The present study aimed to enrich the scientific evidence on obesity prevention programmes for adolescents from socio-economically disadvantaged backgrounds with practice-based experiences from both scientific and professional experts in the field of youth obesity prevention. We used the participatory method of concept mapping. Two concept mapping sessions were conducted: one with programme coordinators of national/regional obesity prevention programmes across Europe (n = 8) and one with scientists participating in European obesity prevention projects (n = 5). Five recommendations were extracted from both concept maps: (1) involve adolescents in the design and delivery of the programme, (2) invest in family/parental capacity building, (3) provide and support a healthy school food and physical activity environment, (4) regulate exposure to unhealthy messages/advertising and (5) facilitate safe and active travel. These recommendations can be used as a conceptual framework for programme development for preventing obesity in adolescents.