Background: To address the challenge of juvenile obesity, effective therapeutic concepts focusing on lifestyle changes are necessary. A relevant aspect is the media use, which is associated with nutrition and physical activity patterns and is influenced by socio-demographic factors. To optimise obesity therapy, the use of media depending on these socio-demographic factors needs to be analysed to adjust the aims, content and methods of interventions as well as to harness the potential of media use in obesity therapy. The question considered in this research is: What media and physical activity patterns show 11- to 17-year-old obesity therapy participants in dependence on socio-demographic factors? Methods: A national multicentre study was conducted in 2015. A questionnaire was used to survey 432 participants' aged 13.75 ± 1.4 years. Standardised instruments were used to assess the variables: physical activity, media use and socio-demographic factors. Results: The participants were 1-hour physically active for 3.9 ± 1.9 days/week, 14.1% daily. Televisions, mobile phones and computers were available in all socio-demographic groups and used for 2 h/day. Socio-demographic differences emerged in the duration of media use (h/day). Girls were found to use mobile phones for longer (2.49 vs. 1.90; p < 0.01) and spend less time on game consoles than boys (0.55 vs. 1.65; p < 0.01). Conclusion: Compared to current recommendations, the sample shows reduced physical activity and increased media use, which vary between the groups. Hence, differentiated therapy approaches appear recommendable. Future research needs to evaluate, how media (despite its risks) can facilitate therapy, training and aftercare concepts.