The company, DataArt, is developing technology that will take an image of the food you eat and look up the calorie content. This approach is a logical next step in passive acquisition of caloric data, but it seems inelegant and cumbersome. With the advances in sensor technology that are taking place, it shouldn’t be long until actual calories consumed can be measured. Such a sensor will probably have to be implanted rather than worn, but implantable/injectable sensing devices is where the future of body-monitoring sensors are headed.