©Freund Publishing House Ltd. Int J Adolesc Med Health 2007;19(3):235-243. Adolescent obesity: Making a difference to the epidemic Elizabeth Denney-Wilson BN, MPH, PhD and Louise A Baur MBBS (Hons), BSc(Med), PhD, FRACP Discipline of Paediatrics and Child Health, University of Sydney, Sydney NSW 2006 Australia Abstract: Adolescent obesity is a major public health problem in Australia, and in many other parts of the world. Recent data suggests that as many as one quarter of young people in Australia are either overweight or obese, and that the majority of obese young people have one or more risk factors for chronic disease. Efforts to reduce the health and economic burden of obesity must focus on both management of affected individuals and prevention of further cases. This paper reviews some of the research currently underway in Australia, and includes recent data on both the prevalence of obesity and associated complications from large surveys and smaller cohorts. State and Federal governments have developed policies aimed at obesity prevention, but these are yet to be fully evaluated. Two large-scale community-based interventions are underway, one of which has reported positive preliminary findings. A number of smaller research programs are examining macro and individual level causation of obesity and include unique research examining the way adolescents perceive their environment. Other research includes the development and evaluation of service delivery models specifically targeting adolescents. A greater emphasis on environmental determinants and management of adolescent obesity is needed in future programs. Key words: adolescent, obesity, aetiology, prevention, treatment, Australia Correspondence: Professor Louise A Baur, Clinical School, The Children’s Hospital at Westmead, Locked Bag 4001, Westmead NSW 2145, Australia. Tel: 612-98453393; Fax: 612-98453389; E-mail: Louiseb3@chw.edu.au Submitted: February 05, 2007.Revised: March 23, 2007. Accepted: March 24, 2007. INTRODUCTION Despite a reputation as an active, sport- loving nation, Australians, including adolescents, have not escaped the obesity epidemic sweeping the world. Currently, more than 25% of adolescent boys and almost 20% of adolescent girls are either overweight or obese (1), with the prevalence of overweight having doubled, and that of obesity trebled, over the past twenty years (2,3). This paper summarises the current situation in Australia, in terms of epidemiology, causes, morbidity, clinical management and recent policy and research developments that include provision of funds for large scale community-based interventions. A number of challenges are evident: firstly, to develop strategies for prevention to reverse the current trends in obesity; and secondly, to provide clinical management appropriate for obese adol- escents. MEASUREMENT OF OVERWEIGHT Body mass index (BMI; weight/height 2 ) is a simple, cost-effective measure of body fat- ness for children, adolescents and adults (4). Among adults, a person with a BMI of