An internal systems imbalance determining method for use in the determination of suitable food supplements provision for a patient, is provided. The patient has on his skin at least one sensing zone with at least one measurement point located therein, and at least one stimulation point. The method includes providing a diagnostic device for measuring electrical resistance between the measurement point on one side of the body, and a ground point on the other side of the body; providing at least one positioning member adapted to be placed over and at least partially cover the at least one sensing zone of the patient; placing the positioning member on the sensing zone on one side of the body; bringing the active electrode in contact with the measurement point through the positioning hole to provide the electrical signal thereto and providing electrical ground at the ground point by the dual-purpose electrode, and collecting a first measurement therefrom; removing the active electrode and electrically stimulating the body at the stimulation point using the dual-purpose electrode; repeating the above to collect a second measurement from the measurement point; performing analysis of the first and the second measurements thereby allocating possible imbalance of internal systems of the body; and outputting results of the analysis.