The regional distribution of body fat has been identified as a significant risk factor for the development of noninsulin-dependent diabetes mellitus and cardiovascular disease (CVD). Several studies that have investigated the potential associations between topographic features of adipose tissue and indices reflecting carbohydrate and lipid metabolism have reported significant associations between abdominal fat deposition and metabolic complications. The development of computed tomography as a means to precisely measure the amount of subcutaneous and deep adipose tissue at any site of the body has shown that determination of the level of visceral adipose tissue is a critical measurement to perform in the assessment of the health hazards of obesity. Studies that we have conducted in premenopausal women have clearly shown that the level of visceral adipose tissue is the best correlate of lipoprotein ratios used to estimate the risk of CVD. We have also reported that a high level of visceral adipose tissue is associated with a deterioration of glucose tolerance and that the relationship between visceral fat deposition and glucose tolerance remains significant after controlling for the level of total-body fat. Because significant interrelationships were observed between abdominal visceral obesity, insulin resistance, and dyslipoproteinemias in obese women, it is suggested that visceral obesity is an important component of the insulin-resistance syndrome (syndrome X) that has been previously described. This cluster of morphological, hormonal, and metabolic alterations observed in abdominal obesity may have substantial implications for the treatment of this condition.