Diabetes, a disease characterised by high blood glucose levels, affects almost half a billion people worldwide and causes over 8 percent of global deaths. It doubles the risk of cardiovascular disease (CVD), causes 2.6% of global cases of blindness, 80% of all cases of end-stage renal disease, and increases the risk of lower-extremity amputations up to 20-fold. Diabetes caused additional worldwide healthcare costs of USD 760 billion in 20192, and reduces labour productivity in low-, middle- and high-income countries. This project aims to complement this evidence by addressing the challenge of diabetes focusing on the role of behaviour change after a diabetes diagnosis. The main goals are to (1) identify the change in health behaviours as a result of a diabetes diagnosis; (2) identify socio-economic and demographic characteristics that, together with clinical factors, affect the uptake of healthier behaviours and (3) identify the contribution of behaviour change to changes in risk factors for the other diseases resulting from diabetes. Taken together, the resulting insights will help inform the design of more effective policies to increase behaviour change in people with diabetes. The project was terminated prior to its complete conclusion and only one objective could be achieved during the project time. The results of the analysis show that in all three regions (the US, England and continental Europe), health behaviours (smoking and physical activity) remain mostly unaffected by a diabetes diagnosis. Smoking is reduced shortly after the diagnosis but returns to pre-diagnosis levels as time progresses. Physical activity levels remain unchanged. Body fat as measured by body mass index, however, decreases significantly in all surveys after the diagnosis and this reduction continues over time.