Body weight and body composition in old age and their relationship with frailty.

PURPOSE OF REVIEW: Aging is associated with various changes in body composition, including changes in weight, loss of muscle mass, and increase in fat mass. This article describes the role of body weight and body composition, and their changes, in the risk of frailty in old age. RECENT FINDINGS: Based on current literature, observational studies on obesity and high waist circumference show most convincing results for an association with frailty. The independent role of muscle mass and muscle fat infiltration remains unclear, mainly due to a lack of studies and a lack of accurate measurement of body composition by computed tomography or MRI. Weight loss and exercise training intervention studies can be of benefit to frail older adults. SUMMARY: Obesity and high waist circumference may be important determinants of frailty in old age, whereas the role of muscle mass and muscle fat infiltration is still unclear. More prospective studies that will specifically focus on frailty as an outcome measure are needed to identify specific body composition components as potential targets for the prevention of frailty in old age.