Background Next to the school environment, the family and community environment are key for young people's behaviour and for promoting physical activity (PA).

Methods A review of reviews was conducted, after which a literature search was conducted (in PubMed, Scopus and PsychInfo) from August 2007 (search date of the most recent review) to October 2010. Inclusion criteria were study population aged 18 years or younger, controlled trial, no PA control condition, PA promotion intervention and reported analyses of a PA-related outcome. Methodological quality was assessed, and data on intervention details, methods and effects on primary and secondary outcomes (PA, body composition and fitness) were extracted.

Results Three previous reviews were reviewed, including 13 family-based and three community-based interventions. Study inclusion differed for each review, but all concluded that the evidence was limited, although the potential of family-based interventions delivered in the home and including self-monitoring was highlighted. A further six family-based and four community-based interventions were included in the updated review, with a methodological quality score ranging from 2 to 10 and five studies scoring 6 or higher. Significant positive effects on PA were observed for one community-based and three family-based studies. No distinctive characteristics of the effective interventions compared with those that were ineffective were identified.

Conclusions The effect of family- and community-based interventions remains uncertain despite improvements in study quality. Of the little evidence of effectiveness, most comes from those targeted at families and set in the home. Further detailed research is needed to identify key approaches for increasing young people's PA levels in family and community settings.