Sex difference in neural substrates linking negative body image and disordered eating behaviors.

Based on the dual-pathway model, negative body image concerning body weight/shape has been widely recognized as a critical risk factor influencing disordered eating behaviors. Despite progress in behavioral mechanisms regarding the relationship, the neural mechanisms remain unknown. Moreover, sex difference should be considered due to its salient role in neural representations underpinning negative body image. To address these issues, this study employed resting state fMRI technique to examine the sex differences in functional connectivity (FC) characteristics underlying negative body image in a relatively large sample, and further revealed the association between FCs and disordered eating behaviors in different sexes. Results indicated that the interaction between negative body image and sex was observed in FCs between frontoparietal network, memory retrieval network, default mode network, sensorimotor network, and visual and subcortical areas. Furthermore, the FC between superior frontal gyrus in default mode network and medial superior frontal gyrus in frontoparietal network was associated with binge eating through the mediating role of restrained eating. Current work provides novel insights into the neural mechanisms underlying the association between negative body image and disordered eating behaviors. These neural findings also offer theoretical evidence for developing preventions and interventions targeting related mental disorders.