Background This review synthesises evidence regarding associations between young people's social networks and their eating behaviours/bodyweight, and also explores how these vary according to the setting and sample characteristics. Methods A systematic review of cross-sectional and longitudinal observational studies examining the association between measures of young people's social networks based on sociometric data and eating behaviours (including calorific intake) and/or bodyweight. Results There is consistent evidence that school friends are significantly similar in terms of their body mass index, and friends with the highest body mass index appear to be most similar. Overweight youth are also less likely to be popular and more likely to be socially isolated at school. Frequency of fast food consumption has also been found to cluster within groups of boys, as have body image concerns, dieting and eating disorders among girls. Conclusion School friendships may be critical in shaping young people's eating behaviours and bodyweight and/or vice versa, and suggests the potential of social-networkbased health promotion interventions in schools. Further longitudinal research is needed to examine the processes via which this clustering occurs, how it varies according to school context, and the effects of non-school networks. BACKGROUND

Objectives: To empirically test the impact of dietary intake at several time points in childhood on children's school attainment and to investigate whether any differences in school attainment between children who ate packed lunches or school meals was due to who these children were, their pre-school dietary patterns, or to what they ate at school. Design: Using longitudinal data available in the Avon Longitudinal Study of Parents and Children (ALSPAC), multivariate linear regression was used to assess the relative importance of diet at different ages for school attainment. Main outcome measures: Three indicators of school attainment were used: at ages 4-5 entry assessments to school, at ages 6-7 Key Stage 1 national tests and at ages 10-11 Key Stage 2 national tests. These outcome variables were measured in levels as well as in changes from the previous educational stage. Results: The key finding at age 3 was that ''junk food'' dietary pattern had a negative association with the level of school attainment. A weak association remained after controlling for the impact of other dietary patterns at age 3, dietary patterns at ages 4 and 7 and other confounding factors. The authors did not find evidence that eating packed lunches or eating school meals affected children's attainment, once the impact of junk food dietary pattern at age 3 was accounted for in the model. Conclusions: Early eating patterns have implications for attainment that appear to persist over time, regardless of subsequent changes in diet.The content and quality of food eaten is related to developmental, cognitive and behavioural outcomes that are important in childhood for health and well-being, but also for specific experiences, such as school life.

The lack of consistent differences in risk between migrants and non-migrants highlights the importance of the local context in mediating risk among migrant FSWs. The higher prevalence of HIV among some FSWs originating from African countries is likely to be due to infection at home where HIV prevalence is high. There is a need for ongoing monitoring and research to understand the nature of risk among migrants, how it differs from that of local FSWs and changes over time to inform the delivery of services.