Emotional eating—consuming food in response to emotions rather than hunger—is associated with cravings, overeating, and disordered eating. While emotion regulation (ER) is a known protective factor, most evidence comes from Western, laboratory-based studies. This study applied ecological momentary assessment (EMA) to examine how ER moderates real-time links between affect, cravings, and eating among Japanese students.　Eighty-four university students (aged 18-25) completed a seven-day EMA protocol via smartphone. Multilevel models showed that negative affect, particularly depressive mood (β = 0.29, p = .014) and anxious mood (β = 0.30, p = .013), significantly predicted cravings for salty snacks. Anxious mood was also weakly associated with overall eating episodes (β = 0.06, p = .058). Crucially, ER emerged as a consistent moderator. Higher ER attenuated the impact of negative mood on cravings (e.g., depressive mood × ER: β = -0.63, p = .004) and reduced affect-driven eating episodes (e.g., depressive mood × ER: β = -0.21, p < .001; stress × ER: β = -0.14, p < .001). In contrast, perceived stress alone was not a significant predictor of eating behavior.
These findings highlight ER as a robust protective factor, buffering against affect-driven eating in daily life. The study suggests that interventions strengthening ER may reduce vulnerability to cravings and overeating. Moreover, the EMA design illustrates the promise of real-time, technology-based tools (e.g., just-in-time adaptive interventions) for applied psychology and public health.