The present invention provides antibodies that bind to the human glucagon receptor, designated GCGR and methods of using same. According to certain embodiments of the invention, the antibodies are fully human antibodies that bind to human GCGR. The antibodies of the invention are useful for lowering blood glucose levels and blood ketone levels and are also useful for the treatment of diseases and disorders associated with one or more GCGR biological activities, including the treatment of diabetes, diabetic ketoacidosis, long-term complications associated with diabetes, or other metabolic disorders characterized in part by elevated blood glucose levels, including stress hyperglycemia.