Post-absorptive plasma glucose concentration has been discovered to be physiologically maintained within the range of 70 mg/dl [3.9 mmol/l] to 110 mg/dl [6.1 mmol/l] in humans. This is accomplished via increased glucose levels from glucagon and decreased glucose levels from insulin.
Source: Boundless. “Postabsorptive State.” Boundless Anatomy and Physiology. Boundless, 19 Jun. 2015. Retrieved 24 Jun. 2015 from https://www.boundless.com/physiology/textbooks/boundless-anatomy-and-physiology-textbook/nutrition-metabolism-and-temperature-regulation-24/metabolic-body-states-232/postabsorptive-state-1153-5274/