differently. China needs to implement vigorous interventions for obesity prevention and treatment.

Interactions between Self-Perceived Weight Status and Lifestyle Behaviors and Their Associations with Childhood Obesity: Results from the Childhood Obesity Study in China Mega-Cities.

This study investigated the interactions between self-perceived weight status and lifestyle behaviors, and their associations with childhood obesity among school children. Methods: Cross-sectional study data from a nationwide sample of 3258 participants (aged 8-15 years old) during 2015-2017 were used. Self-perceived weight status and lifestyle factors (dietary intake and physical activity) were assessed using self-administered questionnaires. Multivariable mixed-effects models tested the effect of interactions between weight self-perception and behavioral factors on overweight and obesity (ow/ob). Results: Overall ow/ob prevalence based on BMI was 30.9% (38.5% for boys, 23.0% for girls). Based on self-perceived weight status, ow/ob prevalence was 37.7% (35.8% for boys, 39.7% for girls). 41.2% of boys and 25.9% of girls underestimated their actual weight status. The interaction between self-perceived weight status and meat consumption was associated with ow/ob in boys, while the interaction between self-assessed weight status and protein foods and sedentary lifestyle were associated with ow/ob in girls. The attributable proportions of these three factors were 39.8%, 48.2%, and 34.6%, respectively. Conclusions: The self-perceived weight status was different from their actual weight status in children. The interactions between self-perceived weight status and lifestyle behaviors were associated with ow/ob. Health promotion programs that empower children to have appropriate self-awareness of weight status, eating, and physical activity behaviors need to be developed and implemented.

Associations of sleep duration with childhood obesity:findings from a national cohort study in China / 《全球健康杂志（英文）》

Objective:Examine effect of sleep duration on children's risk of overweight and obesity;and study associations between activities in the last hour before bedtime and sleep outcomes(sleep duration,sleep quality,and sleep onset latency).Methods:Children's data were recruited using a questionnaire survey from a nationally representative sample of children(n=10 279)in China in 2013-2016.Mixed-effects models were used to test associations among variables stratified by sex.Results:Sleep duration was positively associated with BMI in boys(p=0.04,P=0.021).Girls with short sleep durations(＜8 h/d)tended to have higher BMI values than those with normal sleep durations(8-9 h/d)(β=0.12,P=0.063).The top three activities were playing electronic devices(Factor 1),doing homework,and reading(combined as Factor 2).Factors 1 and 2 were both significantly associated with sleep duration(β=0.17,P＜0.001;β=-0.26,P＜0.001,respectively).Conclusion:Sleep duration seems to affect BMI in Chinese children.Using electronic devices and reading before bedtime influenced sleep duration.Good bedtime habits and sleep duration can help weight management in children.

Effectiveness of a multifaceted intervention for the improvement of nutritional status and nutrition knowledge of children in poverty-stricken areas in Shaanxi Province,China / 《全球健康杂志（英文）》

Objectives:Compare the differences between the intervention and control groups in changes of primary outcomes(body mass index[BMI]and waist-to-height ratio[WHtR])and secondary outcomes(nutrition knowledge of children and parents),from baseline to the 6-and 12-month follow-ups;examine the associations of changes in nutrition knowledge of children and their parents with children's changes in BMI and WHtR.Data sources:Data collected from four schools in two poverty-stricken counties in northern Shaanxi Province in 2020-2021.Methods:A multifaced intervention program targeted children(promoting healthy diet and nutrition education)and their parents(promoting nutrition knowledge)was conducted in the interventional group.Four schools,with two in each group,were randomly allocated to the intervention or control group,with 814 eligible children aged 7.1 to 12.8 years.The control group conducted myopia promotion.Differences in changes of BMI and WHtR between groups were compared with t-test.Mixed-effects model was used to examine the associations between changes in nutrition knowledge of children and parents with changes in children's BMI and WHtR.Results:At the 6-month follow-up,the difference in changes in BMI between the intervention and control groups was 0.4 kg/m 2(P＜0.001).At the 12-month follow-up,the difference in changes in BMI and WHtR between intervention and control groups was 0.1 kg/m2(P＜0.001)and 0.01 kg/m2(P＜0.001).In the intervention group,the nutrition knowledge awareness rate of children increased from 16.9％(69/409)at baseline to 21.3％(87/409)at 6-month,and 22.7％(93/409)at 12-month.The awareness rate of nutrition knowledge of parents also fluctuated,from 5.6％(23/409)to 6.6％(27/409)and 5.4％(22/409).However,the difference in changes in nu-trition knowledge between intervention and control groups was non-significant.The 6-month follow-up changes in children's nutrition knowledge scores were negatively associated with changes in BMI in girls(β=-0.26,95％confidence interval[CI]:-0.38 to-0.14,P＜0.001),while positively associated with changes in WHtR in boys(β=0.003,95％CI:-0.0002 to 0.005,P=0.035).The 12-month follow-up changes in children's nutrition knowledge scores were positively associated with changes in children's WHtR(β=0.003,95％CI:0.0004 to 0.01,P=0.018).Conclusions:The intervention strategies did not reduce the BMI and WHtR of children,and the nutrition knowl-edge of children and parents increased after the intervention in intervention group.Changes in nutrition knowl-edge of children and their parents are associated with changes in children's BMI or WHtR.Interventions with a new focus on obesity are needed to help improve children's nutritional status in poverty-stricken areas in Shaanxi Province of China.

Coding Variants are Relevant to the Expression of Obesity-Related Genes for Pediatric Adiposity.

OBJECTIVE: Heredity has a remarkable effect on obesity in an obesogenic environment. Despite the numerous genetic variants that contribute to obesity-related traits, none has been identified in Chinese children. This study aimed to identify novel variants associated with childhood obesity in China. METHODS: Promising single-nucleotide variants were obtained using whole-exome sequencing from 76 children who had obesity and 74 children with normal weight, and their associations with obesity-related traits in an additional 6,334-child cohort were investigated. The effects of the genome-wide significant (P < 5E-8) variants on the expression of the implicated genes in blood and adipose tissue were then depicted using transcriptome sequencing. RESULTS: Two coding variants associated with obesity with genome-wide significance were identified: rs1059491 (P = 2.57E-28) in SULT1A2 and rs189326455 (P = 8.98E-12) in MAP3K21. In addition, rs1059491 was also significantly associated with several obesity traits. Transcriptome sequencing demonstrated that rs1059491 and rs189326455 were expression quantitative trait loci relevant to the expression levels of several obesity-related genes, such as SULT1A2, ATXN2L, TUFM, and MAP3K21. CONCLUSIONS: This work identified two coding variants that were significantly associated with pediatric adiposity and were expression quantitative trait loci for obesity-related genes. This study provides new insights into the pathophysiology of Chinese childhood obesity.

Health policy and public health implications of obesity in China.

China has experienced many drastic social and economic changes and shifts in people's lifestyles since the 1990s, in parallel with the fast rising prevalence of obesity. About half of adults and a fifth of children have overweight or obesity according to the Chinese criteria, making China the country with the highest number of people with overweight or obesity in the world. Assuming that observed time trends would continue in the future, we projected the prevalence of and the number of people affected by overweight and obesity by 2030, and the associated medical costs. The rising incidence of obesity and number of people affected, as well as the related health and economic consequences, place a huge burden on China's health-care system. China has made many efforts to tackle obesity, including the implementation of relevant national policies and programmes. However, these measures are inadequate for controlling the obesity epidemic. In the past decade, China has attached great importance to public health, and the Healthy China 2030 national strategy initiated in 2016 provides a historical opportunity to establish comprehensive national strategies for tackling obesity. China is well positioned to explore an effective model to overcome the obesity epidemic; however, strong commitment and leadership from central and local governments are needed, as well as active participation of all related society sectors and individual citizens. TRANSLATION: For the Chinese translation of the paper see Supplementary Materials section.

Eating-out behaviors, associated factors and associations with obesity in Chinese school children: findings from the childhood obesity study in China mega-cities.

PURPOSE: Eating-out and prevalence of obesity/overweight have been rising rapidly in China in the past two decades due to social economic developments. This study examined Chinese school children's eating-out behaviors and associated factors, including their association with obesity during a 3-year follow. METHODS: Data were collected from 3313 primary and middle school children aged 7-16 years in five mega-cites across China in 2015, 2016 and 2017, in an open cohort study. Eating-out behaviors were assessed using questionnaire survey. The Chinese age-sex-specific body mass index (BMI) cutoffs were used defining child overweight/obesity (combined) and obesity; central obesity was defined as WHtR ≥ 0.48. Mixed effect models examined associations between child eating-out behaviors and BMI, overweight and obesity in this longitudinal data, adjusting for other covariates. RESULTS: About 80.1% of the children reported having eaten out ≥ 1 times/week over the past 3 months; 46.7% and 70.9% chose Western- and Chinese-style food when ate out, respectively. Meanwhile, 29.8% of them were overweight/obese, 12.7% were obese and 20.1% had central obesity. Child eating-out behaviors were positively associated with parents' eating-out behaviors (p < 0.05). Boys were more likely to choose Western-style food than girls (OR 1.27; 95% CI 1.09-1.48) when eating out. Compared to non-overweight/obese children, those being overweight/obese at baseline were less likely to eat out dining on Western-style food during the follow-up. CONCLUSION: Eating-out is common among school children in major cities in China, but with considerable differences across groups. Children's weight status was associated with eating-out behaviors.

Parent-child resemblance in BMI and obesity status and its correlates in China.

OBJECTIVE: Examine mother-son, mother-daughter, father-son and father-daughter resemblance in weight status, and potential modifying effects of socio-demographic and childcare characteristics. DESIGN: Cross-sectional study. SETTING: School. PARTICIPANTS: 1973 school-age children and their parents from five mega-cities across China in 2017. RESULTS: Pearson correlation coefficients (r) for BMI of father-son, father-daughter, mother-son and mother-daughter pairs were 0·16, 0·24, 0·26 and 0·24, respectively, while their weighted kappa coefficients (k) were 0·09, 0·14, 0·04 and 0·15, respectively. Children aged 6-9 years (r ranged from 0·30 to 0·35) had larger BMI correlation with their parents than their counterparts aged 10-14 years or 15-17 years (r ranged from 0·15 to 0·24). Children residing at home (r ranged from 0·17 to 0·27) had greater BMI correlations with their parents than children residing at school/other places. BMI correlation coefficients were significant if children were mainly cared for by their mothers (r ranged from 0·17 to 0·29) but non-significant if they were mainly cared for by others. Only children who ate the same meal as their parents 'most times' (r ranged from 0·17 to 0·27) or had dinner with their parents 'at most times' (r ranged from 0·21 to 0·27) had significant BMI correlation with their parents. Similarly, children who had dinner with their parents 'most times' but not 'sometimes,' had significant BMI correlation coefficients. CONCLUSIONS: Parent-child resemblance in weight status was modest and varied by child age, gender, primary caregiver, whether having similar food or dinner with parents in China.

Growing fast food consumption and obesity in Asia: Challenges and implications.

It is widely believed that better access to fast food (FF) outlets increases FF consumption and thus the risk of obesity; yet, thus far, there are limited results to support this conclusion in Asian countries. A recent study by Hall and his colleagues (in press) examined the cross-sectional relationship between FF restaurant density and the likelihood of being overweight or obese among 1388 female Filipino migrant workers living in Macao, China. It found that FF restaurant density within a 0.5-mile buffer zone around one's home was significantly associated with a 7% increase (95% CI: 1%-14%) in the odds of being overweight or obese in this population. Based on these findings, the authors suggested improving access to healthy foods as one of the means to fight the obesity epidemic. The current article examines literature 1) on the relationship between obesity, FF consumption, and access to FF outlets; 2) on different measures of access to FF outlets; 3) on potential confounders and effect modifiers such as neighborhood deprivation and transportation; and 4) on challenges and implications for researchers and policymakers. Considering the growing consumption of FF and obesity rates in many countries especially in developing countries, it is important to regulate the FF industry and help consumers improve their related knowledge and behaviors. We also recommend that government policies abate obesogenic environments and thus curb the obesity epidemic in the future.

A 3-year Longitudinal Study of Pocket Money, Eating Behavior, Weight Status: The Childhood Obesity Study in China Mega-Cities.

The associations between children's pocket money and their eating behaviors and weight status have not been examined using longitudinal data in China. Examined child and parental factors associated with children's pocket money, and longitudinal effects of pocket money on children's eating behaviors and weight status. Data were collected in 2015, 2016, and 2017 from 3261 school-age children and their parents in mega-cities across China (Beijing, Shanghai, Nanjing, Xi'an, Chengdu). Children's weight, height, and waist circumference were measured; pocket money and eating behaviors were self-reported. Mixed effect models were used. Older children received more pocket money than younger children (incident rate ratio (IRR) = 1.21, 95% confidence interval (CI): 1.15, 1.26). Fathers gave their children more pocket money than mothers did (IRR = 1.22, 95% CI: 1.16, 1.30). Children with fathers having ≥ college education received more pocket money than the others did (IRR = 1.20, 95% CI: 1.04, 1.40). Some nutrition-related parenting behaviors and attitude were also associated with children's pocket money. Compared with children receiving no weekly pocket money, those having 1-10 or 10-30 or >30-yuan weekly pocket money were 12.0-136% more likely to consume unhealthy foods and were 66-132% more likely to be overweight or obese. Some child and parental factors were associated with children's pocket money, which increased risks of having unhealthy eating behaviors and being overweight and obese.