Physiological signals inhibiting appetite for food, detected by difference between expected and actual satiety at a specified time after a meal

‘Surprise satiety’ is a measure of the momentary state of physiological signals to the brain that inhibit appetite for food. These unpredicted components of satiation processes were measured after the first intake of a familiar food made with forms of fat and carbohydrate that were not usually included. Expected satiety was assessed at the end of eating and cues from food in the mouth, as predictions of appetite for a between-meals food after specified delays. The actual satiety eventuating at each of those times was assessed by the same quantitative judgments of hunger state. An underestimate of the satiety at a particular delay should reflect the strength of signals at that time from assimilation of the unusual constituents, subject to the eater’s personal interpretation of any earlier cues. Emulsified fat generated unpredicted satiety sooner than unemulsified oil, likely in part at least because the oil floats on the chyme and so is delayed in the stomach instead of being emptied with the aqueous phase. Slowly digested bean starch gave much later surprise satiety than did sugar or grain starch. When surprise satiety had occurred, the next consumption of that recipe induced less unpredicted inhibition of appetite, indicating some one-trial learning of time-specified expectations of postprandial satiation processes.