An object of the present invention is to provide a lipid metabolism improving agent, or to provide foods and drinks, food and drink additives, and feeds or feed additives for improving lipid metabolism. In order to achieve such an object, the present invention provides a lipid metabolism improving agent comprising hydroxyproline, a hydroxyproline derivative or a pharmaceutically acceptable salt thereof or foods and drinks, food and drink additives, feeds or feed additives for improvement of lipid metabolism comprising the same.