[Problem] To provide an agent suppressing an increase in blood sugar level, said agent being capable of controlling blood sugar level even in a patient having normal blood sugar level or a patient corresponding to pre-diabetes, showing little side effects and being derived from a safe food. Also, the present invention addresses the problem of providing foods and drinks, i.e., foods including health foods, functional foods, health supplements, etc. as well as drinks, each comprising the aforesaid composition. [Solution] An extract of yeast to be used as an active ingredient. As the extract of yeast, it was found that a yeast extract, which can be obtained by a simple procedure comprising treating a yeast with hot water, an acid or an alkali, and/or an enzyme, has an improved effect of suppressing an increase in blood sugar level.
