Can healthy food-choice habits protect people against temptations of consuming large portion sizes and unhealthy foods? In two studies, we show that the answer is yes, good habits serve this protective role, at least in contexts in which people are not deliberating and thus fall back on habitual responses. In the first study, participants trained with unhealthy habits to approach eating chocolate, but not those trained with healthy habits, succumbed to temptation and ate more chocolates when their self-control resources were depleted. Study 2 extended and clarified these findings by demonstrating the role of environmental cues in eliciting healthy habits when self-control resources are depleted. Participants who had been trained to choose carrots habitually to a pictorial stimulus (i.e., habit cue) subsequently resisted choosing M&Ms as long as the cue was present. This effect of habit cues on healthy food choices suggests the usefulness of manipulating such cues as a means of meeting self-regulatory goals such as portion control.