The 'Meir children's sport and health center' runs a multi-disciplinary intervention program for the treatment of overweight and obese children and adolescents. The program includes physical activity, dietary guidelines, medical supervision and behavioral treatment. The participants are routinely weighed once a week, at the same day and time, in order to supervise their progress. According to our experience, the child can predict his weight change, based on his "behavior" in the previous week. To our knowledge the overweight/obese child's ability to predict his weekly weight change, while participating in a multi-disciplinary intervention program, has never been tested.