Is Weight Loss Harmful for Skeletal Health in Obese Older Adults?

Purpose of Review: In view of the existing uncertainty about the implications of intentional weight loss in older obese adults, the present review (a) summarizes the available evidence from epidemiological and interventional studies concerning the effects of weight loss through lifestyle modifications on skeletal health parameters in older overweight/obese individuals, (b) proposes mechanisms that link weight loss to bone loss in this age group, and (c) identifies appropriate animal models. Main Findings and Future Directions: Based on prospective epidemiological studies, weight loss is associated with bone loss, impaired bone macro- and microstructure, and increased fracture risk in the elderly. Data from interventional studies confirm the negative effects of intentional weight loss achieved by lifestyle modifications on skeletal health outcomes in obese older individuals. These effects appear to be modest following a single weight loss attempt, but may persist in the longer term, and presumably, during subsequent weight loss efforts. Current evidence suggests that resistance exercise coupled with caloric restriction mitigates bone and muscle loss. However, alternative strategies do not exist for older individuals, especially those who are unable or unwilling to exercise. Clinical weight loss studies in obese older individuals and preclinical research in relevant animal models with obesity and osteoporosis are required. These will advance our understanding of the pathophysiology of weight-loss-associated skeletal alterations and provide evidence on how bone loss can be counteracted or prevented.