Obesity paradox, cachexia, frailty, and heart failure.

Overweight and obesity adversely affect cardiovascular (CV) risk factors and CV structure and function, and lead to a marked increase in the risk of developing heart failure (HF). Despite this, an obesity paradox exists, wherein those who are overweight and obese with HF have a better prognosis than their leaner counterparts, and the underweight, frail, and cachectic have a particularly poor prognosis. In light of this, the potential benefits of exercise training and efforts to improve cardiorespiratory fitness, as well as the potential for weight reduction, especially in severely obese patients with HF, are discussed.