The goal of this observational study is to learn if weight loss surgery can lower fat inside the heart muscle and improve how the heart relaxes in adults with obesity.

The main questions it aims to answer are:

Does fat inside the heart muscle decrease after weight loss surgery? Does heart relaxation (diastolic function) improve after surgery? Are changes in heart fat linked to changes in weight, body fat, and blood markers?

Participants who are already planning to have weight loss surgery will take part in this study.

Participants will:

Have a heart CT scan to measure fat in the heart muscle before surgery and about 6 months after surgery Have an ultrasound of the heart (echocardiogram) to check how the heart fills and relaxes Have body composition testing to measure fat and muscle Have blood tests, including routine tests and additional markers related to heart function and metabolism

Researchers will compare each participant's results before and after surgery to see if heart fat decreases and if heart function and blood markers improve.

Inclusion Criteria:

• Adults aged 18 years or older
• Scheduled to undergo bariatric surgery for standard clinical indications
• Left ventricular ejection fraction (LVEF) ≥50%
• Able to undergo cardiac computed tomography (CT)

Exclusion Criteria:

• Left ventricular ejection fraction (LVEF) <50%
• Known cardiomyopathies, including sarcoidosis, amyloidosis, or myocarditis
• Significant valvular heart disease
• Contraindication to cardiac CT (e.g., severe renal dysfunction, contrast allergy)
• Presence of intracardiac or cardiac-related foreign material that may interfere with imaging (e.g., prosthetic valves, pacemakers, prior transcatheter devices)

Adults with obesity who are scheduled to undergo bariatric surgery for standard clinical care at a tertiary medical center. Participants will be recruited during their preoperative evaluation and will undergo baseline and follow-up assessments, including cardiac imaging and clinical measurements, as part of the study.

Individual participant data (IPD) sharing is currently undecided. Any future data sharing will depend on institutional policies, ethical approvals, and applicable data protection regulations. If shared, only de-identified data will be made available to qualified researchers upon reasonable request.