Purpose of review Obesity, a growing global health problem, contributes to the development of heart failure. However, increased BMI seems protective for those with established disease, a phenomenon known as the 'obesity paradox'. In this review, we outline the mechanism through which obesity can contribute to the development of heart failure, explore the concept of obesity paradox, and highlight the challenges that obesity presents for advanced heart failure therapy. Recent findings Although the mechanism underlying the obesity paradox is complex, meta-analysis shows that intentional weight loss through bariatric surgery can indeed improve cardiac structure and function. With regard to ventricular assist device therapy in obese patients, recent studies demonstrate that while obesity was indeed associated with higher likelihood of complications, there were no statistically significant differences in terms of mortality or delisting from cardiac transplant waiting list. Summary Obesity is strongly associated with the development of heart failure, through direct and indirect mechanisms. Although clear consensus regarding weight reduction in this patient population is lacking, there is mounting clinical evidence that intentional weight loss may be beneficial, in spite of the well-recognized obesity paradox, particularly as the presence of obesity presents unique challenges in the advanced therapy of heart failure patients.