A monitoring system for alerting a user to the negative effects of sedentary behaviour, comprising: a memory storing product codes for consumable, topically applied, and/or body-worn products, and data indicating respective product recommendations or from which respective product recommendations can be derived and one or more processors. The one or more processors are configured to: monitor the behaviour of the user by using motion data obtained from one or more inertial sensors worn by the user to identify periods when the user is in a sitting position or other sedentary state； and based on the behaviour of the user, select from at least a subset of the product codes, product codes for which the respective product recommendation is to be modulated. The monitoring system also comprises a visual indicator controllable by the one or more processors to provide a visual indication dependent on the number of selected products codes.
