Stress And Eating Behaviours In Healthy Adults: A Systematic Review And Meta-Analysis

Stress leads to detrimental health outcomes through direct biological and indirect behavioural changes. Stress can lead to disruption to normal eating behaviours, although the strength of these associations is unknown. This is the first meta-analysis to determine the strength of the stress-eating relationship in healthy adults and to explore the impact of potential moderators. Studies included had a clearly defined measure of stress (i.e., any noxious event or episode in one’s environment with the exclusion of emotional distress) that was linked to non-disordered eating. Key terms were searched in Medline, PsycInfo and Ovid databases (23,104 studies identified). 54 studies (combined N = 119,820) were retained in the meta-analysis. A small, positive effect size was found for the stress-overall food intake relationship (Hedges’ g = 0.114). Stress was associated with increased consumption of unhealthy foods (Hedges’ g = 0.116) but decreased consumption of healthy foods (Hedges’ g = -0.111). Only one significant moderator (restraint on stress-unhealthy eating) was identified. This meta-analysis identified the magnitude of the effect of stress on eating behaviour outcomes. Significant heterogeneity was observed that was not explained by the moderators examined. Further research on moderators of the stress-eating relationship is required and should distinguish effects for healthy versus unhealthy eating

Ghrelin plays a role in various physiological and pathophysiological brain functions

The ghrelin receptor is now known to play an important role in regulating physiological responses to stress. In particular, ghrelin acting at the growth hormone secretagogue receptor (ghrelin receptor) may promote anxious behaviours under non-stressed conditions, and attenuate anxiety under conditions of stress. Dysregulation of the ghrelin system therefore has significant consequences for stress-related mood disorders such as anxiety and depression; disorders that pose a substantial problem for human health. These effects of the ghrelin system on mood are of particular concern in obese populations, where the likelihood of a mood disorder is higher and the ghrelin system disrupted. Studies in humans are still revealing conflicting roles for ghrelin and the ghrelin receptor in anxiety and depression, but these, and studies in animal models, offer evidence that ghrelin may influence its receptor at extra-hypothalamic brain regions to exert indirect control over central responses to stress and over brain pathways related to anxiety and depression. In this chapter, I discuss the background and potential mechanisms for ghrelin and ghrelin receptor's role in regulating stress and stress-related mood disorders