Does fat mass increase or get redistributed with aging?
The loss of lean mass with aging is accompanied by an increase in overall fat mass. Specifically, there is an increase in total adiposity and a shift from lower body subcutaneous fat to more abdominal visceral fat depots with advancing age. An increase in central adiposity begins in young men who gain excess fat, but this does not appear to occur in women until around the time of the menopausal transition. Aging is also associated with an increase in fat deposition in other ectopic depots, including cardiac and skeletal muscle tissues. Although the loss of lean mass was once thought to be the primary determinant of physical disability in old age, recent studies indicate that increased adiposity is an independent, and perhaps stronger, predictor of disability in older individuals. The infiltration of fat in skeletal muscle is associated with reduced lower leg strength and power, and impaired physical function. This, combined with an increase in visceral adiposity, may play a role in age-associated insulin resistance.