Classification of Obesity. It has been noted that the incidence of met
abolic 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 hyperlipi
demia are related to adipose tissue distribution (5). In 1983, we repo
rted a method for adipose tissue analysis using computed tomography (C
T), 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 viscera
l fat obesity by visceral fat area (V)/subcutaneous fat area (S) ratio
s obtained from CT cross sectional pictures of the umbilical region. W
e 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 match
ed. We also demonstrated that visceral fat obesity is more frequently
accompanied by circulatory disorders such as left ventricular enlargem
ent (8) and hypertension than subcutaneous fat obesity (2).