Body Composition, Obesity, and Exercise

Obesity affects a large proportion of older adults, contributing to poor physical and mental health outcomes. Yet, weight loss (WL) interventions have been under-studied in this population due to concerns about exacerbating age-related reductions in muscle mass, bone density, and physical function. Thus, the potential influence of WL interventions on mental health and quality of life is mostly unknown. We assessed these attributes in a group of community-dwelling, obese (BMI ≥30 kg/m2) older adults (≥60 yr; n = 67) with mild to moderate physical impairment (SPPB score 4–10 out of 12) who were participating in a 6-month WL intervention (-500 kcal/day deficit; 2 diet groups [0.8 g versus 1.2 protein/kg body wt/day]). Significant weight loss and improved SPPB scores (ps < 0.05) were achieved by both groups. Mixed model analysis of the combined groups revealed short-term improvements in mental composite quality of life (SF-36), positive affect (CES-D), and total mood disturbance (POMS) at 3 months and sustained improvement of physical composite quality of life and its subdomains at both 3 and 6 months (ps < 0.05). Conversely, higher baseline depression (CES-D and POMS) and anger (POMS) and longer sleep latency (PSQI) were associated with less successful WL and blunted functional benefit. These findings demonstrate the potential benefits to mental health and quality of life of intentional WL in obese older adults and underscores the need for evaluation of mental health when considering a WL intervention for obese older adults.