A method (400) controls the delivery of insulin in a diabetic patient (P) based on data (d) representative of at least a fraction of a meal (m(k+i)) that the patient (P) will consume. The method provides from a block (R) representative of conventional therapy or open loop rule that the patient (P) is subject to, based on the data (d) representative of at least a fraction of the meal (m(k+i)), a reference insulin value (u0). The method is also based on data representative of the difference between input data (ŷ), a reference glycemic level, and feedback data (yCGM) representative of the glycemic level detected in the patient (P). A control module (301; 401) provides a value of insulin (i) to be delivered to the patient (P) based on the various representative data.