People engage in multiple behaviors that affect their health. There is little research on how these behaviors intersect within a person’s life. In this dissertation, I hypothesized that behaviors that activate the neural reward system can “compete.” In Study 1, I experimentally tested if eating sweet high-fat foods acutely reduced alcohol cravings for heavy drinking adults. I found that eating sweet high-fat foods acutely reduced alcohol cravings no more than watching a neutral video. In Study 2, I observed multiple reward-related behaviors (e.g., self-affirmation, social interactions, exercise) and health-compromising behaviors (e.g., unhealthy eating, alcohol use) within the everyday lives of young adults via a 4-day ambulatory electronic diary. I found that when young adults engaged in multiple reward-related behaviors they were more likely to eat unhealthy foods in the next hour. However, when young adults engaged in reward-related behaviors that provided a sense of accomplishment they were less likely to drink alcohol in the next hour. These studies fill scientific gaps in understanding intersections between reward-related behaviors and provide insight for health behavior change. Namely, that “replacing” health-compromising behavior with other reward-related behaviors may not consistently work.