a diabetes care management system for managing blood glucose levels associated with diabetes comprising a computing device and an insulin delivery device . the computing device generally includes a memory comprising one or more optimal blood glucose values , one or more self care values of a patient , one or more measured blood glucose values , and one or more scaling factors for weighting the impact on a future blood glucose value and that are customizable to an individual patient to predict the effect on the blood glucose of self care actions performed by the individual patient ; a microprocessor , in communication with the memory , programmed to determine the one or more scaling factors from one or more physiological parameters including body mass , metabolism rate , fitness level or hepatic or peripheral insulin sensitivity , or combinations thereof , and calculate a further value , the further value being based on the self care values , and on the one or more optimal blood glucose values , and on the one or more scaling factors ; and a display configured to display information according to the further value ; and a housing , wherein the memory and the microprocessor are housed within the housing , thereby providing a hand - held , readily transportable computing device . the insulin delivery device may deliver insulin in response to information associated with the further value .