Obesity as a chronic illness of the 21st century is not just an aesthetic problem but also a health disorder. Due to its great influence on the cardiovascular system, it has drawn attention of many scientists. The number of cardiovascular patients is increasing every day because of a sedentary lifestyle. Atrial fibrillation is the most frequent type of cardiac rhythm disorder today and more and more people suffer from it. Many scientists have been trying to link these two diseases. The results of most studies show a positive correlation of obesity and it’s pathophysiological processes with the formation of atrial fibrillation and its complications. Nonetheless, some clinical studies show contradictory results. In order to test this thesis, the patients treated at the Clinic for heart and blood vessel disease at the University Hospital Rebro underwent “Structured weight loss program”. 79 obese patients participated in our study. The results of the research show that the “Structured weight loss program” reduces cardiometabolic risk and therefore also insulin resistance and inflammatory processes in the body, believed to be the trigger for atrial fibrillation. Our research has contributed to the overall understanding of the antiarrhythmic effect of weight reduction.