To provide a goal setting person (a user) with a method for predicting blood sugar level which offers appropriate information and support for goal achievement.

The method for predicting blood sugar level by means of a management server for managing blood sugar level information from a plurality of terminals comprises: an authentication step for determining whether communication with the terminals is allowed or not; a blood sugar level information obtaining step for obtaining the blood sugar level information from the authenticated terminals; prediction curve calculating steps (S10 and S13) for calculating respective blood sugar level prediction curves on the basis of the blood sugar level information from the terminals; and an information sharing step for enabling mutual exchange of the information on the blood sugar level and the blood sugar level prediction curves among the terminals.