["European Eating Disorders Review, EarlyView. ", "\nABSTRACT\n\nObjective\nWhile loss of control (LOC) eating is associated with poor outcomes following metabolic and bariatric surgery (MBS), the mechanisms driving it are less understood. This study used momentary, naturalistic data to examine glucose as a biological correlate of LOC eating after Roux‐en‐Y gastric bypass (RYGB).\n\n\nMethod\nParticipants (45 adults one‐year post‐RYGB) completed 10 days of ecological momentary assessment (EMA) while wearing a continuous glucose monitor (CGM). Eating episodes reported in EMA were time‐matched to CGM readings 3 hours before and after eating episodes. Four CGM metrics (mean, variability, time in hyper‐ and hypo‐glycaemia) were used in multilevel models to test whether glucose functioning was a significant antecedent and/or consequence of LOC eating.\n\n\nResults\nGreater mean glucose levels and variability each significantly predicted engagement in an eating episode, while more time spent in hyperglycemia predicted the absence of eating. Significantly higher mean glucose was observed after eating. No glucose metric specifically predicted engagement in LOC eating; however, LOC eating resulted in significantly greater glucose variability.\n\n\nConclusions\nGlucose level and variability predicted subsequent eating, but not LOC eating. However, LOC eating was associated with subsequent glucose variability, which might help explain how LOC eating is associated with poorer outcomes following RYGB.\n\n"]