A medical device having an impedance measurement circuit connected to at least two intracorporeal measurement electrodes arranged to measure the impedance of tissue inside the body of a patient. The impedance measurement circuit is adapted to apply a measurement current/voltage signal to the electrodes to measure and calculate the impedance of the measurement tissue, and to apply the calculated impedance value to a storage unit. The stored impedance values are used, by an analysis unit, to measure the amount of visceral fat of the tissue object inside the body of the patient.
