Identification of determinants for weight reduction in overweight and obese children and adolescents

We conducted a pilot trial of electronic technology integrated into the treatment of children and adolescents who are overweight or obese. A total of 30 patients (mean age 14 years, mean BMI 32.7 kg/m(2)) were admitted to our hospital to participate in a structured treatment and teaching programme (SUP). To assess physical activity and eating habits, a mobile motion sensor board (MoSeBo) or a sensor for physical activity, integrated into a mobile phone with digital camera (Dia Trace) was used. Over an average period of four days of monitoring, the mean intensity (15.4 activity units) and duration of physical activity (267 min/d) were recorded with the mobile sensors. The mean time spent walking was 64 min/d, running 11 min/d, cycling 24 min/d and car driving 21 min/d. There were significant differences (P< 0.001) between self-reported physical activity and objective assessment: in general the duration of physical activity documented by children and adolescents was much higher than the objective assessment. Similarly, the real caloric intake was higher than the self-estimates (P = 0.085). A multivariate analysis showed that the following variables were significantly associated with weight reduction in the hospital SUP (R-squared = 0.59): high motivation, intrafamilial conflicts, duration of physical activity assessed with the MoSeBo/DiaTrace system, and the body fat mass at onset of therapy. All children and adolescents included in the trial completed it. Although the MoSeBo/DiaTrace system was used for a relatively short period in each patient, the high acceptance demonstrated that it could be integrated into therapy easily.