Eating nutritious foods and being more physically active prevents significant illnesses such as cardiac disease, stroke, and diabetes. However, leading a healthy lifestyle remains elusive and obesity continues to increase in North America. We investigate how online social networks (OSN) can change health behaviour by blending theories from health behaviour and participation in OSNs, which allow us to design and evaluate an OSN through a user-centred design (UCD) process.

We begin this research by reviewing existing theoretical models to obtain the determining factors for participation in OSNs and changing personal health behaviour. Through this review, we develop a conceptual framework, Appeal Belonging Commitment (ABC) Framework, which provides individual determinants (Appeal), social determinants (Belonging), and temporal consideration (Commitment) for participation in OSNs for health behaviour change.

The ABC Framework is used in a UCD process to develop an OSN called VivoSpace. The framework is then utilized to evaluate each design to determine if VivoSpace is able to change the determinants for health behaviour change. The UCD process begins with an initial user inquiry using questionnaires to validate the determinants from the framework (n=104). These results are used to develop a paper prototype of VivoSpace, which is evaluated through interviews (N=11). These results are used to design a medium fidelity prototype for VivoSpace, which is tested in a laboratory through both direct and indirect methods (n=36).

The final iteration of VivoSpace is a high fidelity prototype, which is evaluated in a field experiment with clinical and non-clinical participants from Canada and USA (n=32). The results reveal positive changes for the participants associated with a clinic in self-efficacy for eating healthy food and leading an active lifestyle, attitudes towards healthy behaviour, and in the stages of change for health behaviour. These results are further validated by evaluating changes in health behaviour, which reveal a positive change for the clinical group in physical activity and an increase in patient activation. The evaluation of the high fidelity prototype allow for a final iteration of the ABC Framework, and the development of design principles for an OSN for positive health behaviour change.