Binge eating disorder (BED) and bulimia nervosa (BN) are characterized by binge eating. Frequently related to negative affect, binge eating is considered unwanted eating behavior. It is often preceded by a shift away from the goal of a healthy eating pattern. Implementation intentions are 'if-then' plans that may prevent such shifts in goals. In a students' sample with subthreshold binge eating, two implementation intention conditions were compared to a control condition in which only goals were formed. In the behavior-focused condition, implementation intentions targeted binge eating; in the emotion-focused condition, implementation intentions targeted negative affect preceding binge eating. All participants received three sessions and kept food diaries for four weeks, followed by a post-test and a one-month, three-months, and six-months follow-up. Compared to the control condition, both implementation intention conditions showed significant and large reductions in binge eating lasting for six months. Effects did not differ between both implementation intention conditions. Three implementation intention sessions reduced subthreshold binge eating. This continued for six months after the final session. Contrary to expectations, behavior-focused and emotion-focused implementation intentions were equally effective, possibly due to other triggers than negative affect. Future research should address their usefulness in BED and BN.