Social network influences and the adoption of obesity-related behaviours in adults: a critical interpretative synthesis review

BACKGROUND: Obesity is a key risk factor for developing a long-term condition and a leading cause of mortality globally. The limited evidence associated with interventions that currently target obesity-related behaviours demand new approaches to tackle this problem. Given the evidence that social ties are implicated in the gaining and reduction of weight, the use of social networks in interventions is potentially a novel and useful means of tackling this health issue. There is a specific gap in the literature regarding what and how social network properties and processes together with environmental and individual factors influence the adoption of positive and negative obesity-related behaviours in adults. METHODS: To address this gap in developing an integrated and holistic conceptual approach, a critical interpretative synthesis was undertaken following a line of argument synthesis as an analytical strategy. RESULTS: Twenty-four studies were included. The data-driven themes meso-micro network processes, contextual and individual factors, and types of ties and properties were identified individually as components and causes of different health scenarios. Nevertheless, these drivers do not act on their own. As a consequence, developing multi-agent coalitions considering cross-level influences between the data-driven themes are two mechanisms that are created to understand more in-depth how social networks and the environment influence the adoption of obesity-related behaviours. These two new constructs point to a dynamic multilevel set of influences between multiple constructs, developing scenarios where positive and negative health results are identified. CONCLUSIONS: This critical interpretative synthesis offers a new means of exploring the application of social network properties and mechanisms in the ‘obesity’ field. The synthesizing argument created during the analysis process might be considered by health policy-makers, who might need to contemplate the wider open system of socially connected individuals and harness these forces to design new interventions where social networks and other contextual and individual factors operate together in a complex multilevel environment influencing obesity-related behaviours and practices. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12889-019-7467-9) contains supplementary material, which is available to authorized users.