A series of experiments was performed to further understand the behavioral and physiological determinants of postfast anorexia in golden hamsters. Postfast anorexia and/or the failure to adapt to a feeding schedule was not restricted to a particular photoperiod condition or strain of hamster. The anorexia was also observed with a liquid diet, but hamsters were able to show large increases in water intake on a water deprivation schedule. When the animals were group housed, they pouched food during scheduled feeds and ate it later: Meal size was not increased. Measures of gastric fill and plasma metabolites indicated that filling and emptying of the forestomach may occur with a periodicity similar to that of spontaneous meals, and the data were consistent with strong peripheral satiation/satiety mechanisms in this species.