A safe, economical, and convenient food or drink having the effect of treating, preventing, or improving diabetes or diabetic complications without involving significantly changed dietary life habits is provided. A food or drink is provided for treating, preventing, or improving diabetes or diabetic complications, comprising oligosaccharides at a concentration of 0.15 to 10% by weight wherein the oligosaccharides include mannose molecules linked together with degree of polymerization of 2 to 10 (inclusive).本發明提供具有治療、預防或改善糖尿病或糖尿病併發症之效果的安全、經濟及便利的食品或飲料，而不會涉及明顯改變的飲食生活習慣。食品或飲料係提供用於治療、預防或改善糖尿病或糖尿病併發症，其包括濃度0.15至10重量%的寡糖，其中寡糖包括以聚合度2至10(含)連結在一起的甘露糖分子。
