**Fig. (1)** **Abdominal Obesity index (ABOI) and central obesity.** The upper body cavity cylinder can be divided into the abdominal segment and the thoracic segment. C_{1} and C_{2} represent the circumferences of the thoracic segment and abdominal segment, respectively. To simplify the calculation of volumes, the heights (h) of the thoracic segment and the abdominal segment are considered the same. The volume of thoracic segment = h∙2πr^{2} in which r = ½C_{1} and the volume of the abdominal segment = h∙2πr^{2} in which r = ½C_{2}. = ABOI = [C_{2}]^{2}/[C_{1}]^{2}. Generally, the larger the ABOI is, the more severe the central obesity is.