Associations between fear of weight gain and exercise in binge-spectrum eating disorders

Purpose: Maladaptive exercise (i.e., exercise that is either driven or compensatory) is thought to momentarily down-regulate elevated fear of weight gain (FOWG). However, little research has examined associations between FOWG and exercise, and no research has measured FOWG at a momentary level or considered exercise type (i.e., maladaptive vs. adaptive). Thus, we examined both within- and between-subject associations between FOWG and exercise among individuals with trans-diagnostic binge eating.

Methods: We recruited treatment-seeking adults (N = 58, 82.9% female) to complete a 7-14-day ecological momentary assessment protocol which assessed levels of FOWG and exercise engagement and type. Mixed models and generalized estimating equations assessed within-subject associations, and linear regression assessed between-subject associations.

Results: There was no main effect of FOWG on exercise engagement at the next survey. However, unexpectedly, exercise type moderated this relationship such that the relationship between FOWG and exercise was strongest for episodes of adaptive exercise. Overall exercise frequency accounted for 10.4% of the variance in FOWG and exercise type explained an additional 1.7% of the variance in FOWG.

Conclusion: The findings of the current study indicate that momentary levels of FOWG are associated with subsequent adaptive exercise episodes, while higher overall levels of maladaptive exercise were associated with higher levels of FOWG. Future treatments should place a greater emphasis on reducing the frequency of maladaptive exercise by providing strategies for reducing FOWG.

Level of evidence: Level IV: Evidence obtained from multiple time series analysis such as case studies.