The impact of lifestyle-based weight loss in older adults with obesity on muscle and bone health: a balancing act.

Despite adverse metabolic and functional consequences of obesity (BMI ≥30 kg/m²), clinical recommendations for weight loss (WL) in older adults (65+ years) with obesity remain controversial. Reluctance stems partly from epidemiologic data demonstrating musculoskeletal tissue loss with WL and increased risk of disability and osteoporotic fracture. Randomized controlled trials in older adults complement and extend knowledge in this area showing: (1) lifestyle-based WL interventions often yield clinically meaningful (~8%-10%) WL in older adults; (2) lean mass loss is significant, although fat mass loss is preferential and physical performance is often improved, particularly when combined with aerobic and resistance training (RT); (3) bone loss is also significant, with some evidence that RT can attenuate WL-associated bone loss; and (4) fat mass regain after intervention cessation is common, yet physical performance gains appear to be maintained. Best practices for treating older adults with obesity include comprehensive assessment of baseline musculoskeletal health; patient-centered goal setting; moderate (i.e., -500 kcal/day) caloric restriction ensuring protein (1-1.2 g/kg/day), calcium (1000-1200 mg/day), and vitamin D (800-1000 IU/day) needs are met; incorporation of RT (≥2 days/week) and moderate-intensity weight-bearing aerobic training (≥150 min/week); and delivery of care by a multidisciplinary team.