Abstract: This disclosure relates to a method of eliciting satiety (psycho phenomenetic sense of being filled) in mammals through the administration of an effective amount of a trypsin inhibitor and is based on the postulate that the enzyme trypsin, normally secreted by the pancreas, constitutes a negative feedback signal for cholecystokinin secretion which in turn comprises a putative satiety signal; thus, the effect of the trypsin inhibitor is to increase the concentration of cholecystokinin secretion advancing the sensation of satiety resulting in a consequent decrease in food intake and, over time, body weight.