['Changes in body composition underlying the association between weight loss and higher mortality are not clear.', 'The objective was to investigate the association between changes in body composition of the appendicular (4 limbs) and central (trunk) compartments and all-cause mortality in men.', 'In men aged > or = 50 y, body composition was assessed every 18 mo for 7.5 y with a whole-body dual-energy X-ray absorptiometry scan. Mortality was assessed for 10 y. Data were analyzed by logistic regression and Cox model and adjusted for age, body mass index (BMI), educational level, lifestyle, physical performance, comorbidities, body composition, and serum concentrations of 17beta-estradiol and 25-hydroxycholecalciferol.', 'Of 715 men who were followed up, 137 (19.2%) died. Mortality was higher in men with the fastest weight loss [lowest compared with middle tertile odds ratio (OR): 2.31; 99% CI: 1.05, 5.09]. Faster loss of appendicular skeletal muscle mass (ASMM) was predictive of mortality (lowest compared with middle tertile OR: 3.60; 99% CI: 1.64, 7.89). Faster loss in ASMM remained a strong predictor of mortality after adjustment for weight loss (OR: 3.41; 99% CI: 1.51, 7.71). Faster loss in ASMM was the strongest predictor of death in the stepwise procedures when it was analyzed jointly with changes in the mass of other compartments. Loss in ASMM calculated over 36 mo was also a stronger predictor of death than were changes in the mass of other compartments (hazard ratio: 1.33 per 1-SD decrease; 95% CI: 1.06, 1.66).'] Is rapid loss of appendicular skeletal muscle mass associated with higher all-cause mortality in older men : the prospective MINOS study?