Devices and methods are provided for non-invasive goal oriented and personalized monitoring of substance consumption directed towards aiding reduction of substance intake by a user. Based on the substance consumption characteristics and the user's profile, the user's substance consumption profile is identified and average amount of the substance in the body at a given time is computed. A threshold corresponding to amount of substance the body can sustain is then computed based on goals set by the user and the substance consumption characteristics and the user's profile. Alerts can be generated and transmitted to the user based on pre-determined conditions to help the user achieve his set goals.