A metabolic energy monitoring system having one or more physiological measurement platforms and displays enabling the calculation and display of energy balance, kilocalorie energy expenditure and kilocalorie intake is described. In preferred embodiments, the system utilizes one or more on-body monitoring platforms to enable measurement of change in body composition and kilocalorie energy expenditure over a period of time thereby enabling a comparator to calculate net energy balance over this period of time and to calculate kilocalorie intake over this same period of time. Such data may then be displayed on a display device in wireless communication with the on-body monitoring platform to provide the user of the system with useful information and guidance in weight management applications.