Exercise and Dietary Lifestyle Intervention on Reducing Atrial Fibrillation Burden, Cardiac and Body Fat Mass.

Inclusion Criteria: * Age 18-75 years * Body mass index (BMI) ≥27 kg/m² * Documented atrial fibrillation (paroxysmal or persistent) * Ability to participate in exercise training and follow study procedures * Access to a smartphone or device enabling rhythm monitoring * Provides written informed consent Exclusion Criteria: * Permanent atrial fibrillation * Unstable angina pectoris or acute coronary syndrome within the past 3 months * Participation in other lifestyle or drug weight reduction trials * Significant left ventricular dysfunction (ejection fraction \<30%) * Severe valvular heart disease or planned cardiac surgery * Severe heart failure (NYHA class IV) or severe angina (CCS class IV) * Unstable coronary artery disease or recent myocardial infarction * Severe pulmonary disease limiting exercise capacity * Active malignancy * Autoimmune or systemic inflammatory diseases * Severe renal or hepatic failure * Memory disease or significant cognitive impairment * Unstable psychiatric condition * Recent joint or back surgery within the past 6 months * Continuing back or joint pain symptoms and inability to take part in individualized exercise training * Contraindications to exercise testing or training, including cardiac symptoms or cardiovascular symptoms, making exercise unsafe * Pregnancy or breastfeeding * Participation in another interventional study * Any condition judged by investigators to make participation unsafe or infeasible