A wearable device comprising: a memory configured to store product codes for consumable products and data indicating respective product recommendations or from which product recommendations can be derived； a product code reader for reading product codes from products； one or more inertial sensors for obtaining motion data for a wearer of the device； a visual indicator for providing a visual indication of a product recommendation, using data stored in the memory, in response to a read product code. The wearable device further comprises a processor configured to process the motion data to identify periods when the wearer is in a sitting position or other sedentary state, analyze the occurrence and durations of the periods, and modulate the recommendations accordingly for at least a subset of the product codes, whereby product recommendations change depending upon the identified periods.
