Exploring the effects of daily hassles and uplifts on eating behaviour in young adults: The role of daily cortisol levels.

Existing stress-eating research has shown that daily hassles are associated with increases in food intake and that cortisol reactivity to stress has been found to influence the stress-eating relationship. However, the moderating effects of daily cortisol levels (e.g., the cortisol awakening response, CAR) remain unknown. Moreover, recent evidence has shown that daily uplifts, as well as daily hassles, are important in understanding daily influences on eating behaviour. Therefore, in the same study, the current investigation explored the effects of daily hassles and uplifts on eating behaviour and whether these relationships were moderated by mean daily cortisol levels in young female adults. Forty-nine female participants (M age: 19.13 years) recorded the daily hassles and uplifts that they experienced over a 4-day period, together with the between-meal snacks they consumed each day, using an online daily diary. Cortisol samples were provided daily immediately upon waking, at +30 min and +12 h. Mean CAR and mean cortisol levels were calculated across the 4 days. Using multi-level modeling, daily hassles and uplifts were both significantly associated with greater unhealthy snacking. Daily uplifts, but not daily hassles, were also associated with lower healthy snack intake. Higher levels of mean CAR were associated with lower daily healthy snack intake. Moreover, the effects of daily uplifts on healthy snacking were found to be moderated by mean daily cortisol levels, such that participants with the highest levels of mean cortisol consumed less healthy snacks on days when they experienced uplifts. The current study provides novel evidence that mean daily cortisol levels, as well as daily hassles and uplifts, are implicated in daily snack consumption in young female adults. The role of hypothalamic-pituitary adrenal axis activity should be explored further in the context of the daily hassles/uplifts and eating behaviours relationship, in men and in individuals from lower socio-economic status and minority groups.