The invention provides one or more agents that increase central dopaminergic neuronal activity selected from bromocriptine, lisuride, hydergine, dihydroergocriptine and/or dihydroergotoxine, plus a first-phase insulin secretagouge (FPIS), for use in treating prediabetes, Impaired Fasting Glucose, Impaired Glucose Tolerance or Type 2 Diabetes, wherein the FPIS is glucagon like peptide-1 (GLP-1), insulin or a GLP-1 receptor agonist, wherein said agent is administered to a human to increase central dopaminergic activity primarily within 4 hours of waking in the morning.