Three studies were conducted to test the behavioral consequences of effortful self-regulation. Individuals with chronic inhibitions about eating were exposed to situations varying in level of self-regulatory demand. Subsequently, participants' ability to self-regulate was measured. Two studies manipulated self-regulatory demand by exposing participants to good-tasting snack foods, whereas a third study required participants to control their emotional expressions. As hypothesized, exerting self-control during the first task led to decrements in self-control on a subsequent task. Moreover, these effects were not due to changes in affective state and occurred only when self-control was required in the first task. These findings are explained in terms of depletion of self-regulatory resources, which impairs successful volitional control.