Role of social support on physical activity in adolescent girls

Background: Adolescent girls are insufficiently active to achieve health benefits. As a result they have been targeted as a priority group for increasing physical activity levels. However, physical activity interventions for this population have had limited effect. A better understanding of the correlates of physical activity in adolescent girls may better inform intervention design. Social support describes interactions, resources, and assistance from others to influence physical activity behaviour. Social support has been linked to physical activity in adolescent girls and could be a modifiable correlate of physical activity. This thesis aimed to identify: (1) if there is a positive association between social support and physical activity in adolescent girls, and if so, (2) explore the potential pathways through which social support influences behaviour. Method: Firstly, a systematic review and meta-analysis was conducted to explore the role of different providers (e.g. parents/friends) and types of social support (e.g. emotional/instrumental) on adolescent girls’ physical activity, providing effect size estimations for different combinations of associations. Secondly, an analysis of an 8- week school based physical activity intervention for adolescent girls was conducted. This involved a mediation analysis to examine: (1) if self-efficacy mediated associations between social support and physical activity at baseline; and (2) if social support or self-efficacy mediated the effectiveness of the intervention. Finally, a qualitative study using constructivist grounded theory was conducted to investigate the mechanisms through which social support influences physical activity behaviour through conducting individual interviews with adolescent girls (n = 18). Results: The systematic review and meta-analysis identified small but significant positive associations between social support and physical activity in adolescent girls. Similar magnitudes were identified for parent and friend support effect sizes. The mediation analysis found that self-efficacy mediated the relationship between social support and physical activity, however, social support did not mediate the effectiveness of a physical activity intervention for adolescent girls. The results of the grounded theory study suggest that social support can influence adolescent girls’ physical activity through enjoyment, self-efficacy, overcoming barriers to physical activity, motivation, and performance improvements, as well as enabling physical activity. Conclusions: Whilst only small significant associations between social support and physical activity in adolescent girls were identified, social support may also indirectly influence physical activity through enjoyment, self-efficacy, overcoming barriers, motivation, performance improvements and enabling physical activity. There may be promise in targeting these constructs through social support behaviour change strategies in physical activity interventions for adolescent girls

Credibility of subgroup analyses by socioeconomic status in public health intervention evaluations:An underappreciated problem?

There is increasing interest amongst researchers and policy makers in identifying the effect of public health interventions on health inequalities by socioeconomic status (SES). This issue is typically addressed in evaluation studies through subgroup analyses, where researchers test whether the effect of an intervention differs according to the socioeconomic status of participants. The credibility of such analyses is therefore crucial when making judgements about how an intervention is likely to affect health inequalities, although this issue appears to be rarely considered within public health. The aim of this study was therefore to assess the credibility of subgroup analyses in published evaluations of public health interventions. An established set of 10 credibility criteria for subgroup analyses was applied to a purposively sampled set of 21 evaluation studies, the majority of which focussed on healthy eating interventions, which reported differential intervention effects by SES. While the majority of these studies were found to be otherwise of relatively high quality methodologically, only 8 of the 21 studies met at least 6 of the 10 credibility criteria for subgroup analysis. These findings suggest that the credibility of subgroup analyses conducted within evaluations of public health interventions’ impact on health inequalities may be an underappreciated problem. Keywords: Health inequalities, Health inequities, Equity and public health interventions, Policy impact by socioeconomic statu

A longitudinal and comparative content analysis of Instagram fitness posts

Body dissatisfaction is among the most common mental health challenges experienced by women and has been identified as a risk factor for disordered eating. Research has found that exposure to social media images depicting thin, muscular bodies, often dubbed ‘fitspiration’, may contribute to body dissatisfaction. Image-centred social media platforms, such as Instagram, have rising popularity among adolescents and young adults. However, little is known about the content of images produced by different fitness-related sources, such as those from fitness brands compared with individual users, and how fitness content on social media is evolving over time. This study sought to determine whether Instagram content varied between female fitness influencers and brands and how this content changed between 2019 and 2021. A longitudinal content analysis was conducted on a sample of 400 Instagram images using a coding scheme developed specifically for this project. The scheme coded images for fit ideal body depiction, fitness focus, objectification, and sexualisation. Chi-square tests indicated that female fitness influencer content was more sexualised and portrayed more of the fit ideal, while fitness brands produced more Instagram content with a fitness focus. There were no significant overall longitudinal changes for any of the four key variables. However, when looking at longitudinal changes by account type, fitness-focused influencer content increased while fitness-focused brand content decreased over time. These findings highlight discernible differences in content produced by different Instagram account types. It points future research towards the consideration of potential moderating factors, such as account type, when exploring the impact of social media images on body image and mental health

The role of social support on physical activity behaviour in adolescent girls:A systematic review and meta-analysis

ABSTRACT: Adolescent girls have been targeted as a priority group for promoting physical activity levels however it is unclear how this can be achieved. There is some evidence to suggest that social support could impact the physical activity levels of adolescent girls, although the relationship is complex and not well understood. We aimed to systematically review and meta-analyse the relationship between social support and physical activity in adolescent girls, exploring how different types and providers of social support might influence the relationship. Articles were identified through a systematic search of the literature using 14 electronic databases, personal resources, grey literature, and reference lists of included studies and previous reviews. Search terms representing social support, physical activity and adolescent girls were identified and used in various combinations to form a search strategy which was adapted for different databases. Cross-sectional or longitudinal articles published in English that reported an association between social support and physical activity in adolescent girls between the ages of 10 to 19 years were included. Studies that focused only on clinical or overweight populations were excluded. Data extraction was carried out by one reviewer using an electronic extraction form. A random 25 % of included articles were selected for data extraction by a second reviewer to check fidelity. Risk of bias was assessed using a custom tool informed by the Critical Appraisal Skills Programme Cohort Study Checklist in conjunction with data extraction. Cross-sectional results were meta-analysed and longitudinal results were presented narratively. Small but significant associations between all available providers of total social support (except teachers) and physical activity were found (r = .14-.24). Small but significant associations were also identified for emotional, instrumental and modelling support for some providers of support (r = .10-.21). Longitudinal research supported the cross-sectional analyses. Many of the meta-analysis results suggested high heterogeneity and there was some evidence of publication bias, therefore, the meta-analysis results should be interpreted with caution. In conclusion, the meta-analysis results suggest that social support is not a strong predictor of physical activity in adolescent girls though parents and friends may have a role in enhancing PA. TRIAL REGISTRATION: PROSPERO 2014:CRD42014006738 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12966-016-0405-7) contains supplementary material, which is available to authorized users