Classification of Obesity. It has been noted that the incidence of metabolic complications among equally obese subjects differs depending on their physique (11) and there has been more scientific assessment in recent years that complications such as diabetes mellitus or hyperlipidemia are related to adipose tissue distribution (5). In 1983, we reported a method for adipose tissue analysis using computed tomography (CT), which enables the analysis of adipose tissue in the body cavity, e.g., abdominal cavity or thoracic cavity, as well as subcutaneous fat (10). Using this method, we found that the patients with accumulation of fat in the abdominal cavity have a higher incidence of complication (1). Based on this finding, we proposed a classification into visceral fat obesity by visceral fat area (V)/subcutaneous fat area (S) ratios obtained from CT cross sectional pictures of the umbilical region. We divided obese subjects at a V/S ratio of 0.4, classifying those with a ratio of 0.4 or more as a visceral fat obesity group and those with V/S ratio of below 0.4 as a subcutaneous fat obesity group. Disorders of glucose and lipid metabolism were more marked in the visceral fat obesity than subcutaneous fat obesity even when sex and age were matched. We also demonstrated that visceral fat obesity is more frequently accompanied by circulatory disorders such as left ventricular enlargement (8) and hypertension than subcutaneous fat obesity (2).