Procedure: One month prior to the beginning of data collection, the PI reviewed the health records of all preschoolers within each study site school, For the purpose of classifying the overweight children. Then random selection was performed to obtain the eligible sample. Following random selection, the Pl and a research assistant measured the children‘s heights and body weights, once, in a private setting at each school, to determine the children’s weight status. Preschoolers were weighed wearing school uniforms with empty pockets and withoutishoes, while their standing heights were measured without shoes. Each preschooler’s weight and height was measured, via use of the standard recommended technique (beam balance scale and stadiometer),3° to the nearest 0.1 kg and 0.1 cm, respectively. Weight status was classified via use of a Ministry of Public Health growth reference for 2 to 7 years old Thais.‘ The PI then classified the children into specific groups as either case or control subjects. One hundred and twenty overweight preschoolers (case) and 600 nomtal weight preschoolers (control) were identified among the schools. The selected preschoolers were given a consent fonrt and letter, to take to their primary caregivers. The letter described the study and all related ethical considerations. Primary caregivers interested in taking part in the study were asked to have their