Exploring the longitudinal association between stress and unhealthy eating behaviors: The role of physical activity, BMI, and loneliness

Previous cross-sectional research indicates a link between stress and unhealthy eating, but the longitudinal association remains unknown. This study examined the longitudinal association between perceived stress over a longer time period and unhealthy eating (i.e., sweet and savory snack intake, uncontrolled eating) in a student population. Moreover, we examined whether physical activity buffers such association, and examined whether this buffering effect is stronger for individuals with higher Body Mass Index (BMI) or greater loneliness. Two timepoints of online survey data (Time 1 Oct-Nov 2021, Time 2 May-July 2022) of Dutch university students (n = 1325, 74.7 % female, mean age 22.45 (SD = 2.31)) were used. Results revealed no longitudinal link between stress and snack intake in the total sample, but this association was found in a subgroup of individuals with a higher BMI. Stress at Time 1 was associated with later uncontrolled eating. Physical activity did not moderate the link between stress and unhealthy eating. However, we found a negative longitudinal link between physical activity and uncontrolled eating among individuals with a higher BMI. Our findings suggest that stress does not play an important role in explaining snack intake in university students, but may be associated with uncontrolled eating. Physical activity seems to be linked with a reduction in uncontrolled eating among individuals with a higher BMI specifically. Replication and extension of current findings in a more diverse (e.g., eating disordered) sample would increase insights into the (combined) effects of stress, BMI and physical activity on uncontrolled eating.