Abstract: The present invention describes the use of fish protein (namely cod protein) and soy protein to improve the peripheral insulin resistance in a human or non-human animal. Fish and soy protein were administered to rats submitted to high-sucrose or high-fat/sucrose diets, which are animal models for diabetes. It was found that fish and soy protein efficiently control glucose utilization, and that fish protein is particularly effective in muscle tissue. This effect is not observed when rats are given casein. Fish and soy protein are therefore promising for controlling insulin-resistance, diabetes and complications resulting therefrom, such as obesity.