Sensitivity of Bioelectrical Impedance Analysis (BIA) measurement was investigated in this study. Limb segments and the trunk of the body are usually assessed for the whole body impedance in the common-used eight-electrode system. However, even though the trunk is the largest part, the measurement sensitivity of the trunk part is extremely low resulting in low trunk impedance. In this study, a ten-electrode BIA system is proposed to improve the sensitivity of the trunk region by adding two more electrodes at the abdomen and proposing a new measurement scheme. Simulation results showed that the proposed system improved the sensitivity in the trunk region by 3.4–4.2 times. With the eight-electrode system, the content of a body segment could also affect the measured impedance of the other segments, but this effect was substantially reduced in the proposed system. The simulation results were confirmed by a phantom experiment on a piece of pork.