Background: The prevalence of Gestational Diabetes Mellitus (GDM) is increasing globally and the link between GDM, obesity and the development of Type 2 Diabetes Mellitus (T2DM) in later life is increasingly recognised by international health authorities. Previous research suggests that strategies aimed at postpartum women and designed to promote weight loss through increased physical activity and dietary modifications may be feasible. However, recruitment and engagement of this cohort has met with differing success. Development of an evidence-based program that encourages behaviour modification resulting in weight loss may delay or prevent T2DM in this cohort. Method: Following a review of the literature, a mixed method approach was employed. A randomised controlled trial (RCT) of a behaviour modification intervention (which combined a pedometer web-based program with nutrition coaching) was conducted over a three month period. The primary outcome for the RCT was weight loss, and secondary outcomes included; improved insulin sensitivity, increased physical activity, improved diet quality and self-efficacy, decreased waist and hip measurements, and a decreased Free Fat Mass (FFM).Qualitative data collected through semi structured interviews conducted after the intervention, were thematically analysed to examine the women's experiences of the intervention, barriers and enablers to participation, and to identify T2DM risk perceptions.Sample: Women with a BMI >25kg/m 2 , previously diagnosed with GDM were invited to participate six months (up to two years) postpartum.