Understanding moderating factors of stress-induced eating behaviours in emerging adulthood

This thesis aimed to investigate stress-induced eating behaviours across emerging adulthood and identify moderating variables on this relationship. Firstly, the findings of two meta-analyses highlighted that stress is associated with changes in the amount, and type, of foods consumed in adults and adolescents. The meta-analyses identified gaps in the literature including limited research using samples of adolescents and a paucity of objective measures of stress. A daily diary study was conducted to determine stress-eating associations in adolescents (N = 78) and young adults (N = 98). Results identified that daily stress was associated with increased consumption of between-meal snacks but was not associated with a change in healthy food consumption. Conscientiousness moderated stress-eating associations in young adults, where stress-eating associations were greatest in individuals high in conscientiousness compared to lower levels of this personality trait. Secondly, an experimental study combined objective (saliva and hair cortisol) and subjective measures of stress to determine the role of cortisol reactivity (to a stress-induction task) on daily stress-eating associations. In a sample of 123 participants (59 adolescents and 64 young adults), the study found that days with low levels of stress were associated with significant differences in total snacks consumed across AUC (i.e., cortisol reactivity) groups. However, on high stress days, there were no differences in total snack intake across the AUC groups. Chronically occurring stress (measured via hair sampling) was not associated with changes to stress-related eating habits across emerging adulthood. Eating style and emotion regulation differentially influenced stress-eating associations between adolescents and young adults.Combined with previous research, the findings of this thesis indicate that stress-eating associations are present in adolescents and may continue into adulthood. Moderating variables (such as cortisol reactivity, conscientiousness and eating style) should be considered in future research to understand the complex associations between stress and health.