Eighteen months after completion of long-term treatment of 98 extremely overweight juveniles in the rehabilitation center Insula, this study revealed an improvement in the age-specific body mass index (BMI-SDS) in 55.1% of the cases, when all the non-responders (approx. 22%) were evaluated as failures. An improvement of at least 0.2 or 0.5 BMI SDS points was achieved in 41.8% and 21.4%, respectively.