The present invention addresses the problem of providing a sugar and/or lipid metabolism-improving agent. The problem is solved by a sugar and/or lipid metabolism-improving agent that contains fibrous paramylon.本發明之課題在於提供一種糖及/或脂質的代謝改善劑,利用含有纖維化裸藻澱粉(paramylon)之糖及/或脂質的代謝改善劑而解決。