Administration of mannoheptulose (MH) at a concentration of 200-300 mg./kg. body weight, administered intraperitoneally or intracardiacly resulted in a significant increase of plasma glucose concentration (24.3%) four hours after administration. Food consumption was effected by administration of 300 mg./kg. body weight. There was a significant reduction in the mannoheptulose treated animals compared to the saline controls during the second and third hours of testing. The results were similar to those reported for mammals although the increase in plasma glucose concentration was not as drmatic in birds as it is in mammals. Food consumption studies in rat indicate a suppression, however, it is not significant as it was in this study.