People who exhibit disordered eating behaviours, such as binge eating, restricting, and purging, are at increased risk of problematic alcohol use. It is commonly proposed that this is a partially causal relationship, with behaviours such as binging and restricting actively contributing to the development of problematic alcohol use. This may be because disordered eating behaviours can increase negative affect, reward sensitivity, and impulsivity, which are factors known to contribute to problematic alcohol use.

However, there are also reasons to believe that problematic alcohol use may in turn contribute to the development and maintenance of disordered eating behaviours, through similar mechanisms operating in the opposite direction. Additionally, ‘out of control’ or ‘binge-type’ alcohol use may be particularly distressing for individuals with disordered eating, due to the caloric nature of alcohol, and thus may result in increased compensatory behaviours (i.e., disordered eating behaviours). Longitudinal studies thus far have reported mixed findings regarding the causal direction between disordered eating behaviours and problematic alcohol use and have been hampered either by small sample sizes or poor measures.

Thus, this project aims to investigate and describe the direction(s) of causation between disordered eating behaviours and problematic alcohol use using robust measures and a large sample size.

Furthermore, the literature is unclear on whether purging or bingeing is more related to problematic alcohol use, as many studies have either looked at one or the other, or collapsed them into one category (i.e., ‘bulimic symptoms’). Thus, this study will look to consider the relative magnitude of association of each of these two behaviours, as well as restrictive eating behaviours, and problematic alcohol use.