Interoception and Illness Perception Before and After Bariatric Surgery: Impact on Disordered Eating (Interoceptiv-BAR)

Interoception and Illness Perception Before and After Bariatric Surgery: Impact on Disordered Eating Behaviors

Obesity is associated with alterations in the perception and interpretation of internal bodily signals (interoception), which may influence eating behaviors, emotional regulation, and long-term weight outcomes. Bariatric surgery induces profound physiological and neurohormonal changes that may affect interoceptive awareness and illness perception, potentially impacting the risk of disordered eating behaviors after surgery.

This observational study aims to evaluate longitudinal changes in interoceptive awareness and illness perception in adults with severe obesity undergoing bariatric surgery, from the pre-operative phase to long-term follow-up. The study also explores the relationship between these psychological constructs and clinical and behavioral outcomes over time.

Study Overview

• Status: Recruiting
• Conditions: Obesity

Detailed Description

Interoception refers to the ability to perceive, interpret, and integrate internal bodily signals and plays a key role in appetite regulation, emotional processing, and eating behavior. Altered interoceptive processing has been associated with obesity, disordered eating behaviors, and psychological distress. In individuals with severe obesity, bariatric surgery represents the most effective treatment for weight reduction; however, the persistence or recurrence of maladaptive eating behaviors after surgery remains a relevant clinical concern.

Bariatric surgery leads to marked modifications in the gut-brain axis, neuroendocrine signaling, and central processing of internal bodily signals. These changes may influence interoceptive awareness and illness perception, which in turn could affect long-term behavioral, psychological, and clinical outcomes. Despite increasing interest in these mechanisms, longitudinal evidence on subjective interoceptive changes and illness perception before and after bariatric surgery remains limited.

This monocentric, longitudinal, ambispective observational study is conducted in adults with severe obesity evaluated for bariatric surgery at a tertiary referral center. Psychological and clinical data are collected during the pre-operative assessment and during post-surgical follow-up, allowing the evaluation of changes over time in interoceptive awareness, illness perception, psychological functioning, and weight-related outcomes.

The study includes both a retrospective component, based on existing clinical data, and a prospective component with repeated assessments over long-term follow-up. By characterizing trajectories of interoceptive awareness and illness perception before and after bariatric surgery, this study aims to improve the understanding of psychological and behavioral factors involved in post-surgical outcomes and to support the development of more personalized multidisciplinary care pathways for patients with severe obesity.

• Study Type: Observational
• Enrollment (Estimated): 300

Contacts and Locations

• Study Contact: Name: Maria Rosaria Magurano, PC; Phone Number: +393663940248; Email: mariarosaria.magurano@policlinicogemelli.it

Study Locations

• Italy
  • Lazio
    • Rome, Lazio, Italy, 00168
      • Recruiting
      • Fondazione Policlinico Universitario A. Gemelli IRCCS
      • Contact: Maria Rosaria Magurano, PC; Phone Number: +393663940248; Email: mariarosaria.magurano@policlinicogemelli.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adults with severe or morbid obesity undergoing pre-operative multidisciplinary evaluation for bariatric surgery at a tertiary referral center. Participants are assessed before surgery and during post-surgical follow-up as part of routine clinical care.

Description

Inclusion Criteria:

• Adults aged 18 years or older.
• Diagnosis of severe or morbid obesity (body mass index ≥35 kg/m² with obesity-related comorbidities or ≥40 kg/m²).
• Undergoing multidisciplinary evaluation with indication for bariatric surgery.
• Ability to provide informed consent and complete self-administered questionnaires.

Exclusion Criteria:

• Age younger than 18 years.
• Presence of neurological disorders associated with cognitive impairment that may interfere with questionnaire completion.
• Pregnancy or breastfeeding at the time of enrollment.
• Inability to complete study assessments due to language barriers or other conditions limiting participation.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in interoceptive awareness measured by the Multidimensional Assessment of Interoceptive Awareness (MAIA)	Change from baseline to 24 months in MAIA subscale scores. The MAIA is a validated 32-item self-report questionnaire assessing interoceptive awareness across 8 dimensions. Each item is rated on a Likert scale, and subscale scores are calculated as the mean of corresponding items. Higher scores indicate greater interoceptive awareness.	Baseline to 24 months after bariatric surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in illness perception measured by the Illness Perception Questionnaire-Revised (IPQ-R)	Change from baseline to 24 months in cognitive and emotional domains of the IPQ-R. The IPQ-R includes multiple domains assessing illness representations using Likert scales. Higher scores indicate stronger endorsement of the measured dimension (interpretation depends on domain).	Baseline to 24 months after bariatric surgery
Anthropometrics	Change in body weight from baseline to 12 and 24 months after bariatric surgery.	Baseline, 12 months, and 24 months after bariatric surgery
Changes in Depression	Change in depressive symptoms assessed by the Patient Health Questionnaire-9 (PHQ-9)from baseline to follow-up.	Baseline, 12 months, and 24 months after bariatric surgery
Changes in Disordered Eating Behaviors	Change in disordered eating behaviors assessed by the Eating Disorder Examination Questionnaire 6.0 (EDE-Q6)	Baseline, 12 months, and 24 months after bariatric surgery
Changes in Psychological Functioning	Change in general psychological functioning assessed by the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM).	Baseline, 12 months, and 24 months after bariatric surgery
Changes in Health-Related Quality of Life	Change in health-related quality of life assessed by the Short Form-36 Health Survey (SF-36).	Baseline, 12 months, and 24 months after bariatric surgery
Anthropometrics	Change in body mass index (BMI) from baseline to 12 and 24 months after bariatric surgery.	Time frame: baseline, 12, 24 months
Changes Anxiety Symptoms	Change in depressive symptoms assessed by the anxiety symptoms assessed by the Generalized Anxiety Disorder-7 (GAD-7) from baseline to follow-up.	Baseline, 12 months, and 24 months after bariatric surgery
Changes in Disordered Eating Behaviors 1	Change in disordered eating behaviors assessed by the Binge Eating Scale (BES).	Baseline, 12 months, and 24 months after bariatric surgery
Changes in Disordered Eating Behaviors 2	Change in disordered eating behaviors assessed by the Clinical Impairment Assessment (CIA).	Baseline, 12 months, and 24 months after bariatric surgery

Collaborators and Investigators

• Sponsor: Fondazione Policlinico Universitario Agostino Gemelli IRCCS
• Investigators: Principal Investigator: Maria Rosaria Magurano, Fondazione Policlinico A. Gemelli IRCCS

Study record dates

Study Major Dates

• Study Start (Actual): May 13, 2026
• Primary Completion (Estimated): May 13, 2027
• Study Completion (Estimated): May 13, 2028

Study Registration Dates

• First Submitted: May 7, 2026
• First Submitted That Met QC Criteria: May 14, 2026
• First Posted (Actual): May 18, 2026

Study Record Updates

• Last Update Posted (Actual): September 3, 2026
• Last Update Submitted That Met QC Criteria: September 2, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Bariatric Surgery; Intetoception
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity
• Other Study ID Numbers: ID 27168 - Interoceptiv-BAR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No