Free fatty acids (FFA), triglycerides, cholesterol, and blood FFA levels were studied in the glucose tolerance test (GTT) in 63 women with adiposity combined with normal and diabetic GTT, and in those suffering from manifest diabetes mellitus during reduction of body weight and normalization of carbohydrate metabolism. It appeared that normalization of body weight and of glycemia on fasting stomach and in the course of the day led to a significant normalization of the FFA, triglycerides, and cholesterol levels. Normalization of body weight alone with persisting GTT disturbances caused a significant normalization of the triglyceride and cholesterol levels; as to the FFA they remained significantly elevated. GTT normalization with persisting adiposity led to reduction of the triglycerides, cholesterol, and FFA levels, but they still significantly exceeded the parameters in healthy persons. The curve of the FFA reduction following glucose load became normal with the weight and GGT normalization, and remained delayed in cases with no loss of body weight. The data obtained permitted to draw a conclusion on the leading role of the body weight reduction in the normalization of lipid metabolism in these patients.