The effects of negative and positive mood induction on eating behaviour: A meta-analysis of laboratory studies in the healthy population and eating and weight disorders

Objective: The aim of this study was to conduct a meta-analysis to quantify the effect of induced negative and positive mood on meal consumption in healthy participants and patients with eating and weight disorders. Method: The search term "MOOD" was combined with the following keywords: "TEST MEAL" or "LABORATORY FEEDING" or "LABORATORY MEAL" or "TASTE TEST" or "TASTE TASK" to identify the relevant studies. Results: Thirty-three studies were selected, including 2491 participants. Two meta-analyses compared negative mood or positive mood with neutral mood. Induced negative mood was significantly associated with greater food intake, especially in restrained eaters and binge eaters. Positive mood was also associated with greater caloric intake across groups. Conclusion: These findings support the causal relationship between negative mood and greater food intake, especially in restrained eaters and binge eaters. Preliminary evidence indicates that strategies to improve positive mood might be of benefit for people with anorexia nervosa and bulimia nervosa, although the size of the effect across a single meal is small.