Mechanisms of emotional eating: food approach bias covaries with affect on days with high food craving

Emotional eating (EE) - eating in response to emotions - has clinical relevance, yet its underlying mechanisms (how?) remain poorly understood. Questions also concern interindividual differences (who?), and the types of foods involved (what?). We hypothesized that negative affect would be linked to increased, and positive affect to decreased food approach bias (how?). These effects were expected to be moderated by trait EE (who?) and by the goal-congruency and hedonic value of the foods (what?). In 76 participants with self-regulatory, diet-related goals, we measured positive and negative affect using ecological momentary assessment, and approach bias toward goal-congruent and -incongruent foods using a mobile approach-avoidance task, on nine midday assessments. Hedonic food characteristics were assessed with food-specific craving ratings in the evening, and trait EE with the Salzburg Emotional Eating Scale. There was no direct association between affect and approach bias, nor one moderated by goal-congruency. Instead, affect and approach bias covaried on high-craving days: negative affect cooccurred with higher approach bias, while positive affect cooccurred with lower approach bias. These patterns were mainly present in participants reporting more intake during negative affect or less intake during positive affect (trait EE), respectively. Our results highlight temporally dynamic relationships between affect and approach bias as potential mechanisms of EE (how?) - although eating behavior itself was not studied here. Affect-bias links emerged on high-craving days (when?) in trait emotional eaters (who?) but irrespective of specific food characteristics (what?). This opens avenues for further mechanistic research and targeted eHealth interventions (when and in whom).