Does the Type of Stressor Moderate the Stress-Snacking Relationship? An Intensive-Longitudinal Study.

Objective: Stress can influence health via changes in health behavior, such as unhealthy snacking. However, previous research on this relationship is inconsistent, indicating between- or within-person differences. We examined the type of stressor as a contextual moderator in the stress-unhealthy snacking relationship in everyday life. We further differentiated perceived stress and the physiological stress response.

Methods: Students, a population at risk of stress and unhealthy snacking (N=66, 1'989 observations), participated in a 4-day intensive longitudinal study. Perceived stress and unhealthy snacks consumed were recorded eight times daily. Heart rate variability (HRV), an indicator of the physiological stress response, was measured continuously using a validated ambulatory electrocardiogram sensor (ecgMove 4). Lower HRV indicates greater physiological stress. Data were analyzed using generalized estimating equations.

Results: No relationship was found between general stress and unhealthy snacking, but the type of stressor moderated this association. When reporting a work-related stressor as opposed to other stressors, individuals subsequently (i.e., during the next two hours) consumed fewer unhealthy snacks as momentary perceived stress increased. When reporting an interpersonal stressor, individuals consumed more unhealthy snacks as momentary HRV increased. Individuals who typically perceived more stress ate more and those with typically higher HRV ate fewer unhealthy snacks when experiencing an interpersonal stressor.

Conclusion: The results shed light on the complex relationship between stress and eating. Considering the type of stressor, distinguishing perceived stress and the physiological stress response, and within- and between-person differences is important for understanding the relationship between stress and unhealthy snacking in everyday life.