Keywords: Adolescents (13-19 years), Behaviour Modification (e.g., provision of item/tool, incentives, goal setting), Community, Education / Awareness & Skill Development / Training, Health Care Setting, Home, Hospital, Meta-analysis, Nutrition, Obesity, Physical Activity, Primary health care provider office (e.g., Public health nurse, dietitian, social worker), School, Social Support (e.g., counseling, case management, outreach programs) , Youth Health