The effect of small amounts of oral glucose on hepatic function during starvation was studied. A group of 20, nondiabetic, obese, male patients were entered into the protocol. Ten were placed on absolute caloric starvation and the other ten were placed on a starvation diet modified by the daily addition of 8 or 16 g of oral glucose. Five patients in the starved group crossed over to the modified starvation protocol and 3 of the modified starvation group were switched to the starvation group at the end of the initial dietary period. Total serum bilirubin, serum glutamic pyruvic transaminase (SGOT) and lactic dehydrogenase (LDH) were significantly lower in the modified starvation group compared to the totally starved group. When the groups crossed over the values were similarly altered; the bilirubin and SGOT reduced with the addition of small amounts of glucose and were elevated with starvation. Fasting immunoreactive insulin (IRI), glucagon, and glucose were similar in both groups; but the 90-min postprandial IRI was doubled while only a 15 mg/dl change in blood sugar was seen. The results show that small amounts of oral glucose reduces the total serum bilirubin, SGOT, and LDH elevation of starvation. It is suggested that the postprandial increase in peripheral IRI seen in modified starvation may expose the liver to pulses of portal vein insulin that may exert a protective effect thru the known hepatotrophic effects of insulin.