The primary thing that needs to be considered is the basal metabolic rate that regulates the amount of calorie expended by the body for existence. Definitely as the net body mass becomes low on shrinkage with lowered bone density and body fat, the lowered calorie intake induces the body to burn lesser energy. Lowering of BMR is somewhat a self induced adjustment due to the metabolic changes associated with shrinkage helping the body to function as an efficient energy saver, thereby burning lesser calories. (United Nations University, 2008)
The next important adaptation related to the shrinkage must be a lower cardiac output due to the lower aerobic capacity. The lowered cardiac output that is the extent of oxygen transport from the heart to the cells of the body is related to the overall cardiovascular requirements of the body. A low cardiac output is definitely coupled with the lowered tidal volume of respiration in a reduced body with a decrease in the cardiac tissue mass.
There is a formidable relationship between body mass, body size and blood pressure level. In fact blood pressure has been found to vary directly to the body height. The body being smaller in size hardly requires much pumping pressure to transmit blood to the rest of the body. ...