A portable ketone measurement device measures ketone levels in breath samples or other bodily fluid samples of a user, and communicates the ketone measurements to an application that runs on a smartphone or other mobile device of the user. The application may communicate with, and report the measurements to, a remote server. One or more components of the system (e.g., the portable ketone measurement device, the mobile application, and/or the server) may, where appropriate, adjust the ketone measurements to compensate for ketone variations resulting from, e.g., the age of the user, a medical condition of the user, a missed medication event, or an interrupted sleep event. The application may, in some scenarios, withhold the display of a ketone measurement from the user until an authorization has been received from the server.