Height loss is related to aging changes in the bones, muscles, and joints . In total, aging may cause a loss of 1 to 3 inches in height. Men often gain weight until about age 50, then begin to lose weight. Women usually gain weight until age 70, then begin to lose weight. Weight loss is, in part, caused by a loss of muscle tissue.
Some weight loss is caused by loss of subcutaneous fat stores.
Part of the weight loss is caused by loss of bone tissue. Loss of body water also contributes to weight loss. Changes in fat and lean body mass cause an aged person to develop a heavier-appearing body and thin arms and legs. Because there is less body water, dehydration occurs readily. Doses of some medications may need to be adjusted because of changes in body water and fat.