The invention pertains to the establishment, implementation and management of a personalized information system pertinent to a user's general health, wellness and/or sport performance. A novel set of portable devices with calorimetric, metabolic sensing, computing and communication capabilities are used for non-stop real-time measurement and display as well as long-term logging of highly accurate information about a user's metabolic state. Continuous real-time feedback on the user's respiratory quotient (RQ) and other data may be provided. A novel dual-battery system is also provided by which an uninterrupted power supply can be provided for electronic components. The personalized information system is further designed to consider measured and calculated metabolic parameters in relation to manually specified, user-specific goal(s), and to provide feedback about the user's progress with regards to these goals over the short- and long term. The system may be used to continuously determine the real-time nutritional state, energy uptake and energy expenditure level of the user, and may provide subsequent personalized nutritional- and exercise guidance to advance the user's efficiency at achieving and maintaining his/her specific health, wellness and/or sport performance goal(s). The invention also integrates user information, such as, but not limited to real-time energy uptake and real-time energy balance with social networking/gaming and other social interactions.
