Nutrition and physical activity related school environment/policy factors and child obesity in China: a nationally representative study of 8573 students in 110 middle schools

Ecological system theory and community participation to promote healthy food environments for obesity and non-communicable diseases prevention among school-age children

OBJECTIVES

To implement and evaluate the effectiveness of the community participatory program between school and family based on ecological system theory and participatory action research. The intervention covers three levels at the individual, family and school levels and involves educating students and parents by using technology, reducing sedentary behaviours, increasing exercise and changing to healthy food environments at school and at home.

DESIGN

A quasi-experimental design was used in this study.

SETTING

Public primary school in Thailand.

SUBJECTS

The participants in the study included 138 school-age children in grades 2-6 with their parents/guardians. The control group consisted of 134 school-age children at a school of the same size with their parents/guardians.

RESULTS

Results show that nutritional status was significantly improved within the experimental group (P value = 0·000) and between groups during follow-up (P value = 0·032). Students' knowledge about obesity and non-communicable chronic diseases (NCD) prevention, as well as physical activity and exercise behaviours, in the experimental group was significantly higher than that in the control group (P value = 0·000 and 0·044, respectively). Parents' perceptions of child obesity and family modelling behaviours in the experimental group were also significantly higher than that in the control group; P value = 0·013 and 0·000, respectively).

CONCLUSION

The community participation program was found to be successful. Not only students, families and schools improved health behaviours and healthy food environments at home and school, but the students' long-term nutritional status also improved.

Longitudinal effects of school policies on children's eating behaviors and weight status: findings from the childhood obesity study in China megacities

OBJECTIVES

To examine longitudinal effects of school policies on children's weight status and eating behaviors, and study how these effects may vary by children's age, sex, and baseline weight status in China.

METHODS

Data were collected in 2015, 2016, and 2017 in an open cohort of 3298 children aged 6-17, their parents, and schools in five large cities across China (Beijing, Shanghai, Xi'an, Nanjing, and Chengdu). Children's weight, height, and waist circumference were measured, and their eating behaviors were self-reported. The 1691 children with such repeated measures in ≥ two waves were included in longitudinal data analysis with mixed effects models, testing the associations.

RESULTS

Having school vicinity food stall policy was associated with less frequent consumption of fast food (β = -0.14, p < 0.01) and snack (β = -0.84, p < 0.01). More significant associations were found between school policies and unhealthy eating behaviors for girls and children aged 6-11 than their counterparts. Among children without overweight or central obesity at baseline, having school cafeteria food policy was associated with lower risks for overweight and obesity (OR = 0.33, 95% CI: 0.17-0.63) and central obesity (OR = 0.47, 95% CI: 0.26-0.85). This existed for girls, but not for boys. School vicinity food stall policy was associated with lower BMI (β = -0.20, 95% CI: -0.37, -0.03) among all children and in girls (β = -0.28, 95% CI: -0.50, -0.05) without overweight at baseline.

CONCLUSIONS

School policies could reduce children's unhealthy eating behaviors and obesity risk in megacities in China. Children's age, sex, and baseline weight status modify the effects. School policies are important to fight the growing childhood obesity epidemic.

A 3-year longitudinal study of the association of physical activity and sedentary behaviours with childhood obesity in China: The childhood obesity study in China mega-cities

OBJECTIVES

Examine school children's physical activity (PA) and sedentary behaviours (SB) during 2015 to 2017 in China, and study their associations with children's weight status and relevant gender differences.

METHODS

This open cohort study included students from five major cities (Beijing, Shanghai, Xi'an, Nanjing, and Chengdu) across China. Data were collected from students in 2015, 2016, and 2017 (n = 5535) and from their parents and school personnel. Children's weight, height, and waist circumference were measured. SB and PA factors were evaluated using questionnaires. Mixed-effects models examined the relationship between weight status and PA-/SB-associated factors using this longitudinal data.

RESULTS

These children had high rates of obesity (12.4%, 95% CI 11.6%-13.3%) and central obesity (28.1%, 95% CI 26.9%-29.3%) during 2015 to 2017. Boys were more likely to have obesity than girls (16.5% vs 8.4%, respectively) as well as centrally obesity (36.3% vs 19.8%, respectively) and spent more time in screen viewing than girls (hours/week ± SD: 2015, 1.8 ± 2.5 vs 1.5 ± 2.0; 2016, 2.0 ± 2.4 vs 1.8 ± 2.5; 2017, 1.7 ± 2.3 vs 1.4 ± 2.1 hours/week). Those who walked <5 minutes on their average daily walk to school were more likely to have obesity (OR: 1.96, 95% CI 1.03-3.73) than those who spent ≥15 minutes on walking to school. When stratified by gender, this higher risk was only observed in girls (OR: 3.01, 95% CI 1.09-8.35). Children who spent more time in screen viewing were more likely to have obesity (OR: 1.13, 95% CI 1.06-1.21) and have central obesity (OR: 1.05, 95% CI 1.02-1.09). The association for obesity was consistent in boys and girls (boys, OR: 1.15, 95% CI 1.05-1.25; girls, OR: 1.12, 95% CI 1.00-1.24).

CONCLUSIONS

More screen time and less walking time were risk factors for developing obesity in urban Chinese children. The associations varied by gender.

Greenness may improve lung health in low-moderate but not high air pollution areas: Seven Northeastern Cities' study

INTRODUCTION

There is growing interest in the impact of greenness exposure on airway diseases, but the impact of greenness on lung function in children is limited. We aimed to investigate the associations between greenness surrounding schools and lung function in children and whether these associations are modified by air pollution exposure.

METHODS

Between 2012 and 2013, a cross-sectional survey and spirometry were performed among 6740 school children. Lung function patterns were determined as obstructive forced expiratory volume 1 s/forced vital capacity (FEV₁/FVC <0.8) or restrictive (FEV₁/FVC ≥0.8 but FVC <80% of predicted). School greenness was defined by Normalized difference vegetation index (NDVI) and soil-adjusted vegetation index. Nitrogen dioxide, sulphur dioxide and particular matter concentrations were assessed using a spatiotemporal model and national monitoring data. Two-level generalised linear models were used to investigate associations and interactions.

RESULTS

Overall, an IQR in NDVI within 500 m was associated with higher FEV₁ (+57 mL 95% CI 44 to 70) and FVC (+58 mL 95% CI 43 to 73). NDVI was similarly associated with 25% reduced odds of spirometric restriction (OR: 0.75, 95% CI 0.65 to 0.86). However, among children exposed to the highest compared with the lowest quartile of particulate matter, increasing NDVI was paradoxically associated with lower -40 mL FVC (95% CI -47 to -33, p interaction <0.05).

DISCUSSION

Our findings suggest that, in this study population, greening urban areas may promote lung health in low-moderate pollution areas but not in high air pollution areas. If the findings are replicated in other moderate-to-high pollution settings, this highlights a need to have a flexible green policy.

Does Dietary Diversity Reduce the Risk of Obesity? Empirical Evidence from Rural School Children in China

Childhood and adolescence overweight and obesity have implications for both health consequences and economic burden. Although it has been an emerging public health problem for primary school children in rural China and the importance of the diet–health link has been stressed for many years, rigorous analysis of the dietary diversity and obesity among children is rare. To clarify this issue, this study provides a better understanding of the functional linkage between dietary diversity and obesity by analyzing data from nearly 8500 rural primary students (aged from 10 to 13 years old) covering three provinces in China. Our estimation results show that there is a significantly negative correlation between dietary diversity and the probability of being overweight among primary students. In particular, for subgroups with higher dietary diversity, the negative correlation between dietary diversity and the incidence of overweight or obesity is stronger, and the absolute value of the coefficient is greater. The results also suggest that the increase in the consumption frequency of all dietary categories can significantly lead to a lower proportion of overweight. Thus, we conclude that higher dietary diversity can help to lower the risk of overweight and obesity among primary school children, presumably through increasing the daily frequency of food intakes and developing a more diverse dietary pattern.

The associations of specific school- and individual-level characteristics with obesity among primary school children in Beijing, China

OBJECTIVE

We aimed to investigate the associations between school-level characteristics and obesity among Chinese primary school children with consideration of individual-level characteristics.

DESIGN

This cross-sectional study was conducted in 2015/2016. School-level characteristics were assessed using an interviewer-administered school questionnaire, and a 'school-based obesity prevention index' was further developed. Individual-level characteristics were collected by self-administered questionnaires. Objectively measured height and weight of students were collected, and obesity status was classified according to the International Obesity Task Force criteria for Asian children. Generalised linear mixed models were used to estimate the associations among the school- and individual-level characteristics and obesity of students.

SETTING

Thirty-seven primary schools from an urban and a rural district of Beijing, China.

PARTICIPANTS

School staffs, 2201 students and their parents.

RESULTS

The school-based obesity prevention index involved the number of health professionals, availability of students' health records, monitoring students' nutrition status, frequency of health education activities, reporting achievements of obesity prevention activities to parents, duration of physical activity during school time and availability of playground equipment. The prevalence of obesity was lower in schools with the higher index value compared with that in schools with the lower index value (OR 0·56; 95 % CI 0·40, 0·79). Some individual-level characteristics were negatively associated with childhood obesity: liking sports, duration of screen time ≤2 h/d, perceived lower eating speed, parental non-overweight/obesity.

CONCLUSIONS

Irrespective of individual-level characteristics, the specific school-level characteristics had a cumulative effect on obesity among Chinese primary school children. Further school-based obesity intervention should consider these characteristics simultaneously.

Impact of neighbourhood food environment on diet and obesity in China: a systematic review

OBJECTIVE

This study systematically reviewed literature on the neighbourhood food environment in relation to diet and obesity among residents in China.

DESIGN

A keyword search of peer-reviewed articles was performed in Cochrane Library, PubMed, and Web of Science. Eligibility criteria include study designs: longitudinal/cohort studies or cross-sectional studies; study participants: people of all ages; exposures: neighbourhood food environment (e.g. restaurants, supermarkets, wet markets, fast-food restaurants, or convenience stores); outcomes: diet and/or body weight status; and country: China.

RESULTS

Seventeen studies met all criteria and were included. Among the eight studies that assessed the neighbourhood food environment in relation to diet, six reported at least one statistically significant relationship in the expected direction, whereas the remaining two exclusively reported null effects. Among the eleven studies that assessed the neighbourhood food environment in relation to body weight or overweight/obesity, ten reported a significant association whereas the remaining one reported a null relationship. Variety, density, and proximity of food outlets were positively associated with local residents' dietary diversity, portion size, and daily caloric intake. Density and proximity of fast-food restaurants and convenience stores were positively associated with local residents' adiposity in some but not all studies. Evidence linking any specific food outlet type to diet/obesity remains lacking due to the small number of studies and heterogeneities in food environment measures, geographical locations, and population subgroups.

CONCLUSIONS

The neighbourhood food environment may influence diet and obesity among Chinese residents but the evidence remains preliminary. Future studies adopting an experimental study design and objective/validated environment and dietary measures are warranted.

NASA Mission X Program for Healthy Eating and Active Living among Taiwanese Elementary School Students

PURPOSE

This study assessed the effects of an intervention program adapted from the NASA Mission X (MX) program on children's Healthy Eating Active Living (HEAL) knowledge and behaviors and anthropometry.

METHODS

This clustered randomized control trial recruited 8 elementary schools in remote rural areas of Northern Taiwan. The intervention was the 8-week MX program. All the 3rd and 4th graders were invited to the study (n = 245). Children's weight, height, HEAL knowledge and behaviors were measured pre- and post-intervention.

RESULTS

The intervention group had significantly more improvements than control group in physical activity knowledge score (+0.91 vs. +0.25, p = 0.002), diet knowledge score (+0.62 vs. +0.17, p = 0.044), and score of interests in NASA and space exploration (+0.34 vs. -0.07, p < 0.0001). BMI increased from 18.4 to 18.6 (p < 0.05) for the control group but did not change for the intervention group. The changes in BMI between groups did not differ significantly.

CONCLUSION AND PRACTICE IMPLICATIONS

This randomized controlled trial showed that the NASA MX program was feasible and acceptable among children in Taiwan, and improved children's HEAL knowledge. (ClinicalTrials.gov registration: NCT03355131).

Association between community characteristics and implementation of community programmes and policies addressing childhood obesity: the Healthy Communities Study

BACKGROUND

Little is known about whether characteristics of communities are associated with differential implementation of community programmes and policies to promote physical activity and healthy eating. This study examines associations between community characteristics (e.g. region and race/ethnicity) and the intensity of community programmes and policies implemented to prevent childhood obesity. It explores whether community characteristics moderate the intensity of community efforts to prevent childhood obesity.

OBJECTIVE

The objective of this study is to investigate associations between community characteristics and the intensity of community policies and programmes to prevent childhood obesity documented in the Healthy Communities Study that engaged a diverse sample of US communities.

METHOD

Programmes and policies were documented in 130 communities across the USA, reporting over 9000 different community programmes and policies to prevent obesity among children ages 4-15. We examined associations between community characteristics and the intensity of community programmes and policies implemented (i.e. their amount and reach, duration and strength of change strategy).

CONCLUSION

Community characteristics explain 25% of the variability in the intensity of community programmes and policies implemented in communities. Particular characteristics - urbanicity, region, being a large county and the per cent of African-Americans in a community - contributed to more (over 18% of the 25%) of the observed variability.

Prevalence and Risk Factors of Asthma and Allergy-Related Diseases among Adolescents (PERFORMANCE) study: rationale and methods

Despite a considerable number of international reports on allergic diseases among children, information about the prevalence and risk factors of asthma and allergy-related diseases among Indian adolescents is relatively sparse. The Prevalence and Risk Factors of Asthma and Allergy-Related Diseases among Adolescents (PERFORMANCE) study has been conceived to study the aetiology of asthma and allergic diseases including rhinoconjunctivitis, atopic eczema and food allergies among adolescents in West Bengal, India, using standardised methods and collaborations. The aims of the study are: 1) to estimate the prevalence and risk factors of asthma and allergic diseases among the adolescents residing in rural, suburban and urban areas of West Bengal; 2) to obtain information about the possible role of lifestyle factors (smoking, diet and physical activity) on the disease prevalence; and 3) to create a network for further investigation on social, environmental and genetic factors affecting the diseases. The PERFORMANCE study comprises two phases. The phase I study will investigate the prevalence and possible contributing factors of asthma and allergic diseases in a defined population. The phase II study will be performed as a follow-up of phase I to assess the incidence of asthma and allergic diseases.

The PERFORMANCE study: investigating the prevalence and risk factors of allergy and asthma among Indian adolescentshttp://ow.ly/jP2v30kmt8u