Systems, techniques and methods for estimating the metabolic state or flux, e.g., the body energy state (“BES”) of a patient, are disclosed. The BES provides deep insight into the nutritional needs of the patient, thus allowing for a sort of exquisite glycemic control with regard to the patient. The invention discloses systems and methods for estimating fractional gluconeogenesis, which is the % of glucose production that comes from gluconeogenesis (“GNG”), as opposed to glycogenolysis (“GLY”), the other form of glucose production. Nutritional formulations, materials, cocktails and methods for feeding patients by parenteral and other means are disclosed. The amount, type and rate of such nutritional feeding are typically based upon the above estimating. The invention discloses formulations that contain labels, such as deuterium, for medical diagnostics, such as for estimating BES and fractional gluconeogenesis. The invention is suitable for any sort of patient, including those who are injured, such as with traumatic brain injury, ill, or have other conditions that stress the metabolic system.
