I hope this is not taken as a call to get obese. I am posting it simply as an example that obesity may be a protective mechanism once a disease is already established. As such, it should not be viewed always in a negative light but as a possible result of an endocrine disorder, which likely caused both the obesity and the AFib issue in the first place.
Obesity and Prognosis in Atrial Fibrillation - American College of Cardiology
"...Obesity is an independent predictor of new-onset AF and recurrent AF during antiarrhythmic drug treatment or after catheter ablation. Yet this and prior studies suggest that in patients with AF, adverse outcomes such as mortality are less likely in patients who are overweight or obese. This relationship between obesity and improved prognosis also has been reported in patients with hypertension, coronary artery disease, and heart failure. Because there is no clear-cut explanation for this counter-intuitive relationship, the term ‘obesity paradox’ is very appropriate."
Obesity and Prognosis in Atrial Fibrillation - American College of Cardiology
"...Obesity is an independent predictor of new-onset AF and recurrent AF during antiarrhythmic drug treatment or after catheter ablation. Yet this and prior studies suggest that in patients with AF, adverse outcomes such as mortality are less likely in patients who are overweight or obese. This relationship between obesity and improved prognosis also has been reported in patients with hypertension, coronary artery disease, and heart failure. Because there is no clear-cut explanation for this counter-intuitive relationship, the term ‘obesity paradox’ is very appropriate."