The intervention protocol was developed by an expert group from the National Children Obesity Intervention Team, comprising pediatricians, children healthcare doctors, preschool teachers, and nutritionists, and included three integrated components:
Component 1 - training of kindergarten staff: Before the start of the program, two members of the intervention team (a dietitian and a physician) delivered eight 40-min sessions (twice a week for a month) on dietary management in children and daily food purchasing for school doctors and kitchen staff. During the trial, two health education doctors gave lectures every two months on general knowledge in nutrition to all preschool staff, focusing on the promotion of healthy food and restriction of unhealthy food. To assess the effectiveness of these lectures, we administered a questionnaire on the material covered. We also trained the kitchen staff to use the dietary software to plan menu with balanced nutrition for preschool children.
Component 2 - a curriculum promoting healthy diet and lifestyle: We designed a health education curriculum and associated picture books for the children. Children in the intervention group received a 20-minute health education lesson every week, where they had learning activities and games covering healthy food choice, appropriate portion sizes and eating pace, and reduction of sedentary behaviours. Learning aids such as colourful picture books or cards, food models, nursery rhymes and stories were used. Two elements were introduce to increase children's activity such as lunchtime activity and daily dance at less than 10 minutes during break.
Component 3 - collaboration between families and kindergartens: We organized lectures designed for parents every two months during the intervention period. Topics covered included the cause and harms of childhood obesity, advice on healthy diet (increasing consumption of vegetables and fruits, reducing consumption of meat, snacks, fast foods, and eating out, and avoiding sugary drinks), body mass index (BMI) reference for preschool-age children, and how to use growth curves. We produced a handbook for communication between families and schools, to be handed out to every family weekly, in which children's health behaviours were documented and reviewed by teachers and parents. Finally, parents were notified of their children's anthropometric measurements every three months, so that they could plot and interpret their children's growth curves.
