Objective: Childhood obesity is high on the global public health agenda. Although risk factors are well known, the influence of social risk on the therapeutic outcome of lifestyle intervention is poorly examined. This study aims to investigate the influence of migration background, low education, and parental unemployment. Methods: 62,147 patients participated in multidimensional lifestyle intervention programs in 179 pediatric obesity centers. Data were collected using standardized software for longitudinal multicenter documentation. 12,305 (19.8%) attended care for 6-24 months, undergoing an intensive therapy period and subsequent follow-ups for up to 3 years. A cumulative social risk score was calculated based on different risk indicators. Results: Migration background, low education, and parental employment significantly influenced the outcome of lifestyle intervention. The observed BMI-SDS reduction was significantly higher in the subgroup with low social risks factors (Δ BMI-SDS -0.19) compared to those presenting moderate (Δ BMI-SDS -0.14) and high social risk (Δ BMI-SDS -0.11). Conclusion: Our data underline the effect of children's social setting on the outcome of multidimensional lifestyle intervention. The presence of a high social risk burden is a negative predictor for successful weight loss. Specific therapeutic programs need to be developed for disadvantaged children and adolescents.