Background Obesity is a risk factor for frailty and muscle weakness, so weight loss in obese older adults may prevent frailty and functional decline. Objective To assess the safety and efficacy of a multimodal weight-loss intervention in improving functional performance and reducing frailty risk in obese older adults. Design Randomized controlled trial with 2 parallel arms. SETTING AND PARTICIPANTS: Community-dwelling obese adults aged 65–75 years with body mass index (BMI) 30–39 kg/m 2 . INTERVENTION: 6-month multimodal intervention based on diet and a physical activity program. Control group: Usual care. Main and Secondary Outcome Measures Frailty (Fried criteria) rate and functional performance at 6, 12, and 24 months of follow-up, respectively. Intermediate Outcome Measures Weight loss, body composition changes, and metabolic and inflammatory biomarker changes. Results N=305. The study intervention increased gait speed at 12 and 24 months of follow-up, but had no significant effect on frailty prevention. It was effective in reducing weight, BMI, fat mass, interleukin 6, and insulin resistance and improving self-reported quality of life. Conclusions The study intervention was not demonstrated to be effective in preventing frailty in obese people aged 65–75 years at 24 months of follow-up. However, it allowed weight loss and a reduction in inflammatory and insulin resistance markers, which could have a long-term effect on frailty that requires further research.

BackgroundAs a person ages, total body water (TBW), intracellular water (ICW), muscle mass and muscle strength tend to decline. The decline in ICW may reflect losses in the number of muscle cells but may also be responsible for less hydrated muscle cells.AimTo assess whether TBW and ICW are associated with muscle strength, functional performance and frailty in an aged population, independently of muscle mass.Methodology: DesignAn observational cross-sectional study of community-dwelling individuals aged 75 years and older. TBW, ICW, fat mass, lean mass and muscle mass were assessed by bioelectrical impedance analysis, frailty status was measured according to Fried criteria, handgrip strength was measured using the hand-held JAMAR dynamometer, and functional performance was measured according to the Barthel index and gait speed.ResultsA total of 324 subjects were recruited (mean age 80.1 years, 47.5% women). TBW and ICW were closely correlated with muscle mass in both sexes. ICW was also associated with Barthel score, gait speed and frailty in both sexes and with handgrip in men. Considerable variability in ICW was observed for the same muscle mass. Multivariate analysis showed a positive effect of ICW on handgrip, functional performance and gait speed and a protective effect of ICW on frailty, independently of age, sex, body mass index and number of comorbidities.ConclusionsIn elderly individuals with similar muscle mass, those with higher ICW had a better functional performance and a lower frailty risk, suggesting a protective effect of cell hydration, independently of muscle mass.