Childhood Obesity Intervention Study

A School-based Multicomponent Intervention Study for Preventing Excessive Weight Gain Among Primary School Students

Globally, childhood overweight and obesity is a public health problem. Although the rising trend in children's body mass index (BMI) has plateaued in some high-income countries, it has accelerated in low- and middle-income countries. It is especially true amongst Chinese children with the annual increase rate of obesity during 2010-2014 greater than any other periods from 1985 to 2010. With the dramatic economic development in China, children are now growing up in an increasingly 'obesogenic' environment. For example, the availability and ubiquity of computers and smart phones promote sedentary time, and access to energy dense food and sugar sweetened beverages is now widespread. Effective childhood obesity intervention is urgently needed in China. Although over 20 intervention studies for overweight/obesity among children and adolescents have been conducted in China since the 1990s, most of them had moderate or serious methodological weaknesses. For example, they did not report the number of students, schools or districts initially approached to participate, raising the possibility of selection and recruitment bias. Additionally, although they stated the allocation of intervention and control were randomized, no description of the method of randomization was reported. Given the relative lack of high-quality interventions for childhood overweight/obesity, the investigators designed a cluster randomized controlled trial to assess the effectiveness of a multicomponent one-academic-year intervention among 24 primary schools (approximately 1200 students) in the eastern (Beijing), middle (Shanxi) and western (Xinjiang) part of China. The study aims to identify: 1) whether the school-based intervention will be effective for preventing excessive weight gain among children; 2) whether the intervention will be beneficial for improving healthy eating, physical activity and reducing sedentary behaviors among children.

Schools in the intervention arm will receive a multicomponent intervention at the school-, parent- and student-level, with a mobile application to promote the collaboration between investigators, school teachers, parents and students. The school-level intervention elements will include school policies and health education for teachers. The parent-level intervention elements will include health education for parents and promoting students' physical activity at home. The student-level intervention elements will include health education for students, promoting students' physical activity in school and monthly monitoring of weight and height.

Schools assigned to the control group will have usual education provision throughout their participation in the trial, and after finishing the study they will be offered the health education package, policy suggestion and materials as the schools in the multicomponent intervention group.

School-level policies Students will not be allowed to drink sugar-sweetened beverage or eat unhealthy snacks in schools and drinking water will be advocated. Monitoring of students' weight and height Students will be monitored their weight and height monthly. Promotion of physical activity Students will be required to perform at least 60 minutes of moderate to vigorous physical activity each day in school and increase their physical activity outside school (reaching 30 minutes per weekday and one hour per weekend day). Health education activities Health education activities will be provided for students (10 sessions, 40 minutes per session, 2-3 weeks once), parents and school teachers. The mobile application The mobile application will disseminate health education knowledge among students, parents and teachers, monitor and provide feedback of students' BMI status and diet and physical activity behaviors.

the difference between arms in the change of students' BMI immediately after the intervention completion

the difference between arms in the change of students' BMI one year after the intervention completion

We will use a self-designed questionnaire including 8 items to assess the change of students' knowledge related to energy balance. For example, we will ask students, "Is it right that drinking sugar-sweetened beverage cannot substitute drinking water." Three choices will be provided (Right; Wrong; Not clear).

Questions were designed based on a validated 7-day physical activity questionnaire. Kappa values for a two-week test-retest ranged from 0.46 to 0.79.

We will use a parent-rated "Children Eating Behavior Questionnaire" (CEBQ) to assess students' eating behaviors, including responsiveness to food, enjoyment of food etc. This 35-item instrument has been shown relatively good reliability.

We will use a self-designed questionnaire to ask the average duration of doing homework, watching television and playing electronic devices per day during the last week, respectively.

We will use a self-designed questionnaire to measure school obesity-related policies involving school administration, health education, management of overweight or obesity, communication with the families of students and school lunch.

We will use two items to assess it. First, we will ask "Have you taken action to reduce your weight during the last three months?" Yes/no choices will be provided. And then, we will ask "Do you intend to reduce your weight currently?" This item will be provided 5 choices from "completely not intend" to "intend very much".

1. Eligibility criteria for schools The trial recruited a total of 24 schools. A convenience sample of 8 schools were selected from Beijing, Shanxi (Changzhi City) and Xinjiang (Urumqi City) respectively. Inclusion Criteria for schools: school leader agreeing to implement this intervention; requiring school teachers who can implement this intervention (e.g. school doctors, physical education teachers, physical education teachers, etc.); having at least 50 children from Grade 4 (at the start of the intervention) per school;having a even number of schools within each district. Exclusion Criteria for schools: boarding schools;schools solely for children with special skills; schools of minor ethnic groups; similar programme (focus on weight gain prevention) would be conducted in schools during the study period; schools having a cancelling or relocation plan during the study period. 2. Eligibility criteria for classes One class per school will be selected if the estimated number of students enrolled in the programme is no less than 40 within the selected class; two classes per school will be selected if the estimated number of students enrolled in the programme is less than 40 within the selected class. 3. Eligibility criteria for students Eligible children will be those whose primary caregivers will provide written consent to participate the study. After collecting students' medical history from their parents, we will exclude individuals suffering from or having a history of any cardiovascular and metabolic diseases, asthma and disabilities that limit their ability to perform physical activity.

Liu Z, Gao P, Gao AY, Lin Y, Feng XX, Zhang F, Xu LQ, Niu WY, Fang H, Zhou S, Li WH, Yuan JH, Xu CX, Wu N, Li HJ, Wen LM, Patton GC, Wang HJ, Wu YF. Effectiveness of a Multifaceted Intervention for Prevention of Obesity in Primary School Children in China: A Cluster Randomized Clinical Trial. JAMA Pediatr. 2022 Jan 1;176(1):e214375. doi: 10.1001/jamapediatrics.2021.4375. Epub 2022 Jan 4.

Liu Z, Wu Y, Niu WY, Feng X, Lin Y, Gao A, Zhang F, Fang H, Gao P, Li HJ, Wang H; study team for the DECIDE-children study. A school-based, multi-faceted health promotion programme to prevent obesity among children: protocol of a cluster-randomised controlled trial (the DECIDE-Children study). BMJ Open. 2019 Nov 2;9(11):e027902. doi: 10.1136/bmjopen-2018-027902.