Impact of social norms and social support on diet, physical activity and sedentary behaviour of adolescents: a scoping review.

The prevalence of non-communicable diseases (NCDs) in adulthood is rapidly increasing, and it is essential that risk factors for NCDs be addressed in adolescence, both for the health of individuals during adolescence and for their health in later life. These risk factors include diet, physical activity and sedentary behaviour. No literature has been published that comprehensively summarizes the impact of social norms and social support on these behaviours among adolescents. Therefore, a scoping review was conducted to determine the extent of recent (since 2000) literature available on this topic. A comprehensive search strategy was used to search PubMed and EMBASE for eligible reviews. Review papers (narrative reviews, systematic and non-systematic reviews) published in English in peer-reviewed journals from 2000 to February 2013 were included in the overview. Two of the authors screened the titles and abstracts of the search results independently. Thirty reviews were included in the scoping review. This scoping review has shown sufficient evidence for parental influences, and especially the positive impact of an authoritative parenting style, on healthy behaviours of adolescents, although the evidence is somewhat more compelling for diet than for physical activity and sedentary behaviour. More research is needed to investigate parental and family influences on physical activity and sedentary behaviour. And the effect of peer influences on diet, physical activity and sedentary behaviour of adolescents requires further investigation. The evidence presented affirms the consideration of social norms and social support in the development of interventions to address these behaviours in adolescents. The evidence regarding parenting style provides some concrete guidance for such interventions.