Randomised controlled trials (RCTs) and non-RCTs in a primary care setting or that involved a primary healthcare professional using interventions aimed at treating infants, children or adolescents who were overweight or obese were eligible for inclusion. Trials in which most participants were over 18 years old were excluded. Any outcome that assessed the effectiveness of the intervention on the child was allowed. Trials of primary prevention only were excluded. Participants who had undergone surgery, were obese due to pharmacological therapy or had a congenital disorder were excluded.
The included studies considered overweight and obese participants, obese participants and overweight/at risk of obesity participants. Types of intervention included intensive dietary and/or physical exercise counselling, parental involvement, after-school intervention, telephone/email/mail interventions, health education and family-based interventions alone or in combination. Participant age ranged from three to 17 years. The median proportion of males was 49.5%. Trials were conducted in USA, Israel, Germany, Italy, Australia, and Finland. Reported outcomes varied widely, but could be categorised into four groups: metabolic, behavioural, psychosocial and anthropometric/body composition.
Study selection was undertaken in stages. Two reviewers performed an initial trial selection followed by selection with refined criteria and a full-text stage; one reviewer reviewed remaining titles and abstracts.