SummaryThe objective of this systematic review is to provide a qualitative comparison of interactive electronic media interventions for the prevention or treatment of obesity and/or obesity-related behaviours in children and adolescents. Literature searches of 12 databases from the earliest publication date until March 2010 were conducted. Twenty-four studies in which children and/or adolescents interacted with electronic interventions delivered as adjunct or sole interventions for the prevention or treatment of obesity and/or obesity-related behaviours met the inclusion criteria. Fifteen focussed on obesity prevention and nine on treatment interventions. The average study quality design score was 45%. Most studies demonstrated some form of significant outcome (e.g. reported changes in dietary and/or physical activity behaviours) in participants receiving interactive electronic interventions, with 11 out of 15 studies leading to positive changes in measured or reported adiposity outcomes. In 87% of studies, the effects of interactive electronic interventions were not separately evaluated from other intervention components. These results should be viewed with caution because of the overall poor quality of the studies. Studies were mostly conducted in the USA, largely in minority populations, and the direct transferability of interventions to other populations is unclear. Further high quality research is needed in this area to accurately inform the evidence base.

Objective: The aim of the present study was to describe the nature and extent of food marketing on popular children's websites and food product websites in Australia. Methods: Food product websites (n 119) and popular children's websites (n 196) were selected based on website traffic data and previous research on frequently marketed food brands. Coding instruments were developed to capture food marketing techniques. All references to food on popular children's websites were also classified as either branded or non-branded and according to food categories. Results: Websites contained a range of marketing features. On food product websites these marketing features included branded education (79?0 % of websites), competitions (33?6 %), promotional characters (35?3 %), downloadable items (35?3 %), branded games (28?6 %) and designated children's sections (21?8 %). Food references on popular children's websites were strongly skewed towards unhealthy foods (60?8 % v. 39?2 % healthy food references; P , 0?001), with three times more branded food references for unhealthy foods. Branded food references displayed similar marketing features to those identified on food product websites. Conclusions: Internet food marketing uses a range of techniques to ensure that children are immersed in brand-related information and activities for extended periods, thereby increasing brand familiarity and exposure. The relatively unregulated marketing environment and increasing use of the Internet by children point to the potential increase in food marketing via this medium. Further research is required to investigate the impact of Internet food marketing on children's food preferences and consumption, and regulatory options to protect children.

Although adolescent engagement was modest, SMS and e-mail communication is a feasible and acceptable adjunct to group lifestyle intervention and telephone coaching in overweight and obese adolescents. Healthy eating messages and those concluding with "please reply" elicited the highest reply rates, and thus these message types should be included in future adolescent e-contact interventions.