The present invention refers to data management unit comprising a data storage (130) adapted to store a plurality of measurement values of the physiological parameter, preferably a blood glucose level, for each measurement value an associated event tag, for each measurement value an associated time stamp, an associated time range for tagging preselection for each of at least two meal events, each time range is preferably user-settable, preferably also for a fasting event an associated time range for tagging preselection, this time range is preferably user-settable, a processor (140) adapted to receive a new measurement value from the data storage (130) or from a measurement unit (110), which is preferably at least shortly connected for data transfer, assign an associated time stamp to the new measurement value, if an associated time stamp does not yet exist with the new measurement value, receive selection data containing the information that the user has selected and/or confirmed one of a “before meal” tag and an “after meal” tag with regard to the new measurement value, automatically select an additional associated tag referring to one of the at least two meal events and preferably also of the fasting event based on the selection data and on a comparison of the time stamp of the new measurement value with the associated time ranges for tagging preselection of the at least two meal events and preferably also with the time range for tagging preselection of the fasting event. The invention further refers to a corresponding medical device (100), a corresponding method and computer program for operating a data management unit as well as to a corresponding computer program product.
