One variation of a method for tracking consumption of supplements by a user includes, at a software program executing on a mobile computing device: receiving a selection of a supplement, from a set of known supplements, contained in a supplement package of a particular packaging format; loading a supplement profile of the supplement into a user profile; rendering an instruction for placement of a tracker on the supplement based on the packaging format; retrieving a motion model, from a set of motion models for characterizing a consumption event at the packaging format; and uploading the motion model to the tracker. The method also includes, at the tracker: characterizing motion of the supplement package as a consumption event based on the motion model; and transmitting a time of the consumption event to the mobile computing device.