Brain Correlates of Eating Disorders in Response to Food Visual Stimuli: A Systematic Narrative Review of FMRI Studies

Abstract

This article summarizes the results of studies in which functional magnetic resonance imaging (fMRI) was performed to investigate the neurofunctional activations involved in processing visual stimuli from food in individuals with anorexia nervosa (AN), bulimia nervosa (BN) and binge eating disorder (BED). A systematic review approach based on the PRISMA guidelines was used. Three databases—Scopus, PubMed and Web of Science (WoS)—were searched for brain correlates of each eating disorder. From an original pool of 688 articles, 30 articles were included and discussed. The selected studies did not always overlap in terms of research design and observed outcomes, but it was possible to identify some regularities that characterized each eating disorder. As if there were two complementary regulatory strategies, AN seems to be associated with general hyperactivity in brain regions involved in top-down control and emotional areas, such as the amygdala, insula and hypothalamus. The insula and striatum are hyperactive in BN patients and likely involved in abnormalities of impulsivity and emotion regulation. Finally, the temporal cortex and striatum appear to be involved in the neural correlates of BED, linking this condition to use of dissociative strategies and addictive aspects. Although further studies are needed, this review shows that there are specific activation pathways. Therefore, it is necessary to pay special attention to triggers, targets and maintenance processes in order to plan effective therapeutic interventions. Clinical implications are discussed.

Sensory processing across eating disorders: A systematic review and meta‐analysis of self‐report inventories

“…Indeed, all exteroceptive modalities, and particularly smell and taste, have been correlated with food selectivity, that is, limited variety of foods, and feeding problems, that is, problems with the introduction/transition of textures (Campos‐Sanchez et al, 2024; Farrow & Coulthard, 2012). In adults, studies investigating neural correlates of sensory processing using methods such as magnetic resonance imaging in relation to disordered eating have yielded inconsistent results due to the heterogeneity in research designs and the use of different task types to elicit a brain response to stimuli (Celeghin et al, 2023; Klabunde et al, 2017; Simon et al, 2019). Similarly, studies using heartbeat monitoring tasks to assess cardioception have yielded inconsistent results, with some studies finding no differences between EDs and HC (see Kinnaird et al, 2020) while others have found that EDs were associated with significantly altered cardioception compared to HC (see Pollatos et al, 2008).…”

Neuronal activity and reward processing in relation to binge eating

“…Data associating binge-eating behavior to brain regions of the reward circuit are growing in the literature and already summarized in several recently published reviews [11][12][13]. These reviews mainly focus on the association between disturbed eating behavior and/or binge eating with specific brain reward pathways but do not take valid subconstructs of reward processing into account [1 && ].…”

“…This is in line with structural data, finding higher volumes in cortical areas, as well as NAc [18 & ,19 & ]. Interestingly, patients with bulimia nervosa may have even higher OFC volume and activation of ACC during food anticipation compared with BED [11,20].…”

Linking drug and food addiction: an overview of the shared neural circuits and behavioral phenotype

“…In human studies, subjects with BED and bulimia nervosa show weakened functional connectivity between the left lateral OFC, which is implicated in the inhibitory suppression of rewarded choices ( Mar et al, 2011 ; Gourley et al, 2016 ) and the right dorsolateral PFC (DLPFC) ( Ahn et al, 2022 ), which mediates the relationship between motor urgency and response inhibition ( Hu et al, 2016 ). When exposed to high-calorie food stimuli, individuals with BED display an overactivation of the OFC ( Schienle et al, 2009 ; Hone-Blanchet and Fecteau, 2014 ; Meng et al, 2020 ; Celeghin et al, 2023 ). Notably, lateral OFC is crucial for goal-directed behavior.…”