Surgical patients are usually starved for 8 to 12 hours before operation in order to reduce the chances of vomiting and other complications during the anaesthetic. Recent studies have suggested that this period of starvation might be harmful as it 'weakens' or 'stresses' the body before the operation. To avoid these harmful effects of starvation, patients are now given carbohydrate drinks (sugar-containing drinks that provide energy for the body) up to 2 hours before the operation. These drinks have been shown to make patients feel better, reduce sickness after the anesthetic/surgery and result in quicker recovery from operation. But the ways in which the sugar drinks have these beneficial effects on the body are unknown. The optimum time of giving these drinks to patients before operation is also unknown. This study will investigate the hormone responses of the body, following intake of 2 different carbohydrate drinks, in order to determine the optimum time of intake of these drinks in order to obtain the maximum benefits for the body.