People often want to eat healthily but fail to do so. Sometimes people try and fail to exert control over unwanted food choices. But failing to eat healthily might also happen for a different, largely ignored reason: when encountering conflict between healthy and unhealthy food, people might fail to respond and initiate self-regulation. Accordingly, we tested in three studies (total N = 542) if how responsive participants are to conflict between healthy and unhealthy food is an important part of eating regulation. We developed a conflict response measure that indicates responsiveness to conflict between healthy and unhealthy food via post-conflict slowing. We then show that the stronger participants are committed to healthy eating, the more they slowed down after goal-relevant conflict (Study 1, 2) but not after goal-irrelevant conflict (Study 2). Importantly, goal-relevant, but not goal-irrelevant, post-conflict slowing predicted subsequent healthy eating in participants’ everyday life (Study 2). Finally, planning to act on a healthy eating goal via an implementation mindset manipulation increased post-conflict slowing compared to when healthy eating was deliberated (Study 3). Our findings suggest that conflict responsiveness might be important for understanding how people initiate self-regulatory processes.