Cognitive rigidity and restrictive eating disorders: Delineating the impact of low weight, low fat, weight suppression, acute negative energy balance, and chronic restriction.

Restrictive eating disorders such as anorexia nervosa (AN) are characterized by extremely rigid cognitive and behavioral patterns, understood to underpin the chronic nature of these disorders. Interrogating the mechanisms contributing to and maintaining the rigid cognitive styles and limited behavioral repertoires, particularly in terms of restrictive eating and excessive exercise is of critical importance. Dietary restriction is overall understood to underpin this rigidity to a large extent, however, to date little is understood regarding the relative contributions of different aspects of restriction including low body weight, low fat mass, weight suppression, acute negative energy balance, and chronic restriction. Clarifying the respective roles of these different factors would be useful for both the better targeting intervention efforts in AN. Extending research to other disorders such as muscle dysmorphia, avoidant restrictive food intake disorders, or atypical AN, that may present similar features to AN but differ from it on other critical dimensions, may offer unique opportunities to identify clinical elements specific to these cognitive patterns. Doing so may inform interventions and pave the way towards more effective treatment approaches.