The neurobiology of binge eating disorder: a systematic review of studies using functional magnetic resonance imaging.

Binge eating disorder (BED) is a prevalent public health concern associated with significant medical and psychosocial burden. To better understand the mechanisms underlying this concern, the present systematic review aimed to synthesize findings from resting-state and task-based functional magnetic resonance imaging (fMRI) studies of the neurobiology of BED. PubMed, MEDLINE, PsycInfo, Embase, and Web of Science were searched, the Joanna Briggs Institute Critical Appraisal Tools were used, and the PRISMA guidelines were followed. The review identified 24 studies, comprising approximately 1,689 non-independent participants from an estimated 17 unique cohorts. These included task-based fMRI studies (n = 14), resting-state fMRI studies (n = 6), and BED treatment-outcome fMRI studies (n = 4). Key findings of the review included: (i) differences in neural responsivity to palatable food cues involving reward- and salience-related circuitry (e.g., orbitofrontal cortex, ventral striatum, and insula), alongside reduced recruitment of inhibitory-control regions during cognitive-control tasks; (ii) evidence suggesting reward-related differences in BED may be more food-specific than generalized across reward types, although some findings indicate broader frontostriatal hyporesponsivity during monetary reward processing; and, (iii) findings indicating that BED may share neurobiological overlap with, but remain distinguishable from, obesity and bulimia nervosa. However, these findings/interpretations are preliminary, given limitations in the current evidence base, including small samples, methodological heterogeneity, and the underrepresentation of males. Future neuroimaging studies should prioritize large-scale, longitudinal, efforts that include more representative (e.g., greater inclusion of males) and developmental (e.g., more children and adolescents) samples and consider socioenvironmental contexts relevant to BED. Such efforts may help inform individual-level personalized interventions.