A user's personal biometric information such as age, sex, weight, height as well as the user's lifestyle information, such as daily caloric input, job description, smoker status and physical fitness, is uploaded onto a host computer. Target heart rate, energy and/or caloric consumption levels related to desired fitness and weight loss goals for a particular individual are then selected having regard to fitness levels for an individual of comparable age, and consuming similar calories are then downloaded to a caloric monitoring unit. The caloric monitoring unit is provided for measuring the user's heart rate and dynamic energy and/or caloric expenditure over one to four weeks. The caloric monitoring unit includes a heart rate monitor, a unit accelerometer, a global positioning system (GPS), and an audio and/or video output. The audio/video output is operable to provide information and/or motivational prompts to the user in the event the heart rate, energy expenditure and/or caloric expenditure falls below or exceeds pre-selected target expenditures over a particular time segment of the selected time period having regard to the calories which are consumed. A display provides a continuously updated visual indication of whether or not the use has achieved the pre-selected optimum caloric burn or energy expenditure for that particular time segment. An internal calendar/clock, a processor and/or memory in the caloric monitoring unit compares measured heart rate and energy expenditures for multiple time segments against target levels stored as the user-specific fitness programme tailored to achieve the desired weight loss. The comparison is then used to generate compliance output data to either the user and/or a nutritionist.