The COVID-19 pandemic has accelerated the adoption of digital healthcare and highlighted the importance of patient-centred lifestyle management for chronic conditions. However, the current focus primarily concerns health professionals and disease prediction models, neglecting the comprehensive consideration of patients' lifestyle factors. This results in a lack of models for lifestyle management and a scarcity of studies exploring the inter-relationships among different lifestyle factors within patient-centric self-management systems. Consequently, the holistic management of chronic conditions is hindered, as lifestyle factors are not adequately addressed. To address these issues, this study utilises diabetes as a case study to develop interrelated models that encompass both the behavioural aspects of lifestyle factors and the biological impacts on individual health and wellness. Through system dynamics modelling techniques, this research aims to provide a holistic understanding of the complex interactions within a patient's life and enable personalised management and care.