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.