sample and setting : this study was conducted at pubic school in a northern province of thailand. Two schools were randomly selected from 16 schools : the experimental group, school A , and the control group , school B. randomization was accomplished via drawn lots without replacement from the school identification number . The first researcher obtained permission from the Faculty of nursing, Chiang Mai University to conduct the study before requesting the prospective schools to participate. Onc permission had been granted, participants of each school were drawn independently from the total number of overweight students in fifth grade to become the experiental group receiving an individual-based intervention, and the control group receiving the school's usual healthy-eating educational program only.