OBJECTIVE: To assess the long-term effects of a multidisciplinary approach involving structured fun-type skill learning physical activities in the treatment of obese and overweight children. DESIGN: A longitudinal investigation incorporating repeated measurements before and after the 8 week intervention and after the 44 week follow-up period. METHODS: The camp programme (Massachusetts, USA) utilised structured fun-based skill learning physical activities, moderate dietary restriction and behaviour modification. The primary aims of the intervention were to reduce body mass and promote the maintenance of the reduction in body mass using an alternative to standard exercise prescription. SUBJECTS: One-hundred and ninety-four children (64 boys and 130 girls, aged 12.6±2.5 y) enrolled at a summer weight loss camp, of which 102 children (38 boys and 64 girls aged 13.6±2.4 y) returned 1 y later. MEASUREMENTS: On commencement of the programme all children were assessed for body mass and stature. At follow-up, data was available on 102 subjects for body mass and stature. RESULTS: Over the 8 week intervention significant reductions (P=0.00) in body mass were obtained. During the 44 week follow-up significant increases (P=0.00) were noted in body mass, body mass index (BMI) and stature, but as expected there were large variations in the responses. One year after the initial measures had been taken mean body mass and BMI were lower than at the start of the intervention, BMI significantly so (week 0, 32.9 ± 7.4 kg/m²; week 8 29.1 ± 6.5 kg/m²; week 52, 30.05 ± 7.04 kg/m²); (P=0.00). Stature increased significantly (week 0, 1.58 ± 0.12 m; week 52, 1.64±0.11 m) (P=0.00) during this period, demonstrating a reduction in mean body mass over a I y period whilst subjects continued to increase in stature. When changes in BMI are analysed with the use of standard scores, there is a non-significant increase (P=0.07) in BMI... [ABSTRACT FROM AUTHOR]