An increasing socioeconomic gap in childhood overweight and obesity in China

Do maternal socioeconomic status influence child overweight?

The prevalence of overweight among Chinese children under 5 years of age has been increasing steadily. Using data from China Health and Nutrition Survey (CHNS) spanning from 1991 to 2015, this study investigates the relationship between maternal employment status, maternal education level, and the prevalence of child overweight among Chinese children under 5 years old. The findings indicate that having mothers with low middle school education significantly reduces their children's body mass index z-scores (BMIZ) (p < 0.05). However, no significant association is observed between maternal education level and childhood overweight in urban areas. In rural areas, only when the maternal education level is college or above, there is a significant increase in BMIZ (p < 0.01). The impact of maternal education level on childhood obesity is influenced by household per capita income, and when household per capita income reaches a certain level, higher maternal education is negatively associated with child BMIZ. The study also reveals a significant negative association between maternal employment (p < 0.01)，average weekly working days (p < 0.01), and the BMIZ of children under 5 years of age, while the interaction effect between them is positive and significant. This study has recommended some policy interventions, by promoting parental education on child feeding and parenting, providing professional child care, and offering financial subsidies to families with children under 5.

Different Dimensions of the Home Food Environment May Be Associated with the Body Mass Index of Older Adults: A Cross-Sectional Survey Conducted in Beijing, China

OBJECTIVE

The objective of this study was to evaluate the home food environment of the elderly in Beijing and analyze its association with the body mass index (BMI) of the elderly, as well as to provide recommendations for improving the home food environment for the elderly.

METHODS

This study was conducted in Beijing, China, in 2019. The participants were 1764 elderly individuals aged 65 to 80, recruited from 12 communities through a multistage stratified random sampling method. The study involved the use of questionnaire surveys to gather data on participants' demographics, the availability of various foods in their households, and their living conditions. Socioeconomic status (SES) was evaluated based on their educational level, occupation, and income level. Height and weight measurements were taken to calculate BMI. We conducted both univariate analysis and multiple linear regression analysis to evaluate the relationship between the home food environment and BMI.

RESULTS

A total of 1800 questionnaires were distributed, of which 1775 were retrieved, resulting in a questionnaire recovery rate of 98.6%. Among these, 1764 questionnaires were deemed valid, corresponding to a questionnaire validity rate of 99.4%. The participants had a mean age of 69.7 ± 4.3 years old, over 40% of whom were overweight or obese. In terms of low-energy/high-nutrient-density foods, the most readily available items were fresh vegetables (95.6%), followed by coarse grains (94.1%), fresh fruits (90.4%), and dairy products (83.6%). Among high-energy/low-nutrient-density foods, preserved foods were the most available (51.9%), followed by salted snacks (40.6%), sugary beverages (28.2%), and fried foods (9.4%). Approximately 7.3% of participants lived alone. Elderly individuals with higher SES had a lower BMI compared to those with medium to low SES (25.9 vs. 26.5, 25.9 vs. 26.4, p < 0.05). Those living alone had a higher BMI than those who did not (27.2 vs. 26.2, p = 0.001). After controlling for potential confounding variables, older adults with high SES exhibited a BMI reduction of 0.356 kg/m2 (p = 0.001), whereas those living alone exhibited an increase in BMI of 1.155 kg/m2 (p < 0.001). The presence of preserved foods at home was linked to a BMI increase of 0.442 kg/m2 (p = 0.008).

CONCLUSION

This study underscores the significant impact of family SES, living conditions, and the availability of preserved foods on the BMI of elderly individuals.

Exploring the longitudinal associations between census division income inequality and BMI trajectories among Canadian adolescent: Is gender an effect modifier?

Background

Income inequality is a structural determinant of health linked to increased risk of overweight and obesity, although its links to the health of adolescent populations are not well understood. This study investigated the longitudinal associations between census-division-level (CD) income inequality and BMI trajectories among Canadian adolescents, and determine if these associations vary by gender.

Methods

Study data are from the Cannabis use, Obesity, Mental health, Physical Activity, Alcohol use, Smoking, and Sedentary behaviour (COMPASS) cohort of adolescents attending secondary schools in Canada. Our sample included 14,675 adolescents who were followed up across three waves of the COMPASS study (2016-2017, 2017-2018, and 2018-2019) and linked to 30 CDs. Measures of income inequality and other area-level covariates were derived and linked to COMPASS participants using data from the 2016 Canadian Census. We utilized multilevel mixed-effects linear regression modelling to quantify the associations between income inequality and BMI and test for effect modification by gender. Sensitivity analyses were run excluding those with BMI scores in the range considered overweight or obesity at baseline.

Results

Higher CD income inequality was significantly associated with higher z-transformed BMI scores (β = 0.11, 95% CI = 0.034 to 0.19). The interaction term between income inequality and time was not statistically significant, indicating that this association remained constant over time. Once stratified by gender, the association between inequality and BMI became stronger for males (β = 0.14, 95% CI = 0.060 to 0.022) and attenuated for females (β = 0.063, 95% CI = -0.047 to 0.17).

Conclusion

Attending schools in CDs with higher income inequality was associated with higher BMI scores among male but not female adolescents. Further work is needed to investigate this discrepancy and identify the structural mechanisms that mediate the relationship between inequality and adolescent health.

Re-examining the reversal hypothesis: A nationwide population-based study of the association between socioeconomic status, and NCDs and risk factors in China

Background

According to the reversal hypothesis, as a country's economic and social development progresses, the burden of NCDs and risk factors shifts from rich to poor. The aim of this research is to examine the reversal hypothesis in the Chinese setting.

Methods

Using data from the China Health and Retirement Longitudinal Study (CHARLS) in 2015, we explored whether the reversal hypothesis applies at the subnational level. Participants aged 45 years and older in 2015 were included. We examined five risk factors (smoking, heavy drinking, physical inactivity, overweight, and obesity) and three objectively measured NCDs (diabetes, hypertension, dyslipidemia). Binary logistic regressions were performed to examine outcomes across people of differing SES in provincial level, in urban and rural areas, and across generations.

Results

Nationally, SES is positively associated with heavy drinking, obesity, diabetes and dyslipidemia, whereas it is negatively associated with physical inactivity. The association between SES and smoking and hypertension was not statistically significant. Except in the cases of diabetes and dyslipidemia, we found that risk factors of all kinds were more concentrated among richer people in rural than in urban areas. Across provinces with increasing GDP per capita, a downward trend in risk factors among those with high SES compared to those with low SES could be interpreted, while the opposite trend could be interpreted with respect to the metabolic syndrome conditions. Obesity and overweight exhibited slight downward trends (in line with those for risk factors) and upward trends (in line with those for metabolic syndrome conditions), respectively.

Conclusion

We conclude that China is at a relatively early stage of 'reversal', visible with respect to risk factors. If these patterns persist over time, the trend will likely feed through to metabolic disorders which will increasingly become diseases of the poor.

Relationship of Serum Zinc Levels with Cardiometabolic Traits in Overweight and Obese Schoolchildren from Mexico City

Zinc (Zn) participates as a cofactor for many enzymes in the cellular metabolism, and its serum levels have been associated with different metabolic diseases, especially obesity (OB). Nevertheless, its associations are not clear in the children population. The objective of this study is to evaluate the association between serum Zn levels (SZn) with overweight/obesity status (OW/OB), as well as its cardiometabolic traits in a population of children in Mexico City. Anthropometrical data (body mass index z score (BMIz)), demographic variables (age and sex), and cardiometabolic traits (total cholesterol (TC), high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), triglycerides (TG), fasting plasma glucose (FPG), and insulin) were analyzed in this cross-sectional study. SZn were measured by inductively coupled plasma mass spectrometry (ICP-MS). The population included 210 children from Mexico City (girls (n = 105) and boys (n = 105)) between ages 6 and 10 years. Normal-weight (NW) schoolchildren had higher SZn concentrations (66 µg/dL; IQR: 48 to 91) compared to OW or OB schoolchildren (61 µg/dL; IQR: 45 to 76). The data showed a significant negative association between SZn and BMIz without sex exclusion (r =  - 0.181 and p = 0.009). The boy's population did not show an association between the SZn and BMIz compared to the girl's population which showed a significant negative association (r =  - 0.277 and p = 0.004). In addition, other associations were found between SZn and TC (boys (r = 0.214 and p = 0.025), LDLc (boys (r = 0.213 and p = 0.029), and TG (girls (r =  - 0.260 and p = 0.007)). Moreover, 38.6% of the total children in our population study had Zn deficiency (ZnD). NW schoolchildren had higher SZn concentrations compared to OW or OB schoolchildren. A diet low in Zn can be a factor to evaluate in the development of childhood OB in Mexico. However, further studies need to be performed on the children Mexican population to replicate and confirm our findings.

Associations between Adverse Childhood Experiences and Obesity in a Developing Country: A Cross-Sectional Study among Middle-Aged and Older Chinese Adults

BACKGROUND

The association between adverse childhood experiences (ACEs) and obesity in developing countries has been underexplored and inconsistent.

METHODS

This cross-sectional study used data of 10,054 adults aged ≥ 45 years from the China Health and Retirement Longitudinal Study. Information on 12 ACE indicators was collected via questionnaires. General obesity was defined as a body mass index (BMI) of ≥28 kg/m². Central obesity was defined as a waist circumference of ≥90 cm for males and ≥85 cm for females. Logistic and linear regression analyses were conducted to evaluate the association of ACEs with general obesity, central obesity, BMI, and waist circumference where appropriate.

RESULTS

Compared to the non-exposed group, the experience of ≥3 ACEs was significantly associated with decreased risks of general obesity (OR = 0.83, 95% CI: 0.69, 0.999), central obesity (OR = 0.88, 95% 0.77, 0.997), and smaller BMI (β = -0.27, 95% CI: -0.50, -0.04) and waist circumference (β = -0.89, 95% CI: -1.52, -0.26). Compared to the high socioeconomic status (SES) group, such associations were more evident in those with a low SES, except for central obesity.

CONCLUSION

ACEs were shown to be inversely associated with later-life obesity in China, especially in socioeconomically disadvantaged populations. The context-specific impacts reflect divergent roles of socioeconomic position in the obesity epidemic between developed and developing countries. Further investigations are needed to confirm whether physical activity could shift the direction of this association.

Socio-economic disparities in child-to-adolescent growth trajectories in China: Findings from the China Health and Nutrition Survey 1991–2015

Backgrounds

Socio-economic disparities in growth trajectories of children from low-/middle-income countries are poorly understood, especially those experiencing rapid economic growth. We investigated socio-economic disparities in child growth in recent decades in China.

Methods

Using longitudinal data on 5095 children/adolescents (7–18 years) from the China Health and Nutrition Survey (1991–2015), we estimated mean height and BMI trajectories by socio-economic position (SEP) and sex for cohorts born in 1981–85, 1986–90, 1991–95, 1996–2000, using random-effects models. We estimated differences between high (urbanization index ≥median, household income per capita ≥median, parental education ≥high school, or occupational classes I–IV) and low SEP groups.

Findings

Mean height and BMI trajectories have shifted upwards across cohorts. In all cohorts, growth trajectories for high SEP groups were above those for low SEP groups across SEP indicators. For height, socio-economic differences persisted across cohorts (e.g. 3.8cm and 2.9cm in earliest and latest cohorts by urbanization index for boys at 10 year, and 3.6cm and 3.1cm respectively by household income). For BMI, trends were greater in high than low SEP groups, thus socio-economic differences increased across cohorts (e.g. 0.5 to 0.8kg/m² by urbanization index, 0.4 to 1.1kg/m² by household income for boys at 10 year). Similar trends were found for stunting and overweight/obesity by SEP. There was no association between SEP indicators and thinness.

Interpretation

Socio-economic disparities in physical growth persist among Chinese youth. Short stature was associated with lower SEP, but high BMI with higher SEP. Public health interventions should be tailored by SEP, in order to improve children's growth while reducing overweight/obesity.

Funding

MG is supported by UCL Overseas Research Scholarship and China Scholarship Council for her PhD study. WJ is supported by a UK Medical Research Council (MRC) New Investigator Research Grant (MR/P023347/1) and acknowledges support from the National Institute for Health Research (NIHR) Leicester Biomedical Research Centre, which is a partnership between University Hospitals of Leicester NHS Trust, Loughborough University, and the University of Leicester.

Testing the talented child: Direct-to-consumer genetic talent tests in China

One controversial area of direct-to-consumer genetic testing in China is "genetic talent testing" for children. In this study, I show that while experts criticize genetic talent testing as unscientific, the persistence of genetic talent testing is not merely a product of parents' scientific illiteracy. Instead, genetic talent testing reflects parents' pragmatic use of technology in response to the parenting pressures in contemporary China. Parents see the results of genetic talent testing as offering an advantage for their children when combined with the intensive parenting strategy of precision education. Drawing on the sociology of testing, I argue how genetic talent testing in China is a product of broader concerns about population quality and can potentially reshape how parents imagine quality children through the theory of multiple intelligences. My study of this "off label" use of direct-to-consumer genetic testing also suggests that scientists need to broaden their imagination of potential misuses of their technologies.

Magnitude of Stunting and Associated Factors among Adolescent Students in Legehida District, Northeast Ethiopia

BACKGROUND

Undernutrition including stunting particularly at an adolescent stage was not emphasized by various intervention strategies in the Ethiopian context. Assessing the magnitude and potential risk factors of undernutrition is thus helpful for policymakers to design appropriate intervention strategies. Hence, this study was aimed at assessing the magnitude of stunting and associated factors among adolescent students in Legehida district, Northeast Ethiopia.

METHODS

A school-based cross-sectional study was conducted among 424 adolescent students from February 15th to March 15th, 2018. A stratified sampling followed by a simple random sampling technique was used to select the study participants. A pretested, structured, and self-administered questionnaire was used to collect the required data. Height was measured by using a portable stadiometer and the height-for-age (HFA) z-score was calculated as an indicator of stunting. SPSS version 25 and WHO AnthroPlus software were applied to analyze the data. A multivariable logistic regression analysis was performed to identify factors associated with adolescent stunting. Statistical significance was determined at a p value of <0.05 and association was described by using an odds ratio at a 95% confidence interval.

RESULTS

A total of 406 adolescent students (with a response rate of 95.7%) participated in the study. The magnitude of stunting among adolescent students in this study was 24.9% (95% CI: 24.6%-35.3%).

CONCLUSIONS

Stunting among adolescent students was significantly associated with being male [AOR = 2.1; 95% CI: 1.73-5.90], meal frequency (<3/day) [AOR = 4.6; 95% CI: 2.61-8.24], infrequent handwashing practice [AOR = 3.6; 95% CI: 1.30-9.40], absence of latrine facility (AOR = 5.51; 95% CI: 3.03-9.9), and consumption of unsafe water [AOR = 2.8; 95% CI: 1.35-6.19]. Hence, conducting routine nutrition screenings and assessments, promotion of proper food intake, and emphasis on nutrition education and counseling are needed to be strengthened.

Confirmatory factor analysis of the Children's Eating Behaviour Questionnaire in a Chinese urban preschooler sample

Background

Understanding young children's eating behaviours is vital to childhood obesity prevention. However, the widely used Children's Eating Behaviour Questionnaire (CEBQ) has not been validated in Chinese young children. Thus, the present study aimed to assess the validity of the CEBQ in a Chinese urban sample of preschool children.

Methods

Participants included 389 mothers with preschool children residing in Beijing, China. Confirmatory factor analysis was conducted, and measurement invariance between child genders was evaluated.

Results

The modified 8-factor structure of the CEBQ exhibited acceptable model fit in our sample, and no measurement bias against any gender was observed. The associations between the CEBQ factors and child age showed that desire to drink, emotional overeating, and emotional undereating significantly decreased with age, but food responsiveness increased with age. The relation between child BMI and the CEBQ factors provided convergent validity for the CEBQ.

Conclusions

Our study supported the validity of the CEBQ as a measurement tool for examining preschool children's eating behaviours in a Chinese urban sample.

Educational attainment of offspring and obesity among older adults in China

The study focuses on the role of adult offspring's educational attainment in obesity among older adults in China and investigates age and birth cohort heterogeneities in the educational effect. Using the longitudinal data from the 1993-2015 China Health and Nutrition Survey (CHNS), we employed three-level mixed-effects models and conducted sex-stratified analyses to examine the effects of co-resident offspring's education on body mass index (BMI), overweight, waist circumference (WC), and abdominal obesity among older people born before 1956. After controlling for confounding factors, the overall results showed inverted U-shaped educational gradients in BMI-based outcomes for males and positive gradients for females. The effect of education on WC exhibited an inverted U-shaped pattern for both sexes, but no significant effect on abdominal obesity was found among the overall population. However, further analyses of interaction effects indicated considerable age and cohort variations in the educational effects on obesity outcomes. Offspring's schooling was positively associated with obesity among earlier birth cohorts; Among more recent birth cohorts, especially among females, the educational effects were reversed, and disparities in obesity outcomes across education categories strengthened with age. These findings imply that offspring's education appears to gradually exert a protective role against obesity among Chinese older adults in successive cohorts.

The association of quality of life and personality characteristics with adolescent metabolic syndrome: a cohort study

BACKGROUND

An increased prevalence of adolescent metabolic syndrome (MS) is associated with adulthood cardiovascular diseases. This study aimed to explore the potential relationship of quality of life (QoL) and personality traits with adolescent MS.

METHODS

A total of 1961 participants from Chongqing with an average age of 11.68 years old from a cohort study established in 2014 and followed up through 2019 were included. QoL information, Eysenck's personality questionnaire and MS components were collected.

RESULTS

A higher QoL domain score of physical activity ability (PAA) was a protective factor for both MS and MS score (all P < 0.01), which was mainly negatively correlated with the MS components of central obesity, diastolic blood pressure (DBP) and triglyceride levels, as well as positively correlated with high density lipoprotein cholesterol (HDL-C) level. The total QoL score was negatively correlated with triglyceride levels and positively correlated with DBP (all P < 0.01). High extraversion personality score was a protective factor against adolescent MS (P = 0.04) and MS score (P < 0.05), which were mainly negatively correlated with the MS components of waist circumference, systolic blood pressure and TGs, and positively correlated with HDL-C (all P ≤ 0.01).

CONCLUSIONS

QoL score and extraversion personality score were independent protective factors against both MS prevalence and MS score, suggesting that community intervention to improve the QoL and psychological health of children are essential.

The association of quality of life and personality characteristics with adolescent metabolic syndrome: a cohort study

Background

An increased prevalence of adolescent metabolic syndrome (MS) is associated with adulthood cardiovascular diseases. This study aimed to explore the potential relationship of quality of life (QoL) and personality traits with adolescent MS.

Methods

A total of 1961 participants from Chongqing with an average age of 11.68 years old from a cohort study established in 2014 and followed up through 2019 were included. QoL information, Eysenck’s personality questionnaire and MS components were collected.

Results

A higher QoL domain score of physical activity ability (PAA) was a protective factor for both MS and MS score (all P < 0.01), which was mainly negatively correlated with the MS components of central obesity, diastolic blood pressure (DBP) and triglyceride levels, as well as positively correlated with high density lipoprotein cholesterol (HDL-C) level. The total QoL score was negatively correlated with triglyceride levels and positively correlated with DBP (all P < 0.01). High extraversion personality score was a protective factor against adolescent MS (P = 0.04) and MS score (P < 0.05), which were mainly negatively correlated with the MS components of waist circumference, systolic blood pressure and TGs, and positively correlated with HDL-C (all P ≤ 0.01).

Conclusions

QoL score and extraversion personality score were independent protective factors against both MS prevalence and MS score, suggesting that community intervention to improve the QoL and psychological health of children are essential.

Epidemiology and determinants of obesity in China

Obesity has become a major public health issue in China. Overweight and obesity have increased rapidly in the past four decades, and the latest national prevalence estimates for 2015-19, based on Chinese criteria, were 6·8% for overweight and 3·6% for obesity in children younger than 6 years, 11·1% for overweight and 7·9% for obesity in children and adolescents aged 6-17 years, and 34·3% for overweight and 16·4% for obesity in adults (≥18 years). Prevalence differed by sex, age group, and geographical location, but was substantial in all subpopulations. Strong evidence from prospective cohort studies has linked overweight and obesity to increased risks of major non-communicable diseases and premature mortality in Chinese populations. The growing burden of overweight and obesity could be driven by economic developments, sociocultural norms, and policies that have shaped individual-level risk factors for obesity through urbanisation, urban planning and built environments, and food systems and environments. Substantial changes in dietary patterns have occurred in China, with increased consumption of animal-source foods, refined grains, and highly processed, high-sugar, and high-fat foods, while physical activity levels in all major domains have decreased with increasing sedentary behaviours. The effects of dietary factors and physical inactivity intersect with other individual-level risk factors such as genetic susceptibility, psychosocial factors, obesogens, and in-utero and early-life exposures. In view of the scarcity of research around the individual and collective roles of these upstream and downstream factors, multidisciplinary and transdisciplinary studies are urgently needed to identify systemic approaches that target both the population-level determinants and individual-level risk factors for obesity in China.

Different Effects of Leucine Supplementation and/or Exercise on Systemic Insulin Sensitivity in Mice

Objective

Obesity-related diseases such as diabetes, hypertension, dyslipidemia, and cardiovascular diseases have increased due to the obesity epidemic. Early intervention for obesity through lifestyle and nutrition plays an important role in preventing obesity-related diseases. Therefore, the purpose of this study is to explore the role of leucine and exercise in adiposity, systemic insulin resistance, and inflammation to provide theoretical and guiding basis for the early prevention and treatment of obesity.

Methods

C57BL/6J male mice were randomly divided into HFD or LFD-fed mice group. After 9 weeks, glucose tolerance test (GTT) was performed to detect their systemic insulin sensitivity. Starting from week 10, mice were divided into eight groups and treated with moderate exercise or/and 1.5% leucine. At week 13, systemic insulin sensitivity was detected by GTT. At week 14, mice were dissected to analyze adiposity and inflammation.

Results

In LFD mice, exercise significantly increased systemic insulin sensitivity by increasing GLUT4 expression in the muscle and decreasing adiposity through increasing AMPK phosphorylation in adipose tissue. In HFD mice, the simultaneous intervention of exercise and leucine increases systemic insulin sensitivity by reducing liver and adipose tissue inflammation via decreasing NF-κB p65 phosphorylation, and increasing the expression of adiponectin in adipose tissue.

Conclusion

There are different mechanisms underlying the effects of exercise and leucine on insulin resistance and inflammation in LFD-fed mice or HFD-fed mice.

Association between parental socioeconomic status and offspring overweight/obesity from the China Family Panel Studies: a longitudinal survey

OBJECTIVE

To examine the association between parental socioeconomic status (SES) and the risk of offspring overweight/obesity and the changes of the association that occur as children grow older.

DESIGN

We used data from the nationally representative longitudinal survey of the China Family Panel Studies of 2010 and its three follow-up waves in 2012, 2014 and 2016.

PARTICIPANTS

A total of 6724 children aged 0-15 years old were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

Average household income and paternal and maternal education levels were used as SES indicators. Logistic regression model for panel data was used to examine the associations between SES indicators and child overweight/obesity. A restricted cubic spline linear regression model was used to estimate body mass index (BMI) trajectories with child growth across parental SES levels.

RESULTS

Compared with the lowest education level (primary school or less), the ORs for fathers who had completed junior high school, senior high school and junior college or higher were 0.85 (95% CI 0.75 to 0.97), 0.77 (95% CI 0.64 to 0.92) and 0.72 (95% CI 0.55 to 0.93), respectively. The corresponding ORs for mothers were 0.76 (95% CI 0.67 to 0.86), 0.59 (95% CI 0.47 to 0.72) and 0.45 (95% CI 0.34 to 0.60), respectively. A negative association between parental education and offspring overweight/obesity was observed in the first 10 years but not in children 11-15 years old. BMI differences across parental education levels emerged from birth and widened before 6-7 years old, but decreased before adolescence. High average household income was related to a low risk of offspring overweight/obesity but not when parental education level was adjusted for.

CONCLUSION

High parental education levels were associated with a low risk of offspring overweight/obesity, especially before adolescence. Effective approaches need to be adopted in early childhood to reduce socioeconomic differences in overweight/obesity.

Dietary patterns and their associations with overweight/obesity among preschool children in Dongcheng District of Beijing: a cross-sectional study

BACKGROUND

Few studies investigated the associations between dietary patterns and overweight/obesity among Chinese preschool children. Thus, the study aims to explore dietary patterns and their associations with overweight/obesity among preschool children in the Dongcheng District of Beijing.

METHODS

With a stratified proportionate cluster sampling, the study included 3373 pairs of preschool children and their guardians. Children's weight and height were measured by school nurses, and their food and beverage consumption frequencies were reported by guardians via a food frequency questionnaire. Children's age, gender, physical activity time, and sedentary time, as well as their parents' highest level of educational attainment, occupation, weight, and height were also collected. Dietary patterns were identified through exploratory factor analysis. Among these identified dietary patterns, the one with the largest factor score was defined as the predominant dietary pattern for each child. The associations between predominant dietary patterns and overweight/obesity were tested by two-level random-intercept logistic models with cluster-robust standard errors.

RESULTS

Four dietary patterns, i.e., a "Sugar-sweetened beverage (SSB) and snack" pattern, a "Chinese traditional" pattern, a "Health conscious" pattern, and a "Snack" pattern, were identified. Among the children, 21.02% (95% CI: 19.68 to 22.43%) were predominated by the "SSB and snack" pattern, 27.78% (95% CI: 26.29 to 29.32%) by the "Chinese traditional" pattern, 24.90% (95% CI: 23.47 to 26.39%) by the "Health conscious" pattern, and 26.30% (95% CI: 24.84 to 27.81%) by the "Snack" pattern. After controlling for potential confounders, the "SSB and snack" pattern characterized by fresh fruit/vegetable juice, flavored milk drinks, carbonated drinks, flavored fruit/vegetable drinks, tea drinks, plant-protein drinks, puffed foods, fried foods, and Western fast foods was associated with a higher risk of overweight/obesity (OR: 1.61, 95% CI:1.09 to 2.38), compared with the "Chinese traditional" pattern.

CONCLUSIONS

The preference for dietary patterns with high energy density but low nutritional value was prevalent among preschool children in the Dongcheng District of Beijing. Comprehensive measures to simultaneously reduce consumption of SSBs and unhealthy snacks among preschool children should be taken urgently to address the childhood obesity problem in China, particularly in metropolises.

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.

Associations of outdoor activity and screen time with adiposity: findings from rural Chinese adolescents with relatively low adiposity risks

Background

Whether and to what extent outdoor activity and screen time are relevant to adiposity among rural adolescents remain largely unknown as most of relevant evidence was generated from high-income countries and urban areas. This study aimed to investigate associations of outdoor activity and screen time with adiposity among early adolescents living in rural southwest China.

Methods

In this cross-sectional study, seventh graders (n = 2264) were recruited from 10 middle schools of a rural county. Overweight and obesity was assessed using adolescents’ body mass index and waist circumference. Adolescents’ outdoor activity and screen time were measured using self-reported daily time spending on outdoor activity, watching TV, playing video games, and computers on weekdays and weekends, respectively.

Results

The prevalence of overweight/obesity and high waist circumferences were 8.0 and 4.9% and were higher among those from one-child families and with parents having high school or higher education and whose fathers were not farmers. Adolescents who did not have ≥1 h outdoor activity on weekdays were more likely to be overweight/obese (OR: 1.86, 95% CI: 1.30, 2.66) and have high waist circumferences (OR: 2.22, 95%CI: 1.39, 3.57). Adolescents who had > 2 h screen time on weekends were more likely to have high waist circumferences (OR: 2.08, 95% CI: 1.14, 3.80). Lack of outdoor activity and excessive screen time also showed synergistic effects on overweight/obesity (OR: 1.93. 95% CI: 1.15, 3.24) and high waist circumferences (OR: 3.02, 95% CI: 1.54, 5.94).

Conclusions

Lack of outdoor activity and excessive screen time were relevant to adiposity among rural Chinese adolescents even when the obesity prevalence was low. Efforts to promote active lifestyles may help prevent rural adolescents from losing their advantage in the era of the global obesity epidemic.

Developmental trajectories of adolescent overweight/obesity in China: socio-economic status correlates and health consequences

OBJECTIVES

During recent decades, China has experienced a rapid growth in economy and also in prevalence of childhood obesity. Given the great importance of adolescence overweight/obesity for future health and given the relative lack of longitudinal studies on adolescent obesity in developing countries, particularly in China, in this study, we aimed to explore the potential growth trajectories of overweight/obesity among Chinese adolescents and to further examine socio-economic status predictors and health consequences of these growth trajectories.

STUDY DESIGN

This study is a longitudinal study.

METHODS

The data were from four waves of panel data from the China Family Panel Studies (CFPS 2010, 2012, 2014, and 2016). For the present study, children aged 10 to 12 years from the baseline 2010 sample were selected (N = 1685), among whom 1388 were reinterviewed in 2012, 1172 in 2014, and 941 in 2016. We retained a final sample of 800 who had at least three waves of body mass index (BMI) data (i.e. final N = 800). Generalized growth mixture modeling was used as the major analytical strategy.

RESULTS

We found three different types of overweight/obesity developmental trajectories for these Chinese adolescents, namely a stably normal class, a decreased risk class, and a chronically overweight/obese class. Moreover, we found that higher family income was associated with a lower probability of getting into the chronically overweight/obese class for urban adolescents but with a higher probability of getting into the same class for rural adolescents. Lastly, the adolescents classified in the chronically overweight/obese group reported significantly lower levels of self-rated health.

CONCLUSIONS

There were heterogeneous growth trajectories of adolescent overweight/obesity in China. Sustained overweight/obesity during adolescence was predicted by lower family income in urban China but by higher family income in rural China. More targeted and regionalized interventions for childhood overweight/obesity in China should be considered.

The Socioeconomic Inequality in Increment of Caries and Growth among Chinese Children

BACKGROUND

This study aimed at assessing socioeconomic inequalities in the increment of dental caries and growth among preschool Chinese children, and to assess the best predictor of socioeconomic inequality for each of these conditions.

METHODS

This is a longitudinal population-based study. The sample data included preschool children living in three cities of the Liaoning Province, China. At baseline, 15 kindergartens with 1111 participants were included and dropped to 772 with a response rate of 70% at follow-up. Mean ages at baseline and follow-up were 50.82 and 60.55 months, respectively. Median follow-up time was 10.12 months. Data were collected through structured questionnaire, oral examination and anthropometric measurement. The questionnaire collected information on sex, age, family income, mother's education and children's dietary habits. The numbers of decayed, missing and filled teeth (DMFT) was used to indicate dental caries. Weight- and height-for-age z-scores were calculated using the WHO Growth Standard. Multilevel analysis was used to assess the association between baseline socioeconomic position and each of dental caries and child's growth.

RESULTS

Mother's education was negatively associated with increments of DMFT. Family income was not significantly associated with DMFT in the fully adjusted model. The association persisted after accounting for other socioeconomic and dietary factors. Higher income was positively related to an increase in the weight-for-age z-score. The relationship between income and changes in the height-for-age z-score was positive and significant in the second highest income group.

CONCLUSIONS

Mother's education appeared to be the strongest predictor of increments of dental caries. Only income was significantly associated with an increase in children's weight and height.

Artificial neural network optimizes self-examination of osteoporosis risk in women

Objective

This study aimed to investigate the application of an artificial neural network (ANN) in optimizing the Osteoporosis Self-Assessment Tool for Asians (OSTA) score.

Methods

OSTA score was calculated for each female participant that underwent dual-energy X-ray absorptiometry examination in two hospitals (one in each of two Chinese cities, Harbin and Ningbo). An ANN model was built using age and weight as input and femoral neck T-score as output. Osteoporosis risk screening by joint application of ANN and OSTA score was evaluated by receiver operating characteristic curve analysis.

Results

Nearly 90% of women with dual-energy X-ray absorptiometry-determined femoral neck osteoporosis were ≥60 years old. The ANN with age and weight as input and OSTA score both identified osteoporosis, with respective accuracy rates of 78.8% and 78.3%. However, both methods failed to identify osteoporosis in women < 60 years old. Compared with OSTA score alone, combined use of the two tools increased the rate of osteoporosis recognition among women > 80 years old.

Conclusions

OSTA score-mediated osteoporosis risk screening should be restricted to women ≥60 years old. Joint application of ANN and OSTA improved osteoporosis risk screening among Chinese women > 80 years old.

Child Overweight and Obesity in Shanghai, China: Contextualizing Chinese Socioeconomic and Gender Differences

PURPOSE

Childhood overweight and obesity is on the rise in China and in Chinese cities in particular. The aim of this study is to explore the extent of income differences in childhood overweight in Shanghai, China, and examine demographic, social, and behavioral explanations for these differences.

METHODS

Using the 2014 Child Well-Being Study of Shanghai, China-a survey that included extensive contextual information on children and their families in China's most populous city, prevalence rates and adjusted odds ratios of child overweight and obesity at age 7 were calculated by income tercile controlling for a wide variety of sociodemographic variables.

RESULTS

District aggregate income increases the odds of child overweight/obesity, but only for boys. In contrast, rural hukou status was associated with lower odds of overweight/obesity for girls.

CONCLUSIONS

Boys at age 7 are more likely to be overweight and obese than girls. District income further increases this likelihood for boys, while rural hukou status decreases this likelihood for girls, suggesting that preferences for boys and thinness ideals for girls may play a role in the income patterning of childhood overweight and obesity.

Perceived Discrimination, Screen Use, and BMI Among Rural-to-Urban Migrant Children in China: Evidence from a Nutrition Transition Context

Discrimination promotes sedentary behavior and obesity among Western adults. The obesogenic impact of discrimination has yet been examined in developing countries. Participants were 1755 seventh grade rural-to-urban migrant students in the first three waves (2013-2016) of China Education Panel Survey-Junior High Cohort. Latent growth curve models evaluated associations of perceived origin-based discrimination with intercepts and slopes for BMI and screen use trajectories over a 3-year period. Most migrant students came from families of low socioeconomic status. Around 20% of the migrant students reported origin-based discrimination at school. After adjusting for covariates, origin-based discrimination was positively associated with intercepts of TV watching (b = 0.18, p < .001) and internet use (b = 0.24, p < .001), but was not associated with either the intercept or slope of BMI. Perceived discrimination increases screen use for Chinese migrant children, though its contribution to BMI growth is unclear. As the nutrition transition penetrates deeper into lives of all social strata, future studies need to monitor whether perceived discrimination may emerge as an important source of social disparity in obesity in China.

Double burden of malnutrition among children under 5 in poor areas of China

OBJECTIVE

The aim of this study was to investigate the nutritional status and its risk factors among children under 5 years, with special focus on the coexistence of under and over nutrition in population level.

METHODS

We enrolled 6,570 children under 5 years among 26 counties in poor areas of China. Prevalences of malnutrition (stunting, underweight, wasting, overweight) were calculated. Overweight was evaluated using two indicators-weight for height Z score (WHZ) and body mass index for age Z score (BAZ), and results were compared.

RESULTS

The total prevalence of malnutrition was 19.2%. The prevalence of stunting and overweight were as high as 8.4% and 8.8%, respectively. The BAZ-estimated prevalence of overweight was 9.9%, which was higher than the WHZ-estimated prevalence (p<0.001). Children older than 12 months age, within a minority group, with a caregiver of illiteracy/primary education level were significantly associated with stunting in multilevel regression models (p<0.05). Children younger than 24 months age and boys were significantly associated with overweight (p<0.05).

CONCLUSIONS

Stunting and overweight were coexisted in surveyed areas. In conclusion, BAZ tended to overestimate the overweight prevalence compared with WHZ. While with the raising problem of childhood overweight, stunting should still be on the agenda for the poor areas in China. To improve children's nutritional status in poor areas of China, caregivers with children at high risk of malnutrition should be guided for healthy feeding practices.

Body weight regulation, socioeconomic status and epigenetic alterations

Obesity is a complex disease which has reached epidemic dimensions. Thus, prevention of excessive weight gain and associated metabolic and cardiovascular diseases has to start as early in life as possible. The impact of epigenetic mechanisms on the regulation of genes involved in obesity is increasingly recognized. On the other hand, it is well known that socioeconomic factors influence the risk for obesity. These factors can also have an impact on epigenetic gene regulation. There is increasing body of evidence that several factors and interventions addressing extragenetic causes of obesity may not only improve individual health, but also the health of future generations by epigenetic alterations. Our current understanding of epigenetic changes has shown that many of them are potentially reversible, i.e. by physical exercise, by pharmacological treatment, by environmental factors or nutrition, or even by influencing socioeconomic factors, which might have impact on improving health in future generations by avoiding epigenetic dysregulation. In this review we present the current state of the art with regard to the interplay between social determinants, weight status and epigenetic alterations.

Trends in urban/rural inequalities in cardiovascular risk bio-markers among Chinese adolescents in two decades of urbanisation: 1991-2011

BACKGROUND

China has seen rapid socio-economic changes and epidemiological transitions in the last few decades. Previous studies often fail to examine how wider macro-level forces contribute to changes in health inequality among its population in China. This study aims to examine urban/rural inequalities in cardiovascular (CVD) risks biomarkers among Chinese adolescents in two decades from 1991 to 2011 during the process of China's rapid urbanisation.

METHODS

Data were drawn from a nationwide longitudinal dataset of the China Health and Nutrition Survey (CHNS) (Sweeps 1991, 1993, 1997, 2000, 2004, 2006, 2009 and 2011). Children aged between 12 and 18 years (Boys: n = 3472; Girl: n = 3155) were included. A dynamic urbanisation index was created for each community (village or neighbourhood) based on community-level data that can reveal the heterogeneity within and across places and capture dimensions of social, economic and physical characteristics of urban living over time and space. Linear multilevel modeling analyses (Level 1: Occasions; Level-2: Individuals; Level-3: Households; Level-4: Communities) were performed on outcomes of CVD risk biomarkers including anthropometric measures and blood pressure.

RESULTS

After adjustment for age, maternal education and household income per capita, cardiovascular (CVD) risk biomarkers increase among Chinese adolescents during 1991 to 2011. Urbanisation tends to have an independent and positive impact on body mass index (BMI) and waist circumference for boys but not for girls. Positive interaction effect between urbanisation index and survey years for waist circumference was observed for girls (0.005; 95% confidence interval [CI], 0.002, 0.007; p < 0.01): time trends become greater when areas become more urbanized. For blood pressure, when areas become more urbanized the trends for boys become decreased (- 0.005; 95% CI, - 0.009, - 0.002; p < 0.01 for systolic blood pressure and - 0.003; 95% CI, - 0.006, - 0.001; p < 0.05 for diastolic blood pressure).

CONCLUSION

Chinese adolescents are experiencing an upward trend of cardiovascular (CVD) risks in last two decades. Its rapid urbanisation appears to further increase urban/rural inequalities in CVD risks, especially for boys from less urbanised areas and girls from more urbanised areas, which may contribute to the development of cardiovascular disease (CVD) in adulthood. It is relevant to inform policy making process to target specific vulnerable groups. Given China's urbanisation is strongly influenced by the state, there is a possibility for policy intervention to reduce inequality during the process of China's planned urbanisation.

Clustering of unhealthy lifestyle behaviours and associations with perceived and actual weight status among primary school children in China: A nationally representative cross-sectional study

Few studies have focused on clustering of unhealthy lifestyle behaviours among primary school children and potential associations with perceived and actual weight status. An index was constructed from adding up 13 unhealthy behaviours measured by survey responses. Multilevel linear regressions were used to analyse associations between child personal characteristics, perceived and actual weight status with the unhealthy lifestyle index among 11,157 children in primary schools across China. Parental and area factors were also taken into account, including education, weight status, physical activity, urban/rural and area socioeconomic circumstances. The unhealthy lifestyle index normally distributed, with 84.5% of children reporting between 2 and 6 unhealthy behaviours. Boys reported more unhealthy behaviours compared with girls (coefficient 0.32, 95%CI 0.26 to 0.37) and children in urban areas had fewer unhealthy behaviours than their rural counterparts (-0.29, 95%CI -0.56 to -0.03). An interaction revealed stronger 'protective' effects of living in cities for girls than boys, which were not explained by differences in child overweight/obesity. More unhealthy behaviours were characteristic of children in more affluent areas, and of those born to mothers and/or fathers with lower educational attainment. Children who perceived themselves as overweight or underweight both scored higher on the unhealthy lifestyle index. Unhealthy behaviours that could increase the risk of childhood obesity are common among Chinese primary school children, particularly among boys in cities, those in more affluent areas and with parents with lower education. There was no effect of actual weight status on number of unhealthy behaviours. Perceived, but not actual weight status, was also a significant correlate of unhealthy behaviours. Clustering of unhealthy lifestyle behaviours that could increase the risk of childhood obesity are common among Chinese primary school children, particularly among boys in cities, those in more affluent areas and with parents with lower education. Perceived, but not actual weight status, was also a significant correlate of unhealthy lifestyle. This has important implications for public health because understanding clustering of unhealthy lifestyle behaviours can be used to assist in the development of targeted obesity prevention initiatives.

A prospective cohort study to investigate parental stress and child health in low-income Chinese families: protocol paper

INTRODUCTION

Chronic stress has adverse effects on health. Adults and children from low-income families are subject to multiple sources of stress. Existing literature about economic hardship mostly focuses on either adults or children but not both. Moreover, there is limited knowledge on the relationship between parental generalised stress and child health problems. This study aims to explore the bidirectional relationship between parental stress and child health in Chinese low-income families and to identify other modifiable factors influencing this relationship.

METHODS AND ANALYSIS

This prospective cohort study will sample 254 low-income parent-child pairs and follow them up for 24 months with assessments at three time points (baseline, 12 and 24 months) on parental stress, health-related quality of life (HRQOL) and child health and behaviour using both subjective measures and objective physiological parameters. This study will collect data using standardised measures on HRQOL and behaviours of children as well as on HRQOL, mental health and stress levels of parents along with physiological tests of allostatic load and telomere length. The mediating or moderating effect of family harmony, parenting style and neighbourhood conditions will also be assessed. Data will be analysed using latent growth modelling and cross-lagged path analysis modelling to examine the bidirectional effect of parental stress and child health over time. Mediation and moderation analysis will also be conducted to examine the mechanism by which the variables relate.

ETHICS AND DISSEMINATION

This study was approved by the institutional review board of the University of Hong Kong-the Hospital Authority Hong Kong West Cluster, reference no: UW 16-415. The study findings will be disseminated through peer-reviewed publications and international conferences.

TRIAL REGISTRATION NUMBER

NCT03185273; Pre-results.

Obesity, body image, and its impact on children's eating and exercise behaviors in China: A nationwide longitudinal study

Body image seems to mediate the association between obesity and health behaviors as well as weight control attempts. We examined the distribution of children's body image by demographic characteristics and their subsequent associations with eating, exercise, and weight change. Child body image and health behaviors from the China Health National Survey 2000-2011 were assessed at baseline and in follow-up for 6- to 17-year-old children during 2000-2011 using mixed models. There was a large discrepancy between children's actual weight status (overweight: 16.9%) vs. self-rated body image (fat: 2.4% in 2011). Less than 1% of children desired a fat body; girls were more likely to want to be thin (52.5% vs. 40.9%) than boys. About 11% of children needed to lose weight in order to be at their desired baseline. During follow-up, those needing weight loss to be as desired were more likely to attempt dieting to change their weight (OR, 95% CI=1.9, 1.1-3.5 in boys; 1.7, 1.1-2.5 in girls) and less likely to feel they had enough physical activity (OR, 95% CI=0.5, 0.4-0.7 in boys; 0.6, 0.5-0.9 in girls), although their weight gain had been significantly higher than those having consistent self and desired body images (β [SE]=0.4 [0.1] in boys; 0.2 [0.1] in girls, all p<0.05). However, no significant difference was shown in subsequent health behaviors among overweight children by body image discrepancy. The discrepancy in self vs. desired body image motivated children to change their obesity-related health behaviors among non-overweight children in China.

The Changing Pattern of Nutrition Intake by Social Class in Contemporary China, 1991-2011

OBJECTIVES

To explore the changing pattern of nutrition intake by social class in contemporary China.

METHODS

We defined social class in 2 ways. The first definition was based on employment, and the second definition was based on per capita household income levels. We used China Health and Nutrition Survey data from 1991 to 2011 to show the changes in the relation between social class and nutrition intake.

RESULTS

The relation between social class and nutrition intake in China changed significantly within the 2 decades. For example, in the early 1990s, the lowest social class (defined by employment or income) had more caloric intake than did the highest social class; 20 years later, however, the relation reversed, and the lowest social class consumed significantly fewer calories.

CONCLUSIONS

China has seen a great reversal in its social class-nutrition relationship since the early 1990s. Our study calls for wider recognition that insufficient consumption of food and nutrition is increasingly an issue for people in the lower social classes in China.

High protein intake along with paternal part-time employment is associated with higher body fat mass among girls from South China

PURPOSE

Protein intake has been suggested to be associated with body composition among western children. Our aim was to determine whether protein intake is associated with body composition among Chinese children and to investigate whether parental socioeconomic status modifies these associations.

METHODS

Cross-sectional data were collected from the baseline survey of an ongoing population-based prospective open cohort study conducted in 2013. In this survey, 2039 children in South China were recruited using cluster random sampling. Information of 1704 children (47% girls), aged 7-12 years from three primary schools (42 classes), on diet and anthropometry was included finally. Their daily protein intake was obtained by 3-day 24-h dietary recalls. Skinfold thickness, body height, and weight were measured to calculate percent body fat (%BF), fat mass index (FMI), and fat-free mass index (FFMI). Parental characteristics were collected by questionnaires.

RESULTS

Among girls, protein intake was positively associated with %BF and FMI [estimate (SE) for %BF: 0.007 (0.003), p = 0.04; for FMI: 0.092 (0.002), p = 0.03], adjusted for pubertal stage, breast-feeding, maternal overweight, carbohydrate intake, energy intake, and physical activity level. Furthermore, there was interaction between paternal occupation and the relations of dietary protein with %BF and FMI (p _{for interaction} ≤ 0.04). None of the associations between protein intake and %BF, FMI, or FFMI was found among boys.

CONCLUSIONS

Our data indicate that school-aged girls, but not boys, living in South China with higher dietary protein intake might have higher body fat mass, which could be modified by paternal occupation.

Contextual influences affecting patterns of overweight and obesity among university students: a 50 universities population-based study in China

Background

Many studies have examined childhood and adolescent obesity, but few have examined young adults and the effect of their home and current living environments on prevalence rates. The present study explores contextual factors affecting overweight and obesity among university students in China and, in particular, focuses on how the SES–obesity relationship varies across different geographical contexts.

Methods

Participants were 11,673 students, who were identified through a multistage survey sampling process conducted in 50 universities. Individual data was obtained through a self-administered questionnaire, and contextual variables were retrieved from a national database. Multilevel logistic regression models were used to examine urban and regional variations in overweight and obesity.

Results

Overall the prevalence of overweight and obesity in the study sample was 9.5% (95% CI 7.7, 11.3%). After controlling for individual factors, both attributes of the home location (regional GDP <gross domestic product> per capita and rurality) and the current university location (city population) were found to be important, thus suggesting that the different origins of students affect current levels of obesity. At the individual level, while students with more financial resources were more likely to be obese, the extent of this relationship was highly dependent upon area income and city size.

Conclusion

The results of this study add important insights about the role of contextual factors affecting overweight and obesity among young adults and indicate a need to take into account both past as well as present environmental influences when considering the role of contextual factors in models of the nutrition transition.

The Association between Family and Parental Factors and Obesity among Children in Nanchang, China

BACKGROUND

With rapid economic development in China, traditional patterns of health behaviors are changing, concurrent with a rise in childhood obesity. While the home environment and parenting behaviors are modifiable factors that could be targeted for intervention, little is known about their relationship with children's health behaviors. Therefore, the purpose of this study was to investigate the relationship between obesity and home and parenting factors in Chinese children.

METHODS

A cross-sectional survey was conducted in Nanchang, China in 2013 with caregivers (N = 470) of a child between the ages of 2 and 10 years. Regression analyses were conducted to determine risk factors for childhood obesity.

RESULTS

Obesity prevalence (21.7%) did not differ by demographic variables. Eight physical activity, nutrition, and sedentary variables had significant relationships to obesity status. Logistic regression analysis revealed three significant predictors of obesity: the number of days the family eats meals together (odds ratio = 0.84, 95% CI 0.73-0.96) and parental home computer use time (odds ratio = 0.83, 95% CI 0.72-0.96) were related to lower levels of obesity, while parental television time (odds ratio = 1.25 95% CI 1.07-1.47) was related to higher levels of obesity.

CONCLUSION

The prevalence of obesity among children is high in Nanchang. Family and environmental risk factors are significantly related to obesity.

Patterns and Determinants of Double-Burden of Malnutrition among Rural Children: Evidence from China

Chinese children are facing dual burden of malnutrition—coexistence of under-and over-nutrition. Little systematic evidence exists for explaining the simultaneous presence of under-and over-nutrition. This study aims to explore underlying mechanisms of under-and over-nutrition among children in rural China. This study used a nationwide longitudinal dataset of children (N = 5,017) from 9 provinces across China, with four exclusively categories of nutritional outcomes including under-nutrition (stunting and underweight), over-nutrition (overweight only including obesity), paradox (stunted overweight), with normal nutrition as reference. Multinomial logit models (Level-1: occasions; Level-2: children; Level-3: villages) were fitted which corrected for non-independence of observations due to geographic clustering and repeated observations of individuals. A mixture of risk factors at the individual, household and neighbourhood levels predicted under-and over-nutrition among children in rural China. Improved socioeconomic status and living in more urbanised villages reduced the risk of stunted overweight among rural children in China. Young girls appeared to have higher risk of under-nutrition, and the risk decreased with age more markedly than for boys up to age 5. From age 5 onwards, boys tended to have higher risk of under-nutrition than girls. Girls aged around 12 and older were less likely to suffer from under-nutrition, while boys’ higher risk of under-nutrition persisted throughout adolescence. Children were less likely to suffer from over-nutrition compared to normal nutrition. Boys tended to have an even lower risk of over-nutrition than girls and the gender difference widened with age until adolescence. Our results have important policy implications that improving household economic status, in particular, maternal education and health insurance for children, and living environment are important to enhance rural children’s nutritional status in China. Investments in early years of childhood can be effective to reduce gender inequality in nutritional health in rural China.

Socioeconomic determinants of childhood obesity among primary school children in Guangzhou, China

Background

Socioeconomic inequalities in childhood obesity prevalence differ according to a country’s stage of nutrition transition. The aim of this study was to determine which socioeconomic factors influence inequalities in obesity prevalence in Chinese primary school children living in an urban setting.

Methods

We assessed obesity prevalence among 9917 children aged 5–12 years from a stratified random sample of 29 state-funded (residents) and private (migrants) schools in Guangzhou, China. Height and weight were objectively measured using standardised methods and overweight (+1 SD < BMI-for-age z-score ≤ +2 SD) and obesity (BMI-for-age z-score > +2 SD) were defined using the World Health Organisation reference 2007. Socioeconomic characteristics were ascertained through parental questionnaires. Generalised Linear Mixed Models with schools as a random effect were used to compare likelihood of overweight/obesity among children in private, with public schools, adjusting for child age and sex, maternal and paternal BMI and education level, and household per-capita income.

Results

The prevalence of overweight/obesity was 20.0 % (95 % CI 19.1 %–20.9 %) in resident compared with 14.3 % (95 % CI 13.0 %–15.4 %) in migrant children. In the adjusted model, the odds of overweight/obesity remained higher among resident children (OR 1.36; 1.16–1.59), was higher in boys compared with girls (OR 2.56; 2.24–2.93), and increased with increasing age (OR 2.78; 1.95–3.97 in 11–12 vs 5–6 year olds), per-capita household income (OR 1.27; 1.01–1.59 in highest vs lowest quartile) and maternal education (OR 1.51; 1.16–1.97 in highest vs lowest). Socioeconomic differences were most marked in older boys, and were only statistically significant in resident children.

Conclusions

The socioeconomic gradient for childhood obesity in China is the reverse of the patterns seen in countries at more advanced stages of the obesity epidemic. This presents an opportunity to intervene and prevent the onset of social inequalities that are likely to ensue with further economic development. The marked gender inequality in obesity needs further exploration.