The present specification includes, amongst other things, a portable monitoring device to calculate caloric intake, the monitoring device comprising (i) a housing, such as a bracelet, having a physical size and shape that is wearable on the human body, (ii) a blood glucose sensor, disposed in the housing, to generate data which is representative of the blood glucose concentration of the user, (iii) a blood triglycerides sensor, disposed in the housing, to generate data which is representative of the blood triglycerides concentration of the user, and (iv) processing circuitry, disposed in the housing and coupled to the blood glucose sensor and/or blood triglycerides sensor, to calculate caloric intake using data representative of the blood glucose concentration and/or blood triglyceride concentration of the user.