BackgroundObesity is a major concern in patients with bipolar disorder (BD) and problematic eating behaviors have been suggested to mediate their relationship. The association between problematic eating behaviors and obesity has been studied but limited data have explored the role of BD. We investigated problematic eating behaviors among patients with BD compared with candidates for bariatric surgery (BS), with or without BD, and explored the possible correlations between mood spectrum, impulsivity, body mass index (BMI). Methods50 euthymic patients with BD and 200 subjects eligible for BS, 48 with BD (BS + BD) and 152 without BD (BS-BD), were recruited at the Psychiatric Clinic of University of Pisa. Assessments included: Structured Clinical Interview (SCID-5), Emotional Eating Scale (EES), Yale Food Addiction Scale (YFAS), Eating Disorder Inventory (EDI-2), Eating Disorder Questionnaire (EDE-Q), Night Eating Scale (NES), Grazing Questionnaire (GQ), Mood Spectrum Self-Report (MOOD-SR), Barratt Impulsivity Scale (BIS). ResultsBS + BD reported significantly higher EDI-2 and EDE-Q scores than the other groups. BD and BS + BD showed significantly higher BIS-11 scores than BS-BD. Among BS, EES and YFAS were associated with mood spectrum symptoms. LimitationsSmall BD sample size, BS may have underreported psychiatric symptoms to get approved for surgery, the interview didn't inquire about BS receiving GLP-1 agonists therapy. ConclusionsResults showed a high prevalence of problematic eating behaviors among patients with BD and severely obese. Problematic eating behaviors may aggravate BD symptoms. Mood spectrum symptoms in obese subjects need to be carefully researched in as relate to severity and post-surgical course of BS.