BACKGROUND. Optimal glucose control can prevent/relent tissue damage in patients with type 1 diabetes mellitus (T1DM). Ongoing efforts aim at developing closed loop control (CLC) algorithms linking subcutaneous continuous glucose monitoring (CGM) and insulin delivery (CSII). Substantial improvement towards an effective artificial pancreas system is still needed, especially in the regulation of post-meal glucose. Application of metabolic control analysis (MCA) can unveil and quantify distortions in the system properties of the glucose-insulin (pump) system (GIS), by measuring the coefficients of control (CCs) of glucose. Our approach rely on previous experience with our previous pilot protocol (NCT01800734).