Background Limited resources make prevention of complex population-level issues such as obesity increasingly challenging. Collaboration and partnerships between organisations operating in the same system can assist, however, there is a paucity of research into how relationships function at a local level. The aim of this study was to audit initiatives, explore networks, and identify potential opportunities for improving the obesity prevention system in a Health Service area of Western Australia (WA). Methods A mixed-methods study was undertaken in a metropolitan Health Service in Perth, WA in 2019–20. Structured face-to-face interviews (n = 51) were conducted with organisations engaged in obesity prevention, to identify prevention initiatives and their characteristics using a Systems Inventory tool. The Research Team identified the 30 most active organisations during the Systems Inventory, and an online Organisational Network Survey was administered to explore: relationships across six domains; partnership duration; frequency of interaction with other organisations; barriers to implementation; and key contributions to obesity prevention. Descriptive statistics were used to summarise barriers, contributions and Systems Inventory data. Organisational Network Survey data were analysed using social network analysis through UCINET 6 for Windows and Netdraw software. Whole network and cohesion scores were calculated: average degree; density; diameter; and degree centralization. Core-periphery analysis was conducted to identify densely connected core and sparsely connected periphery organisations. Results The Systems Inventory identified 189 unique prevention initiatives, mostly focusing on individual-level behaviour change. Fifty four percent (n = 15) of the Organisational Network Survey respondent organisations and most core organisations (67%, n = 8) were government. The information and knowledge sharing network had a density of 45% indicating a high level of information and knowledge exchange between organisations. The lowest densities were found within the receiving (3.3%), providing (5.5%) and sharing (5.6%) funding networks, suggesting that these formal relationships were the least established. Conclusion Applying a systems thinking lens to local obesity prevention revealed that initiatives conducted focused on individual-level behaviour change and that collaboration and communication between organisations focused on information sharing. Capturing the extent and nature of initiatives and the way partnerships operate to improve obesity prevention can help to identify opportunities to strengthen the networks.

The industry marketing code requires age-restriction controls to be activated for alcohol advertising on social networking sites to prevent children's access, however 28% of Instagram and 5% of Facebook accounts for alcohol brands owned by the nine dominant alcohol companies in Australia did not have controls activated • Industry self-regulation of alcohol marketing is not preventing children's access to alcohol content on social networking sites, demonstrating the need for a more effective, government-led regulatory approach

This study aimed to use systems thinking tools to understand network relationships to inform discussions, policy, and practice to improve nutrition, physical activity, and overweight/obesity prevention activities in a Western Australian local government area. An audit of nutrition, physical activity, and obesity prevention activities was conducted, and identified organizations were invited to participate in an organizational network survey. Social network analysis (SNA) determined the extent to which organizations shared information, knowledge, and resources; engaged in joint program planning; applied for and shared funding; and identified operational barriers and contributors. SNA data were mapped and analyzed using UCINET 6 and Netdraw software. Five organizations within the network were identified as core; the remainder were periphery. The strongest networks were sharing information, and the weakest was funding. The connections were centralized to one organization, enabling them to readily influence other organizations and network operations. Remaining organizations indicated limited partnership across the networks. Strengthened collaborations and partnerships are essential to health promotion, as they extend reach and organizational capabilities. This study provides a process for undertaking network analysis, identifying leverage points to facilitate communication and information sharing, and reorienting of collaborations and partnerships to consolidate scarce resources and act strategically within a bounded area. There is a need for stronger relationships between organizations and a reorientation of partnerships to facilitate resource sharing within the local government area, to improve nutrition, physical activity, and obesity prevention practices. SNA can assist in understanding organizational prevention networks within a bounded area to support future planning of practices and policy.