Bidirectional relationships between muscularity-oriented disordered eating and mental health constructs: a prospective study

Muscularity-oriented disordered eating (MODE) is a novel class of eating behaviors characterised by abnormal dietary alterations aimed towards building lean muscle. Although traditionally shown to affect men, emerging evidence suggests that increasingly more women are striving for the muscular and lean ideal, resulting in engagement of MODE behaviors. Prior research examining MODE in women is limited, yet emerging evidence from cross-sectional studies have established associations between MODE and poor mental health indices in this population. However, the temporal order of these associations in women is not yet known. Thus, the current study examined possible bi-directional associations between MODE behaviors and common mental health outcomes (depression, anxiety, loneliness). Adult women completed online study measures at baseline (Time 1 [T1]; n = 1760) and three-month follow-up (Time 2 [T2]; n = 1180). Cross-lagged panel models were computed to test for possible bi-directional relationships between MODE and the relevant mental health constructs. Findings showed that higher MODE levels at T1 significantly predicted increased depressive and anxiety symptoms (but not loneliness) at T2, and loneliness at T1 (but not depression/anxiety) significantly predicted MODE at T2. Effect sizes were small, so findings should be interpreted with this in mind. This is the first study to establish temporal relationships between MODE and mental health outcomes in adult women. Findings suggest that clinicians may benefit from inquiring about MODE behaviors for proper screening, assessment, and intervention, and potentially addressing loneliness to decrease risk of MODE.