Sham feeding as a procedure for assessing the influence of diet palatability on food intake

Most of the methods used to evaluate the role of taste factors on food intake are confounded by the postingestional consequences of the ingested diet which interfere with measurements of consumption based strictly upon the stimulus properties of the food. The present experiment examines the utility of sham feeding in the gastric fistulated rat as a means of isolating, and thereby evaluating, the contribution of hedonically positive (sweet) and hedonically negative (bitter) taste factors on the magnitude of food intake. Rats equipped with open gastric cannulae sham fed solutions varying in their sucrose or quinine concentrations. The results revealed that the magnitude of sham feeding in a fixed time period varied systematically with the taste properties of the food. It is concluded that sham feeding represents a useful technique for isolating the influence of diet palatability on food intake. Furthermore, the present data identify one of the parameters that influences the magnitude of the sham feeding response, information that is important for studies using this preparation as a means of examining oral sensory controls of food intake control systems.