Cephalic phase responses (CPRs) are conditioned anticipatory physiological responses to food cues. They occur before nutrient absorption and are hypothesized to be important for satiation and glucose homeostasis. Cephalic phase insulin responses (CPIRs) and pancreatic polypeptide responses (CPPPRs) are found consistently in animals, but human literature is inconclusive. We performed a systematic review of human studies to determine the magnitude and onset time of these CPRs.