BACKGROUND: Atrial fibrillation (AF) is a prevalent cardiac arrhythmia with significant health consequences. Identifying modifiable risk factors, such as obesity, is crucial. While body mass index (BMI) is linked to increased AF risk, the association between new-onset AF (NOAF) and other anthropometric measures like waist circumference (WC) and body surface area (BSA) warrants further investigation. OBJECTIVES: This systematic review and meta-analysis aimed to compare mean WC and BSA between individuals who developed NOAF and those who did not. METHODS: We conducted a comprehensive search up to February 2024 for studies comparing mean WC and BSA in groups with and without incident NOAF. Participants had no prior AF history. We used a random-effects model to calculate standardized mean differences (SMDs) and 95 % confidence intervals (CIs). Subgroup analyses explored NOAF occurrence following coronary artery bypass graft (CABG) surgery, in the absence of any preceding procedure, and after other cardiac procedures. RESULTS: Our analysis of 34 studies revealed that adults with NOAF had significantly higher WC (SMD = 0.20, 95 % CI 0.01
0.39) and BSA (SMD = 0.06, 95 % CI 0.01
0.11) compared to those without NOAF. Subgroup analysis showed a more pronounced association in individuals developing NOAF after CABG (SMD = 0.33, 95 % CI 0.17
0.48) and in those without any prior procedure before NOAF diagnosis (SMD = 0.23, 95 % CI 0.08
0.38) versus those without NOAF. CONCLUSION: Higher WC and BSA appear to be significantly associated with an increased risk of NOAF, with the relations being more pronounced in specific subgroups.