Examining the effects of stress on eating behaviour in children and young adults.

In adults, stress has been found to initiate both increases and decreases in eating behaviours, and has been found to affect the types of foods consumed. However, there is a paucity of research on stress and eating amongst children and few studies have investigated the role of other factors such as positive and negative emotions. This thesis explored the impact that stress and emotions had on the eating behaviours of children aged 8-12 years in comparison to that of undergraduate students aged 18-49 years. To explore this, four studies were conducted, of which two utilised a repeated measures daily diary design where stress was also measured using salivary cortisol. Stress was measured by assessing daily hassles and emotions were measured by assessing positive and negative emotions together with daily uplifts. To explore eating behaviour, self-reported between-meal snacking was the main outcome variable. Overall, stress was found to be associated with the snacking behaviours of both children and undergraduate students (Studies 1 and 2). Children provided more snack responses for positive emotions, whereas undergraduate students responded more for negative emotions (Study 1). Total hassles were found to be positively related to total snack consumption. The impact of total hassles on total snack consumption was moderated by cortisol reactivity within children (Study 3). Amongst undergraduate students, the relationship between total hassles and unhealthy (high in sugar and fat) snack consumption was moderated by cortisol awakening response (Study 4). Future research should consider concerns of under/over-reporting snack behaviours and the difficulty of ensuring newly formed stress measures are valid. There are however additional individual factors (e.g., gender and ethnicity) that could influence the stress-eating relationship. It would be useful if researchers explored developing individual coping strategies to reduce the effects of stress and emotion on eating behaviours.