Morbid exercise behaviour and eating disorders: A meta-analysis

Background and aims: This study examined the relationship between self-reported symptoms of morbid exercise behaviour (MEB) and eating disorders (ED) using meta-analytic techniques. Methods: We systematically searched MEDLINE, PsycINFO, Web of Science, SciELO and Scopus. Random effects models were used to compute pooled effect sizes estimates (r). The robustness of the summarized estimates was examined through sensitivity analyses by removing studies one at a time. Results: Sixty-six studies comprising 135 effect-sizes (N = 21,816) were included. The results revealed: (a) small-sized relationship in the case of bulimic symptoms (r = 0.19), (b) small- (r = 0.28) to medium-sized relationships (r = 0.41) in the case of body/eating concerns, and (c) medium-sized relationships in the case of overall ED symptoms (r = 0.35) and dietary restraint (r = 0.42). Larger effect sizes were observed in the case of overall ED symptoms in clinical, younger, and thinner populations, as well as when employing a continuously-scored instrument for assessing ED or the Compulsive Exercise Test for assessing MEB. Larger effect sizes were also found in female samples when the ED outcome was dietary restraint. Conclusions: The identified gaps in the literature suggest that future research on the topic may benefit from: (a) considering a range of clinical (in terms of diagnosed ED) and non-clinical populations from diverse exercise modalities, (b) addressing a wide range of ED symptomatology, and (c) employing longitudinal designs that clarify the temporal direction of the relationship under consideration.