Thomas E, et al. - Researchers investigated whether body composition analysis may reveal that muscle mass rather than adipose tissue accounts for the obesity paradox. To that end, they used an In Body 520 body composition scale and performed a bioelectrical impedance analysis of body composition in 359 outpatients with heart failure (HF). Body fat and lean mass were indexed by height (m²). Participants had a mean age of 56 ± 14 years, mean left ventricular ejection fraction was 38% ± 16%, and were stratified by median fat and lean mass indexed by height. Findings revealed greatly improved 5-year survival among patients with higher indexed body fat mass vs patients with lower indexed body fat mass (90.2% vs 80.1%). Also, improved survival was observed in patients with high vs low indexed lean body mass (89.3% vs 80.9%). The combination of low lean with low-fat mass was found to be independently related to poor prognosis. Overall, in HF, improved outcomes were observed in association with higher fat mass and, to a lesser extent, higher lean mass.