Central obesity with visceral fat accumulation and the amount of skeletal muscle mass may influence insulin sensitivity via its capacity for glucose load uptake. We investigated the relationships among the following metabolic variables: ratio of fat area to skeletal muscle area (VMR), percent ideal body weight, body mass index, waist-to-hip circumference (WHR) and visceral fat to subcutaneous fat ratio (VSR) in 114 nondiabetic middle-aged women. Anthropometric parameters, lipid profiles and sex hormone-binding globulin were measured. Visceral and subcutaneous fat areas at the umbilical level and the skeletal muscle area at the mid-thigh level were measured and computed. 75-gram OGTT tests were performed, along with measuring plasma glucose, insulin and free fatty acid levels, according to which area under the curve of glucose (Glu-AUC), insulin (Ins-AUC), free fatty acid (FFA-AUC) and glucose/insulin ratio (GIR=Glu- AUC/Ins-AUC), were calculated. 1) Triglyceride was more correlated with VSR than VMR. 2) The independent anthropometric parameters for each metabolic variable were In conclusion, VMR for Ins-AUC, WHR for Glu-AUC and total cholesterol, and VSR for triglyceride. 3) For subjects with higher VMR, age, Ins-AUC and triglyceride were significantly higher. 4) Subjects with higher VMR were older and showed higher Ins-AUC and lower GIR than the subjects with lower VMR. In conclusion, VMR is an anthropometric parameter that reflects insulin resistance concerning glucose metabolism, and VSR is thought to be a good parameter that that reflects the serum lipid levels. Further prospective studies are necessary to reevaluate the visceral fat vs. skeletal muscle relationship.