Unhealthy snacking is considered one of the main contributors to the current obesity pandemic. Initial research suggests that work-related stress may be an important predictor of unhealthy snacking, however, there is still much to learn about the underlying mechanisms and conditions of work-related snacking. To address this research gap, we investigated the effect of two prominent work stressors, workload and interpersonal conflict, on unhealthy snacking behaviors during work and in the evening after work. We propose that these effects may be explained through a homeostatic motive to restore energy following depletion and a hedonic motive to induce pleasure, thus investigating the potential mediating effect of emotional exhaustion and negative affect. Additionally, since individual differences play an important role for snacking behaviors, we examined the potential moderating effect of trait mindfulness. Results from diary data across two workweeks (N = 118) did not show a significant positive linear relationship between daily work stressors and unhealthy snacking. The protective nature of trait mindfulness became apparent in the relationship between after-work emotional exhaustion and unhealthy snacking, indicating that individuals high in trait mindfulness consume less unhealthy snacks in the evening after work when emotionally exhausted. Furthermore, a supplementary analysis revealed that employees especially snack in the evening after low workload days. Taken together, our results unfold the complex nature of work-related snacking and offer valuable input for practical implementations.