Atrial fibrillation, the most common sustained arrhythmia encountered in clinical practice, is now considered a preventable disorder. Professional societies and the National Institutes of Health have highlighted the importance of addressing lifestyle factors as a pillar in the management of atrial fibrillation. Central among these is weight loss in individuals with overweight (body mass index [BMI, calculated as weight in kilograms divided by height in meters squared] between ≥27 and <30) and obesity (BMI ≥30), which now garners a class 1 recommendation in both US and European guidelines to reduce the risk of atrial fibrillation. The evidence supporting those recommendations is extensive.