In this study we first try to answer the question, whether it is possible to make a successful treatment for obese children in an interdisciplinary program. Second it is asked whether a transfer of this program to further regions in Germany leads to comparable results. In FITOC children from the age of 8-11 years and over the 97. BMI-percentile are integrated in this program. The goals weight management, increased physical fitness and improvement of the cardiac risk profile are checked by weight, height, fasting blood serum, a standardized cycle ergometry and a medical measurement at the beginning, after treatment and at all check-ups. The recorded medical data show clearly that the intervention leads to a significant improvement in almost all checked parts. The successful treatment can be recorded after 8 months, likewise after 2.5 years as a long-term result. The further cornerstones of FITOC nutrition and psychology are not subject of this publication. In future the psychological part in FITOC will be evaluated by standardized inventories. The group from Düren has a success in therapy according to the definition of the program. Thereby it is shown that FITOC is extendable, if teams are trained intensively and the conditions are comparable. FITOC is able to treat obese children successfully over a long period of time. In consideration of the rising prevalence of obesity in childhood and the limited financial resources in health care this outpatient interdisciplinary program is an effective choice of treatment.