Study design and population
An interventional study was designed in the primary schools for girls and boys located in the 17th district of Tehran for 6 months from April 2019 to November 2019. A multistage sampling process was used to select schools. Among girls’ schools, 2 schools were selected as the intervention group (first and third choice) and 2 schools (second and fourth choices) as the control group. Also, among boys’ schools, 2 schools were selected as the intervention group (first and third choices) and 2 schools (second and fourth choices) as the control group. Then, in each school, eligible students were determined in clusters at a grade level and everyone within the chosen clusters entered the control or intervention group using the sealed opaque envelopes. One hundred and eighty children aged 6–12 years with overweight and obesity were allocated to two groups of intervention (n = 90) and control (n = 90). The sample size (n) with 5% error rate and 80% statistical power was assessed using the following equation (Eq. 1) [14, 15]:
$$ n=\frac{{\left({Z}_1-\frac{\alpha }{2}\right)}^2\left({\sigma}_1^2+{\sigma}_2^2\right)}{{\left({\mu}_2-{\mu}_1\right)}^2} $$
(1)
Only the statistical consultant in this study was blinded.
Inclusion and exclusion criteria
Students with obesity and overweight assessed by the Centers for Disease Control and Prevention (CDC) growth charts were qualified for participation in this project. Based on the Body Mass Index (BMI) reported by the CDC growth charts, overweight (85th percentile ≤ BMI < 95th percentile), and obese (95th percentile ≤ BMI) children in this research were considered according to the ender and age range [16]. However, children with underweight and normal weight at the same age range, having the underlying illness, the lack of access to the Internet and the lack of willingness to cooperate were excluded.
Intervention program: design and implementation
The analysis, design, development, implementation, and evaluation (ADDIE) development model study was used to assess the best tool to educate schoolchildren about healthy eating and physical activity to reduce their obesity and overweight. The ADDIE, as 5 a systematic instructional design model, empowers training professionals and designers to develop more principled and effective training through a dynamic and flexible guideline. This approach is based on all theories of cognition, behaviorism, and constructivism. This model covers the design of learning topics and perspectives and different environments and is therefore called a generic paradigm [17]. This model applies to any learning, both traditional and electronic. The ADDIE model’s phases include (i) analysis, (ii) design, (iii) development, (iv) implementation, and (v) evaluation. Five steps must be taken for the design of the training so that each step is considered as an input for its next step [18]. Accordingly, the different steps were implemented in the present study as follows:
Phase I: analysis
An extensive literature review was initially performed to find a variety of educational models. It was decided to make the final decision after interviewing with experts and summarizing the opinions. Before the meeting, the purposes and the different issues were discussed concerning the selection of the weight loss methods and related articles. Some information was also collected on overweight and obese students, their educational needs, purposes, and practices, and study limitations.
Phase II: design
The model design was completed in a separate meeting with the relevant experts. According to the age group of children with overweight and obesity, education to their parents was approved using the website as an efficient, modern, and accessible method. The meeting also addressed the educational needs of students that had been previously collected. Fifteen expert panel members 6 including intervention researchers, healthcare professionals, and school practitioners selected the most relevant lifestyle modification interventions to reduce obesity and overweight risk factors. After giving the preliminary explanations and discussing the types of interventions at the meeting, two healthy lifestyle views were finally endorsed to be used on the educational site. These interventional patterns included (i) 5–2–1-0 healthy habit (HH), and (ii) healthy eating plate (HEP). The HH pattern is based on the daily consumption of five units or more fruits and vegetables, 2 h or less of everyday use of television or other electronic equipment, 1 h or more daily physical activity, and no sugary drinks [19]. The HEP is a guide to choosing a healthy and balanced diet. The main message of the HEP is to focus on the quality of the consumed food, which summarizes: (i) always try to make half of your plate full of fruits and vegetables, (ii) fill a quarter of the plate with whole grains, (iii) fill a quarter of the plate with protein sources, (iv) consume a balanced amount of vegetable oils, (v) drink water, tea or coffee, and (vi) do not forget about exercise [20]. It was decided to upload educational material on the “Peak-e-Salamat” website entitled “healthy living pattern for children aged 6-12 years old”. The “Peak-e-Salamat” is a website representing a categorized collection of web pages, images, multimedia files, or other digital tools related to the general and particular health issues that reside on one or more hosts known as web servers. “Peak e-Salamat” is also considered as an educational aid content generation system about understanding illnesses and self-care and provided information to the general population, patients, and medical professionals.
Phase III: development
Each of the two health patterns (5–2–1-0 HH and HEP) included training frameworks. In the form of instructional information, they were written in a simple language to put the content on the training website during the implementation phase.
Phase IV: implementation
After holding numerous meetings with educational institutions for justifying the research project, the necessary permits to start its implementation were obtained. The research team selected eligible children with overweight or obesity at elementary schools, during 30 days before the start of the study. After stating the mission of the study, and receiving a written informed consent from the parents, children who also had verbal agreement were included in the study. The importance of weight loss and its risks was emphasized in the first virtual session for the interventional group. Then the 5–2–1-0 HH and HEP patterns in reducing the weight accompanied by encouraging ways to the participation of students were educated. At the end of the sessions, some questions were designed to raise parental attention to continue the training. Educational materials were uploaded to the website twice a week. Parents were surveyed by forming a virtual group for questions and answers as well as sending personal text messages following the uploading of educational materials. Phone calls were also made once a month to answer their questions or concerns about the site or plan. Parental assessment method during the study approved by 15 experts. At the end of the 3rd month, the height and weight of the children were measured only in the intervention group. This process was repeated at the end of the 6th month in both groups. The expected outcome of this study was a further reduction in BMI and weight for age percentile and a comparative study at the beginning and end of the study. Participants were not exposed to greater or additional risks due to the lifestyle training intervention. There was no specific intervention for the control group but it included all the preventive recommendations and training that were part of the schools’ routine.
Phase V: evaluation
At this stage, the height and weight status data as well as children’s demographic data were entered into SPSS software package version 25.0 (SPSS Inc., Chicago, IL, USA) to analyze statistically, and then the report of results was written.
Data collection
The demographic data, including student’s age and gender, parents’ age, student’s weight and height, family size, and parent’s educational level and occupational status, were collected through a self-designed questionnaire. The validity of the demographic questionnaire was confirmed by 15 experts. The height was determined without shoes in a standing position by a stadiometer to the nearest 0.5 cm, whereas the shoulders were in a normal state. The bodyweight of subjects wearing light clothes and no shoes or socks was measured and recorded using a standard, calibrated electronic scale (Xiaomi, China) with an accuracy of 100 g. The BMI as the primary outcome was determined by calculating the weight (in Kg) divided by the square of assessed height (in m2). Children Growth Chart Calculator of Center for Disease Control and Prevention (CDC) used to calculate the weight for age percentile as a secondary outcome which complements the results of the body mass index. The weight, height, BMI, and weight for age percentile were assessed before and after the six-month educational intervention.
Data analysis
The data of categorical variables were expressed as frequency and percentage, whereas the results of numerical variables were represented as mean ± standard deviation. Inferential statistics in terms of independent and paired t-tests, Chi-squared (χ2) test/Fisher’s exact test, repeated-measures ANOVA, was carried out to compare the significant difference between means of different groups. The AVCOVA test used to analyze the difference of 6 months BMI/weight for age percentile, with beginning BMI/weight for age percentile as covariates. The SPSS software was used to analyze the data at a significant level of p < 0.05.