Feeding rate and responses to food deprivation as a function of fasting-induced hypoglycemia

The relation between hypoglycemia induced by 3 hr of food removal at various times throughout the day and the amount eaten during the corresponding ad-lib periods was examined in rats. It was found that the 3-hr-deprivation fall in blood glucose was different between the night and the daytime and also between the beginning and the end of the daytime. A highly significant correlation existed between the 3-hr ad-lib intake and this time-dependent fall in blood glucose. Moreover, the correlation between the same fall in blood glucose and increases in subsequent intakes after 3-hr deprivation was also significant. The conclusion is drawn that rats eat at a rate just required to prevent hypoglycemia under ad-lib conditions and that after food deprivation they transiently increase this rate to correct the fall in blood glucose and to reestablish the required supply of glucose to tissues.