Disclosed herein is the use of a composition, containing isoflavone-containing soybean extract, L-carnitine, caffeine and arginine as active ingredients, for the treatment of obesity and diabetes. The disclosed composition contains isoflavone-containing soybean extract, carnitine, caffeine and arginine in the form of a mixture, and thus shows not only the effect of promoting lipolysis and fat burning, but also anti-obesity and anti-diabetic effects by increasing the expressions of adiponectin and Glut4 genes to restore insulin sensitivity.